U.S. patent application number 16/791656 was filed with the patent office on 2020-08-13 for methods for controlling plant pathogens using n-phosphonomethylglycine.
The applicant listed for this patent is Monsanto Technology LLC. Invention is credited to William P. Clinton, Paul C.C. Feng, James F. Mitchell, David V. Uhr.
Application Number | 20200253213 16/791656 |
Document ID | 20200253213 / US20200253213 |
Family ID | 1000004794542 |
Filed Date | 2020-08-13 |
Patent Application | download [pdf] |
United States Patent
Application |
20200253213 |
Kind Code |
A1 |
Clinton; William P. ; et
al. |
August 13, 2020 |
METHODS FOR CONTROLLING PLANT PATHOGENS USING
N-PHOSPHONOMETHYLGLYCINE
Abstract
The present invention relates to compositions and methods for
disease control in plants. The compositions for use in the methods
of the invention include glyphosate as the active compound. In
addition, methods and compositions are disclosed to prevent and
treat pest infection in glyphosate tolerant plants.
Inventors: |
Clinton; William P.;
(University City, MO) ; Feng; Paul C.C.; (Creve
Coeur, MO) ; Mitchell; James F.; (Cleveland, MS)
; Uhr; David V.; (Henderson, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Monsanto Technology LLC |
St. Louis |
MO |
US |
|
|
Family ID: |
1000004794542 |
Appl. No.: |
16/791656 |
Filed: |
February 14, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14835612 |
Aug 25, 2015 |
10575526 |
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16791656 |
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11061681 |
Feb 22, 2005 |
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14835612 |
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60654442 |
Feb 18, 2005 |
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60622134 |
Oct 26, 2004 |
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60557403 |
Mar 30, 2004 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C12N 15/8281 20130101;
C12N 15/8275 20130101; C12N 15/8282 20130101; A01N 57/20
20130101 |
International
Class: |
A01N 57/20 20060101
A01N057/20; C12N 15/82 20060101 C12N015/82 |
Claims
1-50. (canceled)
51. An admixture of a glyphosate compound and a plant pest control
compound for use on a glyphosate tolerant crop plant to prevent or
control plant damage caused by a plant pest on said crop, wherein
said admixture is applied to said crop at a dose less than that
normally applied for said glyphosate compound or said pest control
compound.
52. The admixture of claim 51, wherein the pest control compound is
a systemic or a contact fungicide compound.
53. The admixture of claim 52, wherein said fungicide compound is
selected from the group consisting of members of the chemical
groups strobilurins, triazoles, chloronitriles, carboxamides and
mixtures thereof.
54. The admixture of claim 51, wherein said pest control compound
is an insecticide.
55. A container of a mixture of glyphosate compound and a pest
control compound, wherein said container has a volume of at least
0.5 liters.
56. The container of claim 55, wherein said pest control compound
is a fungicide compound.
57. The container of claim 55, wherein said pest control compound
is an insecticide compound.
58. The container of claim 55, wherein said container comprises an
instruction means for use of said mixture.
59. (canceled)
60. A method to reduce fungal resistance to a fungicide, the method
comprising, providing the admixture of claim 52 to a crop plant
that is susceptible to a fungal plant pathogen, wherein the
glyphosate compound and the fungicide compound have different modes
of action to prevent or reduce fungal disease in said plant.
62-63. (canceled)
64. A kit for controlling pathogens on a glyphosate tolerant crop,
other than wheat, the kit comprising: a) a composition comprising
glyphosate and b) an instruction means for applying said
composition in a first application to control weeds and a second
application to said crop to control a plant pathogen.
65. The kit of claim 64, wherein said instruction means is selected
from the group consisting of written instructions, audio
instructions, pictorial instructions and video instructions.
66. The kit of claim 64, wherein the pathogen is a fungus.
67. The kit of claim 66, wherein the fungus has a glyphosate
sensitive 5-enolpyruvylshikimate-3-phosphate synthase.
68. The admixture of claim 52, wherein the admixture is used to
reduce fungal resistance to the fungicide.
69. The admixture of claim 51, wherein the glyphosate compound and
the pest control compound have different modes of action to prevent
or reduce plant damage caused by said plant pest on said crop.
70. A kit for to preventing or controlling plant damage on a
glyphosate tolerant crop, the kit comprising: a) the admixture of
claim 51; and b) an instruction means for applying said admixture
to said glyphosate tolerant crop.
71. The method of claim 60, wherein the fungicide compound is
selected from the group consisting of members of the chemical
groups strobilurins, triazoles, chloronitriles, carboxamides, and
mixtures thereof.
Description
[0001] This application claims benefit under 35USC .sctn. 119(e) of
U.S. provisional application Ser. No. 60/557,403 filed Mar. 30,
2004, U.S. provisional application Ser. No. 60/622,134 filed Oct.
26, 2004, and U.S. provisional application serial number [Atty.
Dkt. 16518.136PV] filed Feb. 18, 2005, herein incorporated by
reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to methods and compositions
for pest control in plants. More particularly, it relates to
methods and compositions for controlling, preventing, or treating
plant pathogens using N-phosphonomethylglycine and compositions
containing N-phosphonomethylglycine in plants tolerant to
N-phosphonomethylglycine.
BACKGROUND
[0003] The development of herbicide tolerant crops allows for the
greater use of post-emergent herbicides during agricultural
cultivation of the crop. One example of a post-emergent herbicide
is N-phosphonomethylglycine, also known as glyphosate, a well known
herbicide that has activity on a broad spectrum of plant species.
Glyphosate is the active ingredient of Roundup.RTM. (Monsanto Co.,
St. Louis, Mo.), a safe herbicide having a desirably short
half-life in the environment. When applied onto a plant surface,
glyphosate moves systemically through the plant. Glyphosate is
toxic to plants by inhibiting an enzyme in the shikimic acid
pathway that provides a precursor for the synthesis of aromatic
amino acids. Plants, fungi and some bacteria contain the
5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme that is
sensitive to the toxic effects of glyphosate.
[0004] Farmers typically rely on genetic resistance to provide
protection from plant pathogen infection and disease. However,
sufficient genetic resistance is not always available in the crops
being produced or undesirable traits are linked to the genetic
resistance genetic loci. Farmers must then apply pesticides to
control the pathogen infections, significantly increasing the cost
of growing the crops and impact to the environment.
[0005] Controlling the crop loss to fungal diseases is expensive.
The United States Department of Agriculture estimated that
fungicide use to combat the Asian soybean rust alone could add $25
an acre, or 15 percent to 20 percent, to the cost of growing
soybeans. If fungicides were applied to all U.S. fields planted
with soybeans in 2004, it would cost farmers a total of about $1.87
billion.
[0006] It would be advantageous to develop methods and chemical
mixtures for controlling pathogens and disease in glyphosate
tolerant crop plants using compositions that are effective and
safe. Such methods would reduce the cost of growing crops by
reducing the number of inputs a farmer uses to treat a crop field
while providing protection from losses do to plant disease.
SUMMARY OF THE INVENTION
[0007] The present invention provides a method of controlling plant
pathogen disease in a glyphosate tolerant crop plant where the
method comprises, identifying a crop plant in need of disease
control, and contacting the plant with an effective amount of a
composition having glyphosate, whereby the disease of the crop
plant by a plant pathogen is controlled. In particular, the plant
pathogen is a fungus and has a glyphosate sensitive
5-enolpyruvylshikimate-3-phosphate synthase.
[0008] The present invention also provides a method of preventing
disease in a glyphosate tolerant crop plant by a pathogen where the
method comprises, identifying a crop plant at risk of pathogen
infection, and contacting at least a portion of the crop plant with
an effective amount of glyphosate to prevent infection of the plant
by a plant pathogen. In particular, the plant pathogen is a fungus
and has a glyphosate sensitive 5-enolpyruvylshikimate-3-phosphate
synthase.
[0009] The present invention further provides a method of treating
a plant disease that comprises, identifying a glyphosate tolerant
crop plant infected with a plant pathogen, and contacting the crop
plant with an effective amount of a composition comprising
glyphosate. In particular, the plant pathogen is a fungus and has a
glyphosate sensitive 5-enolpyruvylshikimate-3-phosphate
synthase.
[0010] The present invention also provides a method of controlling
weeds and pathogens in a field of glyphosate tolerant crop plants,
where the method comprises applying a first composition comprising
an herbicidal composition, and applying a second composition
comprising an effective amount of glyphosate, where the second
composition controls a disease of the crop plants by a plant
pathogen that has a glyphosate sensitive
5-enolpyruvylshikimate-3-phosphate synthase.
[0011] The present invention further provides a method of
increasing the yield of a glyphosate tolerant crop plant, the
method comprising, growing a crop plant having an exogenous nucleic
acid molecule encoding a polypeptide, where the polypeptide confers
tolerance to glyphosate, identifying said crop plant as in need of
disease control, applying a composition comprising glyphosate to
the plant to control a plant pathogen that has a glyphosate
sensitive 5-enolpyruvylshikimate-3-phosphate synthase, and
harvesting from the crop plant a tissue or seed, wherein the yield
increase is due to control of the disease.
[0012] The present invention also provides an admixture of a
glyphosate compound and a pest control compound. Preferably, the
admixture comprises a glyphosate compound and a fungicide compound
for use on a glyphosate tolerant crop plant to prevent or control
plant disease caused by a plant pathogen, in particular, the plant
pathogen is a fungus and has a glyphosate sensitive
5-enolpyruvylshikimate-3-phosphate synthase. The fungicide compound
of the admixture may be a systemic or contact fungicide or mixtures
of each. More particularly the fungicide compound includes, but is
not limited to members of the chemical groups strobilurins,
triazoles, chloronitriles, carboxamides and mixtures thereof. The
pest control compound in the admixture with glyphosate further
comprises an insecticide compound, thereby reducing the numbers of
chemical applications to a field of glyphosate tolerant plants.
[0013] The present invention provides a method to reduce the crop
residues and environmental residues of a glyphosate compound and a
fungicide compound by formulating an admixture of the compounds,
and applying to a crop plant a dose that is less than the dose
normally applied to a crop plant of each compound, wherein the
treated crop plant is protected from crop losses due to fungal
disease, and the glyphosate and fungicide residues in the plant or
environment are reduced.
[0014] The present invention also provides a method to reduce
fungal resistance to a fungicide by providing an admixture of a
glyphosate compound and a fungicide compound, and treating a crop
plant that is susceptible to a fungal pathogen, wherein the
compounds have different modes of action to prevent or reduce
fungal disease.
[0015] The present invention also provides a method for treating
leaf rust in a soybean plant comprising identifying a soybean plant
as being infected with rust, and applying a composition having
glyphosate to the soybean plant or portion thereof, whereby the
composition results in the disease being controlled. In another
aspect the treatment is a composition having a glyphosate and a
fungicide composition to the soybean plant or portion thereof,
whereby the composition results in the disease being
controlled.
[0016] The present invention also provides a method for preventing
leaf rust in a soybean plant comprising identifying a soybean plant
as being at risk of infection by rust, and applying a composition
having glyphosate to the soybean plant or portion thereof, whereby
the infection is inhibited in the soybean plant. In another aspect
of the invention, a composition having a glyphosate compound and a
fungicide compound is applied to the soybean plant or portion
thereof, whereby the infection is inhibited in the soybean
plant.
[0017] The present invention also provides a method for treating
leaf rust in a corn plant comprising identifying a corn plant as
being infected with rust, and applying a composition having
glyphosate to the corn plant or portion thereof, whereby the
composition results in the disease being controlled.
[0018] The present invention also provides a method for treating
leaf rust in a corn plant comprising identifying a corn plant as
being infected with rust, and applying a composition having a
glyphosate compound and a fungicide compound to the corn plant or
portion thereof, whereby the composition results in the disease
being controlled.
[0019] The present invention also provides a method for preventing
leaf rust in a corn plant comprising identifying a corn plant as
being at risk of infection by rust, and applying a composition
having glyphosate to the corn plant, whereby the infection is
inhibited in the corn plant.
[0020] The present invention also provides a method for preventing
leaf rust in a corn plant comprising identifying a corn plant as
being at risk of infection by rust, and applying a composition
having a glyphosate compound and a fungicide compound to the corn
plant, whereby the infection is inhibited in the corn plant.
[0021] The present invention also provides a method for treating a
fungal wilt disease in a cotton plant comprising identifying a
cotton plant as being infected with the fungal wilt pathogen, and
applying a composition having glyphosate to the cotton plant or
portion thereof, whereby the composition results in the disease
being controlled. In another aspect of the method, the glyphosate
composition comprises a plant systemic fungicide.
[0022] The present invention also provides a method for preventing
a fungal wilt disease in a cotton plant comprising identifying a
cotton plant as being at risk of infection by a fungal wilt
pathogen, and applying a composition having glyphosate to the
cotton plant, whereby the infection is inhibited in the cotton
plant. In another aspect of the method, the glyphosate composition
comprises a plant systemic fungicide.
[0023] The present invention also contemplates a glyphosate
containing composition that is enhanced for the uptake into
glyphosate tolerant crops or fungal pathogens of those crops. In
another aspect of the present invention, the glyphosate composition
comprises an adjuvant.
[0024] A method to control a fungal disease in a glyphosate
tolerant crop plant comprising treatment of the crop plant with an
effective dose of a glyphosate composition, wherein the crop plant
is selected from the group consisting of Roundup Ready.RTM. Cotton
1445 and 88913; Roundup Ready.RTM. corn GA21, nk603, MON802,
MON809; Roundup Ready.RTM. Sugarbeet GTSB77 and H7-1; Roundup
Ready@ Canola RT73 and GT200; oilseed rape ZSR500, Roundup
Ready.RTM. Soybean 40-3-2, Roundup Ready.RTM. Bentgrass ASR368, and
Roundup Ready.RTM. potato RBMT22-082. Preferably, the glyphosate
composition is in a formulation comprising Roundup WeatherMAX.RTM.,
more preferably the glyphosate composition contains a
fungicide.
[0025] A method for controlling a fungal disease in a glyphosate
tolerant crop plant comprising treatment of a crop plant cell with
a glyphosate composition, wherein a chemical exchange between the
crop plant cell and a fungal cell occurs allowing movement of the
glyphosate into the fungal cell from the crop plant cell, and the
fungal cell contains a glyphosate sensitive EPSPS enzyme. In
another aspect of the method, the glyphosate composition comprises
a plant systemic fungicide.
[0026] The present invention also provides a container comprises a
glyphosate compound and a pest control compound. In another aspect
of the invention, a kit is provided for controlling pathogens on
crop plants, comprising, a composition comprising glyphosate, and
an instruction means for applying the composition in a first
application to control weeds and a second application to a crop
plant to control a plant pathogen. In particular, the plant
pathogen is a fungus and has a glyphosate sensitive
5-enolpyruvylshikimate-3-phosphate synthase.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a graph depicting a decrease in rust disease
infection with an increase in glyphosate treatment. In the data
shown in FIG. 1, the top fully expanded wheat leaf was shielded
from Roundup.RTM. spray (0-1.times., 1.times. at 0.75 lb ae/a)
followed by inoculation of wheat rust spores to the shielded leaf
at 1 day after treatment (DAT).
[0028] FIG. 2 shows the comparison of Roundup WeatherMAX.RTM. and
Touchdown.TM. IQ for controlling wheat rust disease when applied
before (preventative) or after (curative) inoculation with wheat
rust spores, glyphosate formulation were applied at 1/8.times. to
1.times. rates in Roundup Ready Wheat.RTM..
DETAILED DESCRIPTION
[0029] The present invention relates to methods and compositions
for disease control, prevention or treatment in plants. In a
preferred aspect, the methods of the invention relate to methods of
controlling, preventing or treating disease in glyphosate tolerant
crop plants.
[0030] Typically, glyphosate compositions have been applied as an
herbicide. Surprisingly, it has been found that glyphosate
compositions also have pesticidal properties. In a preferred
aspect, the glyphosate compositions have fungicidal activity when
used on glyphosate tolerant crop plants. In another aspect of the
invention, a composition that comprises a glyphosate compound and a
fungicide compound has been shown to be particularly effective in
controlling fungal disease. A reduced dosage rate of each compound
than that normally applied to control weeds or fungal disease has
been shown to be effective in controlling fungal disease.
[0031] As such, the present invention provides methods of using
glyphosate compositions or admixtures containing glyphosate and a
fungicide for controlling, preventing or treating plant pathogen
infection in glyphosate tolerant crop plants. These methods are
useful in the control, prevention or treatment of plant disease,
for example, fungal diseases in soybean, wheat, corn, rice, canola,
alfalfa, sugarbeet, potato, tomato, cotton or other crop plants
genetically modified for glyphosate tolerance.
[0032] The section headings are used herein for organizational
purposes only, and are not to be construed as in any way limiting
the subject matter described.
I. Methods of the Present Invention
[0033] The present disclosure provides methods for controlling,
preventing or treating disease in crop plants by applying
compositions containing N-phosphonomethylglycine and the salts
thereof (also referred to herein as glyphosate compound) to a crop
plant in need of disease control, prevention or treatment. In one
aspect, the methods include contacting a crop plant in need of
disease control, prevention or treatment with an effective amount
of a chemical composition containing glyphosate to control, prevent
or treat a plant pathogen infection in the crop plant. In a
preferred aspect, the crop plant for which disease control,
prevention or treatment is desired is glyphosate tolerant.
[0034] As used herein "disease control" refers to preventing or
treating a pathogen infection in a plant. It is intended that the
plants avoid or minimize the disease or symptoms thereof that are
the outcome of various plant-pathogen interactions. That is,
pathogens are prevented from causing plant diseases or the
associated disease symptoms or both, or alternatively, the disease
or associated disease symptoms are minimized or lessened in plants
treated with a glyphosate composition compared to an untreated
plant. In a preferred aspect, infection is prevented or controlled
through glyphosate activity on the pathogen. While the invention
does not depend on any particular reduction in the severity of
disease symptoms, the methods of the invention will in one aspect
reduce the disease symptoms resulting from a pathogen infection by
at least about 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%
compared to a plant not treated with a glyphosate composition (or
an "untreated plant"). Hence, the methods of the invention include
those that can be utilized to protect plants from disease,
particularly those diseases that are caused by plant pathogens. A
reduction in infection or disease symptoms can be measured using
any reproducible means of measurement. In one aspect, a reduction
in infection or disease symptoms is measured by counting the number
of lesions, pustules, or both on a leaf surface and comparing to
the number of lesions, pustules or both on an untreated plant.
[0035] As used herein, a "plant in need" refers to any plant for
which disease control, prevention or treatment is desired. In
particular, the term refers to a plant that is at risk of being
infected by a plant pathogen, or is infected by a pathogen. A plant
may be at risk of infection in circumstances where pathogens are
more likely to infect the plant, for example, in disease optimal
climate conditions or where other disease hosts in a field have
been treated with a herbicide and disease crossover from the dying
plant to the standing plant is possible. An infected plant can be
identified through observation of disease symptoms on the plant.
The disease symptoms expressed will depend on the disease, but in
general the symptoms include lesions, pustules, necrosis,
hypersensitive responses, wilt, chlorosis, induction of defense
related genes (e.g. SAR genes) and the like.
[0036] Disease infections or associated symptoms can be identified
by any means of identifying infection or related symptoms. Various
methods are available to identify infected plants and the
associated disease symptoms. In one aspect, the methods may involve
macroscopic or microscopic screening for infection and/or symptoms,
or the use of microarrays for detection of infection related genes
(e.g. Systemic Acquired Resistance genes, defensin genes, and the
like). Macroscopic and microscopic methods for determining pathogen
infection in a plant are known in the art and include the
identification of damage on plant tissue caused by infection or by
the presence of lesions, necrosis, spores, hyphae, growth of fungal
mycelium, wilts, blights, spots on fruits, rots, galls and stunts,
and the like. Such symptoms can be compared to non-infected plants,
photos or illustrations of infected plants or combinations thereof
to determine the presence of an infection or the identity of the
pathogen or both. Photos and illustrations of the symptoms of
pathogen infection are widely available in the art and are
available for example, from the American Phytopathological society,
St. Paul, Minn. 55121-2097. In one aspect, the symptoms are visible
to the naked eye or by a specified magnification. In a preferred
aspect, the specified magnification is 2.times., 3.times.,
4.times., 5.times., 10.times., or 50.times..
[0037] In another aspect, the infection or associated symptom can
be identified using commercially available test kits to identify
pathogens in plants. Such test kits are available, for example,
from local agricultural extensions or cooperatives. In another
aspect, identifying a crop plant in need of treatment is by
prediction of weather and environmental conditions conducive for
disease development. In another aspect, persons skilled in scouting
fields of crop plants for plant disease identify a crop in need of
treatment.
[0038] In yet another aspect, an infection or associated symptom
can be identified using Polymerase chain reaction (PCR)-based
diagnostic assays. PCR-based assays are described for example to
detect the presence of Gaeumannomyces graminis (GGT, Take-all
disease) in infected wheat using PCR amplification of sequences
specific to the pathogen mitochondrial genome (Schlesser et al.,
1991; Applied and Environ. Microbiol. 57: 553-556), and random
amplified polymorphic DNA (i.e. RAPD) markers to distinguish
numerous races of Gremmeniella abietina, the causal agent of
scleroderris canker in conifers. U.S. Pat. No. 5,585,238
(incorporated by reference in its entirety) describes primers
derived from the ITS sequences of the ribosomal RNA gene region of
strains of Septoria, Pseudocercosporella, and Mycosphaerella and
their use in the identification of these fungal isolates using
PCR-based techniques. In addition, U.S. Pat. No. 5,955,274
(incorporated by reference in its entirety) describes primers
derived from the ITS sequences of the ribosomal RNA gene region of
strains of Fusarium and their use in the identification of these
fungal isolates using PCR-based techniques. Furthermore, U.S. Pat.
No. 5,800,997 (incorporated by reference in its entirety) describes
primers derived from the ITS sequences of the ribosomal RNA gene
region of strains of Cercospora, Helminthosporium, Kabatiella, and
Puccinia and their use in the identification of these fungal
isolates using PCR-based techniques. The specific methods of
identification will depend on the pathogen.
[0039] As used herein, "contacting" refers to treatment of a crop
plant with a glyphosate composition either directly on a crop
plant, or immediately adjacent to the crop plant where the
glyphosate can be taken-up into the crop plant's vascular system.
In methods where the composition is directly contacted with the
crop plant, the composition may be contacted with the entire crop
plant or with only a portion of the plant. Additionally, a plant
pathogen may be contacted with the glyphosate composition either by
direct contact on a plant surface or by contacting a plant cell or
tissue that contains glyphosate. In a preferred aspect, a plant is
contacted with a glyphosate composition by overhead spraying of the
composition.
[0040] The term "effective amount" means an amount of the
glyphosate compound sufficient to result in any observable measure
of disease control, prevention or treatment in a plant. Preferably,
an effective amount of glyphosate results in a concentration of
glyphosate in a plant tissue of between about 0.01 parts per
million (ppm) to about 100 ppm per fresh weight. More preferable,
tissue concentrations of between 0.1 ppm and 25 ppm glyphosate of
fresh weight are obtained in the tissues of plants treated in the
methods of the present invention. Most preferably, tissue
concentrations of between about 0.5 ppm and about 10 ppm glyphosate
are effective in controlling, preventing or treating disease in a
treated plant.
[0041] Effective rates of application in the present invention for
a glyphosate compound can be influenced by many factors including
the environment and should be determined under actual use
conditions. Preferably, the disease control, prevention or
treatment is obtained with an application of glyphosate at a rate
similar to or less than the amount used for weed control. More
preferably, a rate of application of a glyphosate compound from
about 0.1 pounds acid equivalent/acre (lb ae/acre, herein referred
to lb/acre) to about 5 lb/acre of glyphosate is effective in
controlling, preventing or treating a pathogen in accordance with
the method of the present invention. Yet more preferable are rates
of application ranging from about 0.37 lb/acre to about 2.5
lb/acre. Most preferable are rates of application of about 0.75
lb/acre, herein referred to as 1.times. glyphosate rate.
[0042] In a preferred aspect plant disease control, prevention or
treatment is accomplished by applying an effective amount of a
glyphosate composition either pre- or post-infection, to the whole
plant or a portion of the plant such as the roots, stems, foliage,
fruit, seeds, tubers or bulbs, or to the media (e. g., soil, sand
or water) in which the plants to be protected are growing. In one
aspect, a glyphosate is translocated through the vascular system in
plants and therefor the entire plant is not required to be
contacted. Thus, in one aspect a portion of a plant may be treated
with a glyphosate composition, and a disease controlled, prevented
or treated in the treated portion as well as in untreated portions
of the plant, such as untreated leaves, stems, or roots. In one
particular aspect, untreated leaves of glyphosate tolerant wheat
plants have decreased disease infection when lower leaves are
treated with a composition containing glyphosate. In a particularly
preferred aspect, disease control, prevention or treatment
corresponds to the concentration of glyphosate in the tissue of the
untreated leaf. In another aspect, a glyphosate composition can
also be applied to the seed to protect the seed and seedling.
[0043] As used herein, "pre-infection" refers to a condition in
which a plant has not been exposed to a plant pathogen or a
material contaminated with a plant pathogen.
[0044] The term "post-infection" refers to a condition where a
plant has been exposed to a plant pathogen or a material
contaminated with a plant pathogen. The plant may or may not be
showing symptoms of the infection. For example, the plant may be
infected with a pathogen yet not showing signs of the infection,
e.g., a hypersensitive response (HR).
[0045] Preferably, the methods of the present invention control,
prevent or treat disease in a plant through the direct action of
the glyphosate composition on the plant pathogen. Disease control,
prevention or treatment may also be, in part, the result of
systemic acquired resistance (SAR) induced by the application of
the glyphosate composition. In a preferred aspect, the disease
control, prevention or treatment obtained by the methods of the
present invention is the result of the direct action of the
glyphosate and not the result of induced SAR.
[0046] By "glyphosate tolerant" is meant that the plants for use in
the methods are resistant to glyphosate application or tolerant of
glyphosate. In a preferred aspect of the present invention
glyphosate tolerant plants are the result of the expression of an
exogenous nucleic acid molecule providing tolerance to
glyphosate.
[0047] As such, the present invention provides methods of
preventing disease in a plant by applying an effective amount of a
glyphosate composition to a plant, such that infection of a plant
by a pathogen is prevented. In one preferred aspect, the plant for
use in the methods is glyphosate tolerant.
[0048] By "preventing infection" is intended that the plants avoid
pathogen infection or disease symptoms or both, or exhibit reduced
or minimized pathogen infection or disease symptoms or both, that
are the natural outcome of plant-pathogen interactions when
compared to plants lacking treatment with glyphosate compositions
(or "untreated plants"). That is, pathogens are prevented or
reduced from causing disease, the associated disease symptoms or
both. The methods of the invention can be utilized to protect
plants from disease, particularly those diseases that are caused by
fungal plant pathogens.
[0049] By preventing or reducing pathogen infection or the related
disease symptoms, the infection or symptoms or both are preferably
reduced at least about 10% from a plant untreated by a glyphosate
composition. Preferably, the infection, symptoms or both are
prevented or reduced at least about 20%, 30%, 40%, 50%, 60%, 70%,
80% compared to infection, symptoms or both on a plant not treated
with a glyphosate composition. Disease infection may be measured by
any reproducible means of measurement. In one aspect, infection may
be measured by counting lesions or pustules visible to the naked
eye, or at a specified magnification. In a preferred aspect, the
specified magnification is 2.times., 3.times., 4.times., 5.times.,
10.times., or 50.times..
[0050] In a preferred aspect, the methods of the present invention
provide for disease prevention for a period of time after treatment
with a glyphosate composition. Preferably, the glyphosate
composition prevents severe disease of the plant for several weeks
after application of the glyphosate composition. More preferably,
disease is prevented at least about 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30, 35 days after treatment with a
glyphosate composition. In one especially preferred aspect, disease
is prevented for at least about 40 days after treatment of the
plant with a glyphosate composition. Prevention of disease may be
measured by any reproducible means of measurement. In a preferred
aspect, disease prevention is measured by counting lesion or
pustule development at time points after treatment with a
glyphosate composition. In a preferred aspect, the lesions or
pustules are counted 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20, 25, 30 days after glyphosate treatment.
[0051] As discussed more fully below, depending on the method
employed for conferring glyphosate tolerance or resistance,
application of glyphosate may prevent infection or disease for
shorter or longer periods of time after treatment. For example,
where glyphosate tolerance is imparted to a plant by an exogenous
DNA encoding a polypeptide that degrades glyphosate (e.g.
glyphosate oxidoreductase or glyphosate acetyl transferase),
disease will be prevented for a shorter period of time compared to
a glyphosate tolerance imparted by the expression of an exogenous
polypeptide that is less inhibited by glyphosate (e.g. a modified
EPSPS) allowing glyphosate conservation in plant tissues.
Glyphosate tolerance in plants can be achieved by the expression of
a modified class I EPSPS that has lower affinity for glyphosate,
however, still retains their catalytic activity in the presence of
glyphosate (U.S. Pat. Nos. 4,535,060, and 6,040,497 (both of which
are incorporated by reference in their entirety)). EPSPS enzymes,
such as, class II EPSPSs have been isolated from bacteria that are
naturally resistant to glyphosate and when the enzyme is expressed
as a gene product of a transgene in plants provides glyphosate
tolerance to the plants (U.S. Pat. Nos. 5,633,435 and 5,094,945
(both of which are incorporated by reference in their entirety)).
The present invention contemplates the use of any EPSPS enzyme,
modified or naturally occurring, for example, glyphosate resistant
EPSPS enzymes isolated from microbial sources that are not Class I
or Class II enzymes, and modified Class I EPSPSs (WO04/07443
(incorporated by reference in its entirety)), that have resistance
to glyphosate for use as a transgene in a transgenic plant. Such
enzymes are known to those skilled in the art of making glyphosate
tolerant plants.
[0052] In another aspect, application of a glyphosate composition
is effective in preventing disease or the associated symptoms at a
site on the plant distant from the point at which the glyphosate
compositions are applied. In one aspect, foliar application of the
glyphosate compositions is effective in preventing pathogens from
colonizing relatively distant and inaccessible regions of the
plant, such as the roots and meristems. In another aspect, disease
prevention in leaves of a plant is obtained through contacting the
medium in which the plant is growing. This remote effect occurs
because the glyphosate compounds are transported in the plant
vascular system, which allows for long distance transport of the
compounds within living plants. In addition, disease prevention may
be enhanced by application of the glyphosate formulations through
induction of systemic acquired resistance (SAR). SAR occurs in
plants in response to infection, particularly by necrotizing
pathogens, or induced by certain compounds, and provides enhanced
resistance to subsequent attacks by the same or even unrelated
pathogens. SAR provides long-term (weeks to months) protection
throughout the plant (systemic) against a broad range of unrelated
pathogens. Examples of defense responses induced in plant cells
include the synthesis of plant cell structural components such as
cutin suberin, callose and lignin, chemical defense compounds such
as hydrogen peroxide, and anti-bacterial or anti-fungal compounds
such as tannins and phytoalexins. In a preferred aspect, disease is
prevented in a plant primarily through the direction action of
glyphosate rather than through induction of SAR.
[0053] Thus, methods of preventing disease in a plant are provided
where only a portion of the plant is contacted with a glyphosate
composition, yet untreated portions of the plant are also protected
from disease. In one aspect, only about 5%, 10%, 20%, 30%, 50%, 75%
or 90% of the plant is contacted with the glyphosate composition.
The percentage of plant contacted by the glyphosate composition may
be measured by any reproducible means of measurement.
[0054] One aspect of the present invention provides a method for
the prevention of infection in a soybean, corn, rice, cotton,
alfalfa, sugarbeet, or wheat plant. The method generally involves
applying an effective amount of a glyphosate composition to a
soybean, corn, rice, cotton, alfalfa, sugarbeet or wheat plant, or
part thereof to prevent infection of the plant. In one preferred
aspect, the soybean, corn, rice, cotton, alfalfa, sugarbeet, or
wheat plants are glyphosate tolerant. One particularly preferred
aspect provides methods for preventing the infection of soybean,
corn, cotton, or wheat plants by fungal pathogens. In a preferred
aspect methods for preventing infection by leaf rust on corn, wheat
and soybeans are provided. In another preferred aspect methods for
preventing infection and fungal wilt disease of cotton is
provided.
[0055] In another aspect, the methods of the present invention
provide for controlling, preventing or treating rust disease
(Phakopsora pachyrhizi) in soybean plants by application of
glyphosate compositions to a soybean plant in need of disease
control, prevention or treatment. In a preferred aspect, the
soybean is glyphosate tolerant.
[0056] Also provided are methods of treating a plant disease by
identifying a plant infected by a plant pathogen (i.e.
post-infection) and contacting the infected plant with an effective
amount of a glyphosate composition such that the infection is
treated. In a preferred aspect, the infected plant is glyphosate
tolerant. Infection can be measured by any reproducible means of
measurement. In one aspect, infection is measured by counting the
number of lesions visible to the naked eye, or at a specified
magnification. In a preferred aspect, the specified magnification
is 2.times., 3.times., 4.times., 5.times., 10.times. or
50.times..
[0057] By "treating" a plant disease is meant that the symptoms
caused by the plant pathogen are reduced or do not progress in
severity. A reduction in severity means that the surface area of
the leaf exhibits less infection or reduced symptoms (e.g., by
percentage of leaf surface) on the treated plant at a time after
treatment compared to symptoms at the time of treatment. In one
aspect, infection is reduced 5%, 10%, 25%, 50%, or 75% compared to
an infected plant not treated with a glyphosate composition.
[0058] In another aspect, lesions are prevented from increasing in
size or progressing to the next level of infection or symptom. In a
preferred aspect, the lesions are reduced from progressing to
pustules. In one aspect, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90%, 95%, 99% of the lesions are prevented from becoming pustules
on the leaf surface. Lesion development may be measured by any
reproducible means of measurement. In one aspect, lesion
development may be measured by comparing the number of visible
pustules on a plant surface at a time after treatment with the
number of visible lesions on the plant surface at the time of
treatment with a glyphosate composition.
[0059] In addition, methods for treating infection of a plant by a
plant pathogen are provided wherein a non-infected portion of the
plant is treated with glyphosate. Such methods include determining
that the plant is infected with a plant pathogen, then applying a
composition containing glyphosate to a portion of the plant that is
not infected with the pathogen. Application of the glyphosate
composition to the non-infected area of the plant results in the
treatment of infection at another location on the plant.
[0060] The present invention also provides methods for controlling
harmful weeds and controlling, preventing or treating pathogens in
a field of glyphosate tolerant crop plants where the method uses
applications of glyphosate compositions. Such methods comprise one
or more applications of a glyphosate composition to a field of crop
plants tolerant or resistant to glyphosate, preferably two or more
applications. Preferably, the application or applications are timed
for effective weed control and effective disease control,
prevention or treatment in the treated plant. For example, without
limitation, a first application of glyphosate is applied at a time
when the application controls the weeds within the field of plants.
For example, without limitation, a second application is at a time
when the crop plants are either at risk of infection or have
already been infected by a plant pathogen. In one aspect, the
application of a glyphosate composition results in a concentration
of glyphosate in a plant tissue of between about 0.01 ppm to about
100 ppm per fresh weight. More preferable, tissue concentrations of
between 0.1 ppm and 25 ppm glyphosate of fresh weight are obtained
in the tissues of plants treated in the methods of the present
invention. Most preferably, concentrations of between about 0.5 ppm
and about 10 ppm glyphosate are effective in controlling,
preventing or treating disease in a treated plant.
[0061] Effective rates of application in the present invention for
a glyphosate composition can be influenced by many factors
including the environment and should be determined under actual use
conditions. Preferably, the rate of application of a glyphosate
composition from about 0.1 lb/acre to about 5 lb/acre of glyphosate
is effective in controlling, preventing or treating a pathogen in
accordance with a method of the present invention. Yet more
preferable are rates of application ranging from about 0.37 lb/acre
to about 2.5 lb/acre. Most preferable are rates of application of
about 0.75 lb/acre.
[0062] In one aspect, methods for controlling weeds and pathogens
in a field crop comprises the steps of (a) planting a crop in a
field, (b) substantially freeing the field of non-crop plants by
applying an herbicidal composition and (c) thereafter control,
prevent or treat disease by applying a glyphosate composition. In
such a method, it should be appreciated that the steps of planting
and substantially freeing can be interchanged. Thus, the field may
be substantially free of non-crop plants before planting the crop
in the field. In one aspect, the application of the herbicidal
composition and the disease control glyphosate application are 1
day apart, 2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 21 days apart. In
another aspect, the herbicidal and pesticidal applications are
greater than 5, 10, 20, 25, 30, 35, 40, 45, or 50 days apart.
[0063] In one aspect, the glyphosate composition is applied one or
more times during the growing season. In another aspect, the
glyphosate composition is applied 2, 3, 4, 5, 6, 7, 8, 9, 10 times
during the growing season to a plant in need of disease control,
prevention or treatment.
[0064] The present invention also provides methods for increasing
the yield of a plant, by growing a plant having an exogenous
nucleic acid molecule encoding a polypeptide, where the polypeptide
confers resistance to glyphosate, determining the plant is infected
or is at risk of being infected with a plant pathogen, applying a
composition comprising (comprising means "including but not limited
to) glyphosate to the plant to control, prevent or treat a plant
pathogen, and harvesting from the plant a tissue. In a preferred
aspect, such methods increase the yield of plant tissues including,
but not limited to: seeds, fruits, kernels, bolls, tubers, roots,
and leaves. In an aspect of the present invention, the yield is
increased 5%, 10%, 15%, 20%, 25%, 30%, 50% compared to plants not
treated with a glyphosate composition for disease control,
prevention or treatment. In a preferred aspect, the increase in
yield is measured relative to the dry weight of a seed or an
average in the increase in dry weight across a collection of seeds.
In a preferred aspect of the present invention a collection of
seeds is all, or a percentage of all, for example 25%, 50% or 75%,
of the seeds on an individual plant, a representative number of
seeds from a field or planting area subject to a method of the
present invention or in the case of a comparison not subject to a
method of the present invention. In a preferred aspect, the
representative number of seeds selected is sufficient for a
statistical analysis.
[0065] The present invention also provides a kit for the control,
prevention or treatment of plant disease, where the kit comprises a
container having a glyphosate composition and instructional
material for applying the glyphosate composition to control,
prevent or treat a plant pathogen infection in accordance with a
method of the present invention. The skilled artisan will
appreciate that the instructions for applying the glyphosate
composition in the methods of the present invention can be any form
of instruction means. Such instructions include, but are not
limited to, written instruction material (such as, a label, a
booklet, a pamphlet), oral instructional material (such as on an
audio cassette or CD) or video instructions (such as on a video
tape or DVD).
II. Glyphosate Compositions
[0066] The compositions for use in the methods of the present
invention include compositions having as their effective ingredient
N-phosphonomethylglycine, also referred to herein as glyphosate.
Thus, the compositions for use in the methods of the present
invention include any composition containing a glyphosate compound.
In particular, compositions containing a glyphosate compound and a
fungicide compound are additive or synergistic in activity against
susceptible fungal pathogens. Glyphosate is an effective broad
spectrum herbicide. Various methods are known for producing
glyphosate, as shown, for example, in U.S. Pat. Nos. 3,927,080;
3,956,370; 3,969,398; 4,147,719; and 4,654,429 (all of which are
incorporated by reference in their entirety). As used herein,
"glyphosate" refers to N-phosphonomethylglycine, a salt or ester
thereof, or a compound which is converted to glyphosate in plant
tissues or which otherwise provides glyphosate ion. This includes
the TMS salt of glyphosate (commercially available under the trade
Touchdown.TM.), as well as sulfosate and its salts. In one aspect
glyphosate, glyphosate salts or both that are useful in a method of
the present invention are disclosed in U.S. Pat. No. 3,799,758,
herein incorporated by reference in its entirety. In another aspect
many derivatives of N-phosphonomethylglycine will exhibit broad
spectrum pesticidal activity, and thus any such pesticidal
derivatives will be defined as glyphosate for the purposes of the
present invention. In another aspect, any formulation of glyphosate
is within the scope of the present invention. In one preferred
aspect, the glyphosate composition comprises salts of the cationic
and anionic form of glyphosate, more preferably, the anionic form
of glyphosate
[0067] The chosen glyphosate composition is preferably applied to
the plants to be protected or treated in the form of a composition
with further carriers, surfactants, adjuvants or other
application-promoting chemicals customarily employed in formulation
technology. Suitable carriers, surfactants, and adjuvants can be
solid or liquid and are the substances ordinarily employed in
formulation technology, for example, natural or regenerated mineral
substances, solvents, dispersants, wetting agents, tackifiers,
thickeners, binders or fertilizers.
[0068] A preferred method of applying a glyphosate composition is
application to the parts of the plants that are above the soil,
especially to the leaves (foliar application). The frequency and
rate of application depend upon the biological and climatic living
conditions of the pathogen. The composition can, however, also
penetrate the plant through the roots via the soil or via the water
(systemic action) if the locus of the plant is impregnated with a
liquid formulation (e.g. in rice culture) or if the composition is
introduced in solid form into the soil, e.g. in the form of
granules (soil application). In order to treat seed, the
composition can also be applied to the seeds (coating), either by
impregnating the tubers or grains with a liquid formulation of the
composition, or by coating them with an already combined wet or dry
formulation. In addition, in special cases, other methods of
application to plants are possible, for example treatment directed
at the buds or the fruit trusses.
[0069] The glyphosate compositions used in the methods of the
present invention can also be mixed with one or more other
insecticides, fungicides, nematocides, bactericides, acaricides,
growth regulators, chemosterilants, semiochemicals, repellents,
attractants, pheromones, feeding stimulants or other biologically
active compounds to form a multi-component pesticide giving an even
broader spectrum of agricultural protection. Examples of such
agricultural protectants with which compounds of this invention can
be formulated are: insecticides such as abamectin, acephate,
azinphos-methyl, bifenthrin, buprofezin, carbofuran, chlorfenapyr,
chlorpyrifos, chlorpyrifos-methyl, cyfluthrin, beta-cyfluthrin,
cyhalothrin, lambda-cyhalothrin, deltamethrin, diafenthiuron,
diazinon, diflubenzuron, dimethoate, esfenvalerate, fenoxycarb,
fenpropathrin, fenvalerate, fipronil, flucythrinate,
tau-fluvalinate, fonophos, imidacloprid, isofenphos, malathion,
metaldehyde, methamidophos, methidathion, methomyl, methoprene,
methoxychlor, methyl
7-chloro-2,5-dihydro-2-[[N-(methoxycarbonyl)-N-[4-(trifluoromethoxy)pheny-
l]amino]carbonyl]indeno-[1,2-e][1,3,4]oxadiazine-4a(3H)-carboxylate
(DPX-JW062), monocrotophos, oxamyl, parathion, parathion-methyl,
permethrin, phorate, phosalone, phosmet, phosphamidon, pirimicarb,
profeno-fos, rotenone, sulprofos, tebufenozide, tefluthrin,
terbufos, tetrachlorvinphos, thiodicarb, tralomethrin, trichlorfon
and triflumuron; most preferably a glyphosate compound is
formulated with a fungicide compound or combinations of fungicides,
such as azoxystrobin, benomyl, blasticidin-S, Bordeaux mixture
(tribasic copper sulfate), bromuconazole, captafol, captan,
carbendazim, chloroneb, chlorothalonil, copper oxychloride, copper
salts, cymoxanil, cyproconazole, cyprodinil (CGA 219417),
diclomezine, dicloran, difenoconazole, dimethomorph, diniconazole,
diniconazole-M, dodine, edifenphos, epoxiconazole (BAS 480F),
famoxadone, fenarimol, fenbuconazole, fenpiclonil, fenpropidin,
fenpropimorph, fluazinam, fluquinconazole, flusilazole, flutolanil,
flutriafol, folpet, fosetyl-aluminum, furalaxyl, hexaconazole,
ipconazole, iprobenfos, iprodione, isoprothiolane, kasugamycin,
kresoxim-methyl, mancozeb, maneb, mepronil, metalaxyl, metconazole,
S-methyl 7-benzothiazolecarbothioate (CGA 245704), myclobutanil,
neo-asozin (ferric methanearsonate), oxadixyl, penconazole,
pencycuron, probenazole, prochloraz, propiconazole, pyrifenox,
pyroquilon, quinoxyfen, spiroxamine (KWG4168), sulfur,
tebuconazole, tetraconazole, thiabendazole, thiophanate-methyl,
thiram, triadimefon, triadimenol, tricyclazole, trifloxystrobin,
triticonazole, validamycin and vinclozolin; combinations of
fungicides are common for example, cyproconazole and azoxystrobin,
difenoconazole, and metalaxyl-M, fludioxonil and metalaxyl-M,
mancozeb and metalaxyl-M, copper hydroxide and metalaxyl-M,
cyprodinil and fludioxonil, cyproconazole and propiconazole;
commercially available fungicide formulations for control of Asian
soybean rust disease include, but are not limited to Quadris.RTM.
(Syngenta Corp.), Bravo.RTM. (Syngenta Corp), Echo 720.RTM. (Sipcam
Agro Inc), Headline.RTM. 2.09EC (BASF Corp.), Tilt.RTM. 3.6EC
(Syngenta Corp), PropiMax.TM. 3.6EC (Dow AgroSciences), Bumper.RTM.
41.8EC (Makhteshim-Agan), Folicur.RTM. 3.6F (Bayer CropScience),
Laredo.RTM. 25EC (Dow AgroSciences), Laredo.TM. 25EW (Dow
AgroSciences), Stratego.RTM. 2.08F (Bayer Corp), Domark.TM. 125SL
(Sipcam Agro USA), and Pristine.RTM.38% WDG (BASF Corp) these can
be combined with glyphosate compositions as described in the
present invention to provide enhanced protection from soybean rust
disease; nematocides such as aldoxycarb and fenamiphos;
bactericides such as streptomycin; acaricides such as amitraz,
chinomethionat, chlorobenzilate, cyhexatin, dicofol, dienochlor,
etoxazole, fenazaquin, fenbutatin oxide, fenpropathrin,
fenpyroximate, hexythiazox, propargite, pyridaben and tebufenpyrad;
and biological agents such as Bacillus thuringiensis, Bacillus
thuringiensis delta endotoxin, baculovirus, and entomopathogenic
bacteria, virus and fungi.
[0070] The triazoles and strobilurins are particular effective and
environmental safe fungicides. The mid-seventies saw the
introduction of the fungicide group DMI or demethylation
inhibitors, which contain the triazole fungicides. The triazole
fungicides have been the mainstay of cereal disease control since
then. The first of these to appear was triadimefon (Bayleton) and
there have been new triazoles appearing on a regular basis for
example, popinconazole, tebuconazole, myclobutanil and
epoxiconazole. The triazoles are active against a wide range of
foliar diseases and were used alone or in mixtures with
non-systemic fungicides and also with the systemic morpholine group
of fungicides. Over the twenty-five years since triadimefon was
introduced some of the triazoles have disappeared from the
marketplace as resistance to them developed and they no longer
provided any benefit or advantage to control fungal diseases.
Therefore, the present invention contemplates a triazole type
fungicide alone or in combination with one or more fungicides with
a different mode of action in an admixture with glyphosate. The
mode of action of glyphosate is to inhibit the EPSPS enzyme, a
mixture of glyphosate and a triazole can provide a means to prevent
or reduce the development of resistance to the fungicide by
providing compounds with different modes of action, hence
lengthening the utility of the fungicide for use in crop
production. Both glyphosate and a triazole provide systemic fungal
disease control when applied together or sequentially. The present
invention contemplates a method for reducing fungal resistance to a
triazole fungicide by combining in an admixture a glyphosate
compound and a triazole fungicide compound and treating a
glyphosate tolerant plant with the admixture.
[0071] A new group of fungicides the STAR or strobilurin type
fungicides, were introduced in 1997 with azoxystrobin (Amistar).
This was followed by kresoxim-methyl/epoxiconazole (Allegro) and
trifloxystrobin (Twist) and famoxadone/flusilazole (Charisma),
which is a non-strobilurin but has a strobilurin type action.
Strobilurin type fungicides are based on natural antifungal
compounds, which some forest wood decaying mushrooms secrete to
inhibit competitor fungi. They have a novel mode of action to that
of the other groups of fungicide products. They are also very safe
from an environmental point of view. Various formulations and
fungicide mixtures are commercially available Acanto.RTM. (Syngenta
Corp) is available as a straight strobilurin (picoxystrobin),
Modem.RTM. is another straight strobilurin (pyraclostrobin).
Quadris.RTM. azoxystrobin, Headline.RTM. pyraclostrobin, and
pyraclostrobin plus boscalid are commercially available fungicide
formulations. Straight strobilurins need a non-strobilurin partner
in all situations. Opera (BASF Corp) is a pre-formulated mixture of
pyraclostrobin and epoxiconazole, Stratego.RTM. (Bayer CropScience)
fungicide is a mixture of trifloxystrobin and propiconazole, and
Covershield.RTM. (BASF Corp) is a three-way mixture of
pyraclostrobin, epoxiconazole and kresoxim-methyl. The mode of
action of glyphosate is to systemically inhibit the EPSPS enzyme, a
mixture of glyphosate and a systemic strobilurin type fungicide or
fungicide mixture containing a strobilurin as described, can
provide a means to prevent or reduce fungal disease and development
of fungal resistance to the fungicide, hence lengthening the
utility of the fungicide for crop production. Therefore, the
present invention contemplates a strobilurin type fungicide alone
or in combination with one or more fungicides with a different mode
of action in an admixture with glyphosate. The present invention
contemplates a method for reducing fungal resistance to a
strobilurin fungicide by combining in an admixture a glyphosate
compound and a strobilurin fungicide compound and treating a
glyphosate tolerant plant with the admixture.
[0072] The chloronitriles class of fungicides, for example,
chlorthalonil and chloronil are contact fungicides that are
effective in preventing spore germination and reducing hyphal
growth. It is contemplated that glyphosate in an admixture with a
chloronitrile fungicide will be effective in preventing significant
fungal infection and disease symptoms when applied to glyphosate
tolerant plants. The carboxamides class fungicides, for example,
boscalid, are also contact fungicides for which it is contemplated
that glyphosate in an admixture with a carboxamide fungicide will
be effective in preventing significant fungal infection and disease
symptoms when applied to glyphosate tolerant plants. Contact
fungicides provide a protective effect to plant surfaces to inhibit
spore germination or hyphal growth, the added glyphosate provides
an additional systemic protective effect to inhibit hyphal growth
within the plant tissues.
[0073] The selection of application rates that are effective for a
specific plant pathogen is within the skill of the ordinary
agricultural scientist. Those of skill in the art will likewise
recognize that individual plant conditions, weather and growing
conditions, as well as the specific pathogen and glyphosate
composition selected, will influence the degree of biological
effectiveness achieved in practicing this invention. Useful
application rates for the glyphosate compositions employed can
depend upon all of the above conditions. Preferably, the
application rate will result in a concentration of glyphosate in a
plant tissue of between about 0.01 ppm to about 100 ppm per fresh
weight. More preferable, tissue concentrations of between 0.1 ppm
and 25 ppm glyphosate of fresh weight are obtained in the tissues
of plants treated in the methods of the present invention. Most
preferably, concentrations of between about 0.1 ppm and about 10
ppm or 0.5 ppm and about 10 ppm glyphosate are effective in
controlling, preventing or treating disease in a treated plant.
Table 1 shows glyphosate residue analysis observed in different
glyphosate tolerant crop plants (RR, Round Ready.RTM., registered
trademark of Monsanto Co.) at different application dose rates,
number of treatments (Trt) and developmental stage of the plant
when the glyphosate was applied (R1 in soybean is first flowering,
PH is xxx; in corn V4 and V8 are number of leaves; in cotton OT is
PD is and PH is; in rice lf is leaf, pan ini is panicle initiation
and PH is, in wheat if is leaf, preboot is before the head emerges,
and sugarbeet if is leaf) and the tissues that were analyzed and
the amount of glyphosate detected (Gly (ppm)).
TABLE-US-00001 TABLE 1 Glyphosate residue analysis in glyphosate
tolerant crops Trt tissue Gly (ppm) RR soybean 3 .times. 0.75 lb,
V3/R1/PH forage 7.60 hay 1.30 seed 0.80 RR corn 2 .times. 0.75 lb,
V4/V8 forage 0.73 (GA21) grain 0.07 stover 1.30 RR cotton 3 .times.
1.5 lb, OT/PD/PH seed 1.60 RR canola 0.8 lb seed 0.02 RR rice 1.5
lb 5 lf grain 0.05 straw 0.05 2 .times. 1.12 lb, 5 lf/pan ini grain
3.00 straw 3.10 3 .times. 1.12 lb, 5 lf/pan ini/PH grain 14.80
straw 6.90 RR wheat 0.75 lb, 4 lf forage 2.30 hay 1.20 grain 0.50
straw 0.50 2 .times. 0.75 lb, 4 lf/Preboot forage 2.60 hay 13.00
grain 7.50 straw 5.30 RR sugarbeet 3 .times. 0.75 lb, 2 lf/6 lf/12
lf tops 0.40 beet 0.50 3 .times. 0.75, tops 4.30 2 lf/12 lf/12 lf +
30 d beet 6.60 RR potato 2 .times. 1.5 lb, 2 lf/row closure tubers
4.10 3 .times. 1.5 lb, 2 lf/row clo/PH tubers 8.60
[0074] In one aspect, a rate of application of a composition from
about 0.1 lb/acre to about 5 lb/acre of glyphosate is effective in
controlling, preventing or treating a pathogen in accordance with a
method of the present invention. Yet more preferable are rates of
application ranging from about 0.5 lb/acre to about 2.5 lb/acre.
Most preferable are rates of application of about 0.75 lb/acre.
When glyphosate is used in mixtures with fungicides or as
sequential applications of glyphosate and the fungicide, the rates
may be reduced in order to achieve the most efficient ratio of an
effective concentration of glyphosate and the fungicide to provide
a cost effective disease control mixture. The present invention
demonstrates that application of glyphosate and a fungicide
provides a synergistic benefit. A 1.times. rate of glyphosate (0.75
lb/acre) followed by a 0.5.times. rate of a fungicide compound as
shown in Table 3 in Example 8 will provide equivalent or enhanced
fungal disease control as compared to a 2.times. rate of glyphosate
or a 1.times. rate of a fungicide. It is contemplated that further
reductions in application rates using a glyphosate and fungicide
admixture will be effective to control fungal diseases. For
example, a 1.times. rate of glyphosate mixed with a 0.4.times. rate
of fungicide, or 0.3.times., or 0.2.times., or 0.1.times. rate or
rates in between may be cost effective for the economic control of
fungal diseases. Additionally, a reduced rate of glyphosate in the
mixture may also provide effective and cost efficient control of
fungal diseases, for example, a 0.75.times. rate of glyphosate with
a 0.5.times. rate of a fungicide, or a 0.5.times. rate of
glyphosate with a 0.5.times. rate of fungicide, or a 0.25.times.
rate of glyphosate with a 0.5.times. rate of fungicide, or a
0.1.times. rate of glyphosate with a 0.5.times. rate of fungicide.
A ratio of 0.1.times. glyphosate and 0.1.times. fungicide in an
admixture is contemplated in the present invention, the exact ratio
can be determined by the effective amount of each compound that is
delivered to the diseased or disease susceptible plant tissues and
by those skilled in the art of chemical formulation and application
for the control of fungal diseases of plants.
[0075] Application of glyphosate compositions to foliage of plants
is preferably accomplished by spraying, using any conventional
means for spraying liquids, such as spray nozzles or spinning-disk
atomizers. Compositions of the present invention can be used in
precision farming techniques, in which apparatus is employed to
vary the amount of exogenous chemical substance applied to
different parts of a field, depending on variables such as the
particular plant species present, plant growth stage, soil moisture
status, etc. In one aspect of such techniques, a global positioning
system operated with the spraying apparatus can be used to control
application of the composition in desired amounts to different
parts of a field.
[0076] A glyphosate composition is preferably dilute enough to be
readily sprayed using standard agricultural spray equipment.
Suitable application rates for the present invention vary depending
upon a number of factors, including the type and concentration of
active ingredient and the plant species involved. Useful rates for
applying an aqueous composition to a field of foliage can range
from about 25 to about 1,000 liters per hectare (1/ha), preferably
about 50 to about 300 l/ha, by spray application.
III. Plants
[0077] In one aspect of the present invention, a method is provided
for the application of a glyphosate composition for disease
control, prevention or treatment results in decreased need for
fungicide treatment of plants or plant parts, thus lowering costs
of material, labor, and environmental pollution, or prolonging
shelf-life of products (e.g. fruit, seed, and the like) of such
plants. In a preferred aspect of the method the glyphosate
composition further comprises a fungicide compound. The term
"plant" includes whole plants and parts thereof, including, but not
limited to, shoot vegetative organs/structures (e.g., leaves, stems
and tubers), roots, flowers and floral organs/structures (e.g.,
bracts, sepals, petals, stamens, carpels, anthers and ovules), seed
(including embryo, endosperm, and seed coat) and fruit (the mature
ovary), plant tissue (e.g., vascular tissue, ground tissue, and the
like) and cells (e.g., guard cells, egg cells, and the like), and
progeny of same. The class of plants that can be used in a method
of the invention includes the class of higher and lower plants,
including angiosperms (monocotyledonous and dicotyledonous plants),
gymnosperms, ferns, horsetails, psilophytes, lycophytes,
bryophytes, and multicellular algae. Preferably, plants for use in
the methods of the present invention include any vascular plant,
for example monocotyledons or dicotyledons or gymnosperms,
including, but not limited to alfalfa, apple, Arabidopsis, banana,
barley, canola, castor bean, chrysanthemum, clover, cocoa, coffee,
cotton, cottonseed, corn, crambe, cranberry, cucumber, dendrobium,
dioscorea, eucalyptus, fescue, flax, gladiolus, liliacea, linseed,
millet, muskmelon, mustard, oat, oil palm, oilseed rape, papaya,
peanut, pineapple, ornamental plants, Phaseolus, potato, rapeseed,
rice, rye, ryegrass, safflower, sesame, sorghum, soybean,
sugarbeet, sugarcane, sunflower, strawberry, tobacco, tomato,
turfgrass, wheat and vegetable crops such as lettuce, celery,
broccoli, cauliflower, cucurbits; fruit and nut trees, such as
apple, pear, peach, orange, grapefruit, lemon, lime, almond, pecan,
walnut, hazel; vines, such as grapes, kiwi, hops; fruit shrubs and
brambles, such as raspberry, blackberry, gooseberry; forest trees,
such as ash, pine, fir, maple, oak, chestnut, popular; with
alfalfa, canola, castor bean, corn, cotton, crambe, flax, linseed,
mustard, oil palm, oilseed rape, peanut, potato, rice, safflower,
sesame, soybean, sugarbeet, sunflower, tobacco, tomato, and wheat
preferred. More preferably, plants for use in the methods of the
present invention include any crop plant, for example, forage crop,
oilseed crop, grain crop, fruit crop, vegetable crop, fiber crop,
spice crop, nut crop, turf crop, sugar crop, beverage crop, and
forest crop. In a highly preferred aspect, the crop plant used in a
method is a soybean plant. In another highly preferred aspect, the
crop plant is wheat. In another highly preferred aspect, the crop
plant is corn. In another highly preferred aspect, the crop plant
is cotton. In another highly preferred aspect, the crop plant is
alfalfa. In another highly preferred aspect, the crop plant is
sugarbeet. In another highly preferred aspect, the crop plant is
rice. In another highly preferred aspect, the crop plant is potato.
In another highly preferred aspect, the crop plant is tomato.
[0078] In a preferred aspect, the methods use plants that are
tolerant to glyphosate. Such plants include crop plants that have
been modified to be tolerant of glyphosate. Such plants may be
modified through traditional breeding techniques, or modern
breeding techniques such as genetic engineering. In one preferred
aspect of the present invention, the plants used in the methods are
transgenic plants expressing genes providing tolerance to
glyphosate. Glyphosate tolerance may be imparted to plant species
by recombinant DNA techniques that are described in the art (as
described for example by U.S. Pat. Nos. 5,312,910; 5,310,667;
5,463,175 (all of which are incorporated by reference in their
entirety)). Preferably, glyphosate tolerance is brought about by
inserting a gene encoding a modified or naturally occurring
5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme into the
genome of a plant. A modified EPSPS imparts glyphosate tolerance to
a plant by being less inhibited by glyphosate than is the EPSPS
native to the plant. The source of the gene encoding modified EPSPS
may be a bacterial strain that has naturally developed an EPSPS
resistant to glyphosate, a synthesized double-stranded
deoxyribonucleic acid designed to encode a modified EPSPS, or any
other source.
[0079] For example, a gene for EPSP synthase has been isolated from
Agrobacterium tumefaciens strain CP4, having lower susceptibility
to glyphosate (U.S. Pat. No. 5,633,435 (incorporated by reference
in its entirety)) and when expressed as a transgene in plants
confers a high level of glyphosate tolerance to the plants. In
addition, other EPSPS variants that have lower affinity for
glyphosate and therefore retain their catalytic activity in the
presence of glyphosate have also been described (U.S. Pat. Nos.
4,940,835, and 5,094,945 (both of which are incorporated by
reference in their entirety)). These variants typically have a
higher Ki for glyphosate than the wild-type EPSPS enzyme which
confers the glyphosate tolerant phenotype, but these variants can
also be characterized by a high Km for PEP which makes the enzyme
kinetically less efficient (Kishore and Shah, Ann. Rev. Biochem.
(1988) 57:627-663; Sost et al., FEBS Lett. (1984) 173:238-241;
Shulze et al., Arch. Microbiol. (1984) 137:121-123; Kishore et al.,
Fed. Proc. (1986) 45:1506; Sost and Amrhein, Arch. Biochem.
Biophys. (1990) 282:433-436). Furthermore, high levels of
glyphosate tolerance has been achieved in a number of crop plants
by fusing EPSPS to a chloroplast transit peptide (CTP) for targeted
expression in plastids. Glyphosate tolerance can also be achieved
in plants through inserting into the plant genome a DNA molecule
that causes the production of higher levels of wild-type EPSPS
(Shah et al., Science 233:478-481 (1986). Particularly preferred
methods for achieving glyphosate tolerance in the methods of the
present invention involve genes that allow for the conservation of
glyphosate in the plant tissue that is affected by the plant
pathogen.
[0080] Lines of transgenic glyphosate tolerant crop plants
contemplated for use in the methods of the present invention
include corn, cotton, soybean, sugarbeet, alfalfa, wheat, among
others, that express a gene imparting glyphosate tolerance have
been commercialized or are currently in commercial stages of
development, for example, Roundup Ready.RTM. Cotton 1445 (U.S. Pat.
No. 6,740,488 (incorporated by reference in its entirety)), Roundup
Ready.RTM. corn GA21 and nk603 (U.S. Pat. No. 6,825,400
(incorporated by reference in its entirety)), and Roundup
Ready.RTM. Sugarbeet (U.S. Patent Pub 20040172669A1 (incorporated
by reference in its entirety)), Roundup Ready.RTM. Canola RT73
(US20040018518A1 (incorporated by reference in its entirety)), and
Roundup Ready.RTM. Soybean 40-3-2. Additional Roundup Ready.RTM.
crops underdevelopment by Monsanto Co, St Louis, Mo. include wheat
MON71800 (U.S. Pat. No. 6,689,880 (incorporated by reference in its
entirety)), enhanced Roundup Ready.RTM. cotton 88913 (WO 04/072235
(incorporated by reference in its entirety)), Roundup Ready.RTM.
alfalfa J-101 and J-163 (WO 04/070020 (incorporated by reference in
its entirety)), and ASR368 bentgrass (WO 04/053062 (incorporated by
reference in its entirety)). Production of transgenic lines of
other plant species expressing a glyphosate-tolerance gene may be
produced by techniques known in the art. See, e.g. U.S. Pat. Nos.
5,312,910; 5,310,667; 5,463,175 (all of which are herein
incorporated by reference in their entirety).
[0081] A "transgenic plant" refers to a plant that contains genetic
material not found (i.e. "exogenous") in a wild-type plant of the
same species, variety or cultivar. The genetic material may include
a transgene, an insertional mutagenesis event (such as by
transposon or T-DNA insertional mutagenesis), an activation tagging
sequence, a mutated sequence, a homologous recombination event or a
sequence modified by chimeraplasty. Typically, the foreign genetic
material has been introduced into the plant by human manipulation,
but any method can be used as one of skill in the art
recognizes.
[0082] A transgenic plant may contain an expression vector or
cassette. The expression cassette typically comprises a
polypeptide-encoding sequence operably linked (i.e., under
regulatory control of) to appropriate inducible or constitutive
regulatory sequences that allow for the expression of the
polypeptide. The expression cassette can be introduced into a plant
by transformation or by breeding after transformation of a parent
plant. As previously described a plant refers to a whole plant,
including seedlings and mature plants, as well as to a plant part,
such as seed, fruit, leaf, or root, plant tissue, plant cells or
any other plant material, e.g., a plant explant, as well as to
progeny thereof, and to in vitro systems that mimic biochemical or
cellular components or processes in a cell.
[0083] The plant or plant part for use in the present invention
include plants of any stage of plant development. Preferably, the
application occurs during the stages of germination, seedling
growth, vegetative growth, and reproductive growth. More
preferably, applications of the present invention occur during
vegetative and reproductive growth stages. The stages of vegetative
and reproductive growth are also referred to herein as "adult" or
"mature" plants.
IV. Pathogens
[0084] The methods of the present invention find use in the
control, prevention or treatment of a wide variety of plant
pathogens. The methods of the present invention include
prophylactic inhibition and therapeutic treatment of infection by
plant pathogens. Preferably, the methods of the present invention
inhibit or treat plant pathogenic fungi and bacteria. The plant
pathogens inhibited in the methods of the present invention
preferably include those that produce aromatic amino acids, such as
phenylalanine, tyrosine, and tryptophan, through the shikimate
biosynthetic pathway. Combinations of glyphosate and chemical
inhibitors of enzymes that metabolize glyphosate, metabolize or
oxidize shikimate or 3-phosphoshikimate (for example,
quinate-shikimate dehydrogenase), or prevent plant pathogens from
sequestering glyphosate can function to broaden the spectrum of
plant pathogens that are susceptible to inhibition by glyphosate.
Plant pathogens can be classified by their life cycle in relation
to a plant host, these classifications include, obligatge
parasites, facultative parasites, and facultative saprophytes.
Obligate parasites can only survive and reproduce by obtaining
nutrition from living plant cells and are in direct contact with
these cells, examples of obligate fungal parasites of plants
include, but are not limited to members of Uredinales (rusts),
Ustilaginales (smuts and bunts), Erysiphales (powdery mildews), and
Oomycetes (water molds and downy mildews). Facultative parasites
are organisms that generally survive as saprophytes on the products
of other organisms or dead organisms but can become parasitic when
the conditions are favorable. Facultative saprophytes are organisms
that generally survive as parasites of plants but can survive as
saprophytes when a susceptible plant host is not available.
[0085] The method of the present invention can be used to control,
prevent or treat infection from a wide array of plant pathogens
that include obligate parasites, facultative parasites, and
facultative saprophytes, which include, but are not limited to the
following: Ascomycete fungi such as of the genera Venturia,
Podosphaera, Erysiphe, Monolinia, Mycosphaerella, and Uncinula;
Basidiomycete fungi such as from the genera Hemileia, Rhizoctonia,
and Puccinia; Fungi imperfecti such as the genera Botrytis,
Helminthosporium, Rhynchosporium, Fusarium (i.e., F. monoliforme),
Septoria, Cercospora, Alternaria, Pyricularia, and
Pseudocercosporella (i.e., P. herpotrichoides); Oomycete fungi such
as from the genera Phytophthora (i.e., P. parasitica. P.
medicaginis, P. megasperma), Peronospora (i.e, P. tabacina),
Bremia, Pythium, and Plasmopara; as well as other fungi such as
Scleropthora macrospora, Sclerophthora rayissiae, Sclerospora
graminicola, Peronosclerospora sorghi, Peronosclerospora
philippinensis, Peronosclerospora sacchari and Peronosclerospora
maydis, Physopella zeae, Cercospora zeae-maydis, Colletotrichum
graminicola, Gibberella zeae, Exserohilum turcicum, Kabatiellu
zeae, and Bipolaris maydis; and bacteria such as Pseudomonas
syringae, Pseudomonas tabaci, and Erwinia stewartii; and
mycoplasma, mycoplasma-like, rickettsia and rickettsia-like
organisms, for example Pierce's disease, Alfalfa Dwarf, Phony Peach
disease, Aster Yellows disease, Peach X-disease, corn stunt, and
Peach Yellow disease. Particularly preferred pathogens include, but
are not limited to: Puccinia, Rhizoctonia, GGT, stripe rust, Asian
soybean rust (Phakopsora pachyrhizi), Fusarium species,
Verticillium species, gray leaf spot, Phytophthora species and corn
rust.
[0086] Thus, the diseases controlled, prevented or treated include,
for example, diseases of alfalfa plants such as root rot
(Phytophora medicaginis, P. megasperma); rice plant such as rice
blast (Pyricularia oryzae), Helminthosporium leaf blight
(Helminthosporium oryzae, Cochliobolus miyabeanus), Bakanae disease
(Gibberella fujikuroi), seedling blight (Rhizopus oryzae), sheath
blight (Rhizoctonia solani), and so on, those of oat such as crown
rust (Puccinia coronata), and so on, those of barley such as
powdery mildew (Erysiphe graminis), scald (Rhynchsporium secalis),
spot-blotch (Cochliobolus sativus), yellow mottleleaf
(Helminthosporium gramineum, Pyrenophora gramineum), net blotch
(Pyrenophra teres), stinking smut (Tilletia caries), loose smut
(Ustilago nuda), and so on, those of wheat such as powdery mildew
(Erysiphe graminis), glume-blotch (Leptosphaeria nodorum, Septoria
nodorum), stripe rust (Puccinia striiformis), Typhula snow blight
(Typhula incarnata), eye spot (Pseudocercosporella
herpotrichoides), snow mold (Calonectria graminicola, Fusarium
nivale), stem rust (Puccinia graminis), black snow blight (Typhula
ishikariensis), scab (Gibberella zeae), leaf rust (Puccinia
recondita, Puccinia triticina), stripe (Helminthosporium
gramineum), stinking smut (Tilletia caries), speckled leaf blight
(Septoria tritici), loose smut (Ustilago tritici), and so on, those
of corn such as damping-off (Pythium debaryanum), and so on, those
of rye such as purple snow mold (Fusarium nivale), and so on, those
of potato such as late blight (Phytophthora infestans), and so on,
those of tabacco plant such as downy mildew (Peronospora tabacina),
foot rot (Phytophthora parasitica var), septoria blight (Cercospora
nicotianae), mosaic disease (tobacco mosaic virus), and so on,
those of sugar beet such as leaf spot (Cercospora beticola),
damping-off (Pythium debaryanum, Rhizoctonia solani, Pythium
aphanidermatum), and so on, those of paprika such as gray mold
(Botrytis cinerea), and so on, those of kidney bean such as gray
mold (Botrytis cinerea), sclerotinia seed rot (sclerotial rot)
(Sclerotinia sclerotiorum), southern blight (Corticium rolfsii),
and so on, those of broad bean such as powdery mildew (Erysiphe
polygoni, Sphaerotheca fuliginea), rust (Uromyces fabae, Uromyces
phaseoli), gray mold (Botrytis cinerea), and so on, those of peanut
such as Ascochyta spot (Mycosphaerella arachidicola), and so on,
those of cabbage such as damping blight (Rhizoctonia solani), and
so on, those of cucumber such as powdery mildew (Sphaerotheca
fuliginea), stem rot (Fusarium oxysporum), gummy stem blight
(Mycosphaerella melonis), downy mildew (Pseudoperonospora
cubensis), gray mold (Botrytis cinerea), sclerotial seed rot
(Sclerotinia sclerotiorum), anthracnose (Colletotrichum
lagenarium), damping blight (Fusarium oxysporum, Pythium
aphanidermatum, Rhizoctonia solani), mosaic disease (Cucumber
mosaic virus), and so on, those of KOMATSUNA such as Alternaria
sooty spot (Alternaria brassicicola), club root (Plasmodiophora
brassicae), and so on, those of celery such as speckled leaf blotch
(Septoria apii), and soon, those of radish such as yellows
(Fusarium oxysporum), and so on, those of tomato such as Fusarium
wilt (Fusarium oxysporum), foot rot (Phytophthora infestans), ring
leaf-spot (Alternaria solani), gray mold (Botrytis cinerea), leaf
blight (Phytophthora capsici), black rot (Alternaria tomato), and
so on, those of eggplant such as brown rot (Phytophthora capsici),
vascular wilt pathogens, e.g. Verticillium wilt (Verticillium
albo-atrum. V. dahliae), and so on, those of Chinese cabbage such
as black rot (Alternaria japonica), club root (Plasmodiophora
brassicae), and so on, those of sweet pepper such as foot rot
(Phytophthora capsici), gray mold (Botrytis cinerea), and so on,
those of lettuce such as gray mold (Botrytis cinerea), and so on,
those of citrus fruits such as pod and stem blight (Diaporthe
citri), and so on, those of pear such as scab (Venturia nashicola),
black rot (Alternaria kikuchiana), brown-spot (Gymnosporangium
haraeanum), and so on, those of grape such as downy mildew
(Plasmopara viticola), gray mold (Botrytis cinerea), Sphaceloma
scab (Elsinoe ampelina), and so on, those of peach such as leaf
curl (Taphrina deformans), shot hole (Mycosphaerella cerasella),
and so on, those of apple such as powdery mildew (Podosphaera
leucotria), scab (Cladsporium carpophilum), gray mold (Botrytis
cinerea), black rot (Venturia inaegualis), brown spot
(Gymnosporangium yamadae), white root rot (Rosellinia nectrix),
Alternaria leaf spot (Alternaria mali), and so on, and other
diseases of grains, fruits and vegetables such as oil-seed rape,
sunflower, carrot, pepper, strawberry, melon, kiwi fruit, onion,
leek, sweet potato, fig, ume, asparagus, persimmon, soybean,
adzukibean, watermelon, crown daisy, spinach, tea and so on. Thus,
compound (I.sup.0) or salts thereof show high activities against
diseases caused by microorganisms of, especially, the genus
Pyricularia, Cochliobolus, Curvularia, Pyrenophora, Alternaria, and
others akin to them. Examples of diseases caused by those microbes,
include rice blast, Helminthosporium leaf spot, and discolored rice
grains of rice plant, spot-blotch, stripe, and net blotch of
barley, stripe and spot-blotch of wheat, Helminthosporium leaf spot
of corn, early blight of potato, Alternaria sooty spot of HAKUSAI,
ring leaf-spot and black rot of tomato, black rot of Chinese
cabbage, black rot of pear, and Alternaria leaf spot of apple, and
so on. Not all plant pathogens will be equally susceptible to the
inhibitory effects of the current formulations of glyphosate
compositions. It has been observed in the present invention that
differences exist in the current commercially available
formulations in there effects on plant disease. For example, FIG. 2
compares Roundup WeatherMAX.RTM. (Monsanto Co. St Louis, Mo.) and
Touchdown.TM. IQ (Syngenta Corp) glyphosate formulations, the
results demonstrate that WeatherMAX.RTM. provides superior disease
control over Touchdown.RTM.. WeatherMAX.RTM. has been specifically
formulated to provide rapid uptake of glyphosate into plant
tissues. Plant pathogens that are in contact with plant cells and
tissues (for example, vascular tissue) and exchange chemicals with
the plant cells or tissues will be more effectively suppressed if
the glyphosate applied to the plant is more rapidly absorbed and
translocated to the sites of pathogen infection. It is contemplated
by the inventors that improvements can be made to the current
formulations to provide a glyphosate composition specifically
formulated for use in pathogen control on glyphosate tolerant
plants. Current formulations have been designed for the uptake in
weed species, generally for treatment of weed seedlings and weeds
in a rapid growth stage. It is contemplated that glyphosate
formulations for disease control will be applied to the crop plant
at a later growth stage, for example, when the plant is flowering
or in the process of producing seeds or fruit, it is at these
stages of development that plant diseases can have the greatest
effect on crop yield. Leaves are the source tissues that provide
the products of photosynthesis needed for plant growth, seed, fruit
and storage organ development. Protecting these leaves from disease
due to fungal infection is important to protect yield of the crop.
The flag leaf of monocot crops contributes substantially to the
yield of the crop, protecting this leaf from disease is
particularly important in protecting monocot crop yield. Leaves of
dicot crops generally provide the products of photosynthesis to the
closely associated fruiting structures of the plant, protecting
these leaves from disease is particularly important in protecting
dicot crop yields. Roots provide water and mineral nutrients to the
plants, protecting roots from disease is also particularly
important in maintaining yield of the crop plant. Enhanced
formulations for systemic (includes both locally systemic and whole
plant systemic) uptake may include the addition of adjuvants, for
example, alkoxylated fatty amines, organosilicones, nonyl phenol
ethylene oxide condensate, and others known in the art. Examples of
suitable adjuvants that enhance the uptake and efficacy of
glyphosate include polyoxyalkylene alkylamines, polyoxyalkylene
alkylammonium salts, polyoxyalkylene alkylamine oxides,
polyoxyalkylene tertiary and quaternary etheramines,
polyoxyalkylene etheramine oxides, mono- and di-(polyoxyalkylene
alcohol) phosphates, polyoxyalkylene alkylethers and combinations
thereof. Preferred adjuvants are polyoxyethylene coco and tallow
amines, polyoxyethylene C.sub.8-18 alkyl oxypropyl amines,
polyoxyethylene C.sub.16-22 alkylethers and combinations thereof.
Examples of these adjuvants can be found in U.S. Pat. Nos.
5,668,085, 5,683,958, 5,703,015, 6,063,733, 6,121,199, 6,121,200,
6,184,182, 6,245,713, 6,365,551, RE37,866 and U.S. Patent
Application Pub. No. US2003/0104943 A1 (all of which are herein
incorporated by reference in their entirety).
[0087] It is further contemplated that glyphosate formulations with
combinations of surfactants that provide greater contact with the
plant pathogen on a leaf surface by retaining and spreading the
glyphosate onto the leaf surface will also enhance the glyphosate
effect on the pathogen. These formulations provide surfactants for
the spread of the glyphosate composition across the leaf surface
and enhance the contact and uptake of glyphosate into a fungal
spore or hyphae, so that when a pathogen contacts a leaf surface so
treated, it will also contact the glyphosate. Additionally,
surfactants used in contact fungicides may enhance the uptake of
glyphosate into the fungal cell when the formulation is in contact
with a fungal spore or hyphae.
[0088] Disease resistance evaluation can be performed by methods
known in the art. See, Uknes et al, (1993) Molecular Plant Microbe
Interactions 6: 680-685; Gorlach et al., (1996) Plant Cell
8:629-643; Alexander et al., Proc. Natl. Acad. Sci. USA 90:
7327-7331 (1993). The skilled artisan will recognize that methods
for determining plant infection and disease by a plant pathogen
depends on the pathogen and plant being tested.
[0089] The following examples are included to demonstrate aspects
of the invention. It should be appreciated by those of skill in the
art that the techniques disclosed in the examples which follow
represent techniques discovered by the inventors to function well
in the practice of the invention, and thus can be considered to
constitute preferred modes for its practice. However, those of
skill in the art should, in light of the present disclosure,
appreciate that many changes can be made in the specific aspects
which are disclosed and still obtain a like or similar result
without departing from the spirit and scope of the invention.
EXAMPLES
Example 1: In Vitro Effects of Glyphosate on Plant Pathogens
[0090] In vitro screens identified glyphosate as a very weak
fungicide against a series of pathogenic organisms. Table 2 shows
that when various fungal plant pathogens are grown on growth media
containing various concentrations of glyphosate to measure
EC.sub.90 concentrations (the concentration for 90% of maximal
effect of, e.g., inhibiting fungal cell proliferation or
statistically reducing the level fungal growth). These data
demonstrate a high concentration of glyphosate is required to
inhibit fungal growth in vitro. It was therefore a surprising
result when it was observed that glyphosate tolerant plants when
treated with glyphosate showed resistance to fungal disease. The
glyphosate residue analysis shown in Table 1 would have suggested
that the levels of glyphosate in the plant tissues to be too low
for effective inhibition of fungal pathogens. The susceptibility of
fungal pathogens to glyphosate effects may change when the pathogen
is in contact with plant cells. The chemical exchange that occurs
between a fungal pathogen and the host plant cell allows for the
importation of glyphosate into the fungal cell that is not evident
in an in vitro assay.
TABLE-US-00002 TABLE 2 In vitro effects of glyphosate on fungal
cell growth Fungus In vitro EC.sub.90, ppm Crop of interest
Septoria <100 Wheat Pseudocercosporella <100 Wheat Botrytis
<100 Veg/strawberry Phytophthora 1000 Potato/soy Rhizoctonia
1000 Wheat/potato Fusarium 1000 Wheat/potato Gaeumannomyces 1000
Wheat Puccinia 5000 Wheat Pyricularia 5000 Rice
Example 2: Disease Treatment in Glyphosate Tolerant Wheat
[0091] Compositions of water, surfactant (a 0.1% solution),
glyphosate formulations (WeatherMAX.RTM. (glyphosate-K salt),
UltraMAX.RTM. (glyphosate-IPA salt), or a glyphosate composition
without surfactant (IPA-salt) are applied to glyphosate tolerant
wheat plants at different growth stages that have been previously
inoculated with leaf rust (Puccinia triticina) to test for disease
control. Three, five and seven-leaf stage wheat plants are
inoculated with Puccinia triticina spores and incubated to allow
for spore germination.
[0092] Plants are evaluated for disease at one day after treatment
(1DAT) with the above compositions. In addition, wheat plants at
the 5 leaf stage are used as an untreated control.
[0093] All eleven (11) untreated wheat plants exhibited significant
leaf rust symptoms. Seven out of eight water-treated wheat plants
(3-leaf stage) showed disease symptoms. Similarly,
surfactant-treated plants at the 3 leaf and 7 leaf stages exhibited
nearly complete disease infection. Six out of eight 3-leaf stage
wheat plants showed disease symptoms at 1DAT, while all four 7-leaf
stage wheat plants showed disease symptoms.
[0094] In contrast, plants treated with glyphosate compositions
demonstrated substantially total disease control. Disease treatment
was achieved using an application rate of 1.times. (equals 0.75
lb/acre through the 5.sup.th leaf). In wheat plants at the 5-leaf
stage treated with a 1.times. glyphosate composition (Roundup
WeatherMAX.RTM. formulation), none of the 11 treated plants showed
disease symptoms. In 3-leaf stage plants, none of the 8 inoculated
plants showed disease symptoms and none of the 4 inoculated 7-leaf
stage plants showed signs of infection after treatment with a
1.times. Roundup WeatherMAX application.
[0095] These results demonstrate that glyphosate compositions can
be used to treat fungal infection, such as leaf rust, in
glyphosate-tolerant wheat plants.
Example 3: Correlation of Tissue Glyphosate Concentration and
Disease Prevention
[0096] To determine the correlation between glyphosate
concentration in plant tissue and disease control, glyphosate
tolerant wheat plants are treated with glyphosate compositions
prior to inoculation with Puccinia spores. Four different regimens
are employed. First, whole plants, either 3-leaf or 5-leaf stage,
are treated with a 1.times. spray of WeatherMAX Roundup.RTM.
glyphosate composition. A single mature leaf from each treated
plant is inoculated with Puccinia spores either 1 day or 14 days
after glyphosate application. The inoculated plants are then
incubated for 24 hours at 100% relative humidity for germination of
the spores. Twelve days after inoculation, disease conditions are
evaluated and concentrations of glyphosate in the plant tissue is
quantitated. Disease conditions are evaluated macroscopically for
pustule development and lesion development.
[0097] Disease symptoms were prevented in inoculations both at 1
day after glyphosate treatment and 14 days after treatment. FIG. 1
shows that control plants not treated with glyphosate demonstrated
about 25% to about 30% pustule development 12 days after
inoculation. In contrast, plants treated with glyphosate showed
less than 1% pustule development 12 days after inoculation.
[0098] Furthermore, disease prevention directly correlates with
tissue glyphosate concentrations. For example, lesion and pustule
development are prevented at tissue concentrations of glyphosate of
20 to 80 ppm, while pustule development is prevented by as low as
about 10 ppm glyphosate. Autoradiograms of leaves treated with
14C-glyphosate confirmed that glyphosate concentrations are
uniformly distributed throughout the inoculated leaf.
Example 4: Comparison of Roundup.RTM. WeatherMAX Formulation to
Touchdown.TM. IQ Formulation
[0099] Various formulations of glyphosate are commercially
available. The inventors contemplated that these formulations may
vary in their ability to affect fungal disease development. The
results of a comparison of WeatherMAX.RTM. and Touchdown.TM. IQ
performed on Roundup Ready wheat to control wheat leaf rust either
as a preventative or curative application is shown in FIG. 2. The
rates of the formulation applications were from 1/8.times. to
1.times.. The treatments were at one day after inoculation with
rust spores (1DAI) or three days after inoculation (3DAI). Rust
disease was measured 10 days after inoculation by determining the
percent leaf infection. Both formulations demonstrated the ability
to reduce percent leaf infection, with the WeatherMAX.RTM.
formulation providing a greater benefit than the Touchdown.TM.
formulation a lower dose rates. The present invention provides for
the use of WeatherMAX.RTM. formulation and effective application
rates thereof for the treatment of fungal disease on glyphosate
tolerant plants. Additional glyphosate formulations are
contemplated that provide enhanced uptake in glyphosate tolerant
plants or enhanced uptake in plant pathogens, in particular fungal
pathogens.
Example 5: Translocation of Glyphosate for Disease Prevention
[0100] 14C-glyphosate is sprayed over-the-top to wheat plants using
field application conditions and use rates. The top fully-expanded
leaf (one leaf) is shielded from the spray (the untreated leaf).
The untreated leaf is manually infected with Puccinia spores one
day after treatment (1DAT) with glyphosate to generate leaf
rust.
[0101] Analysis at 11 days after inoculation (DAI) with Puccinia
show a decrease in disease incidence with an increase in spray
dose. Analysis of glyphosate in the shielded leaf show a decrease
in disease with an increase in tissue glyphosate at 0 or 11 DAI.
Complete disease prevention was attained at 1.3 ppm glyphosate from
spray application of 1/2.times. of Roundup.RTM.. Since the
untreated leaf is shielded from the spray, glyphosate in tissues
arose strictly from phloem translocation. The results indicate that
phloem-mobilized glyphosate is associated with the observed disease
prevention and the rust pathogen obtained the glyphosate from
contact with plant tissue containing the systemically translocated
glyphosate.
Example 6: Systemic Acquired Resistance
[0102] To test whether disease control, prevention or treatment
correlates with the induction of Systemic Acquired Resistance (SAR)
time-course Northern blot analysis are conducted as described
herein.
[0103] Glyphosate tolerant wheat plants (3-4 leaf stage) are
separated into three (3) groups and sprayed with one of the
following compositions: a 0.1% surfactant blank from Roundup.RTM.
(WeatherMAX), Roundup.RTM. WeatherMAX (0.751b/acre), or INA
(2,6-dichloro isonicotinic acid, 200 ppm in 0.1% surfactant blank).
One-half of the plants from each of the three treatments are
sampled from 0 to 144 hours after treatment for induction of SAR
genes.
[0104] The remaining treated plants are inoculated with leaf rust
spores (Puccinia triticina) one day after treatment with one of the
three compositions. The inoculated plants are incubated in a dew
chamber for 24 hours. Leaf tissues from the inoculated plants are
collected at time points from 0 to 120 hours after inoculation.
[0105] Leaf tissue from each sampling is homogenized and total RNA
is isolated following standard methods. The total RNA is separated
on an Agarose gel, and transferred to nitrocellulose membrane for
use in Northern hybridizations. The membranes containing the
separated total RNA are hybridized with radiolabeled representative
SAR genes, WIR2 (PR5) and WCI3.
[0106] Northern blot analysis revealed that the PR5 gene is induced
in leaf tissues of all 3 treatments as well as spore inoculation.
However, plants treated with Roundup WeatherMAX.RTM. are the only
plants lacking infection. Northern results indicated that induction
of the PR5 induction gene did not correlate with disease control,
and therefore is not responsible for leaf rust resistance. The WCI3
gene is induced by INA treatment but also did not confer leaf rust
resistance. The Northern results indicate that induction of the
tested SAR genes does not correlate with resistance to leaf rust in
RR wheat.
Example 7: Glyphosate as a Post-Infection Treatment
[0107] To determine if glyphosate could treat disease
post-infection, one top leaf of glyphosate tolerant wheat plants
(3-leaf stage) is inoculated with rust spores. Depending on the
treatment to be used, the spores are then allowed to germinate.
Seven treatments are employed: 1) no treatment, 2) surfactant
treatment before spore inoculation, 3) surfactant after spore
inoculation, but before spore germination, 4) 1.times. glyphosate
after inoculation before germination, 5) 1.times. glyphosate after
germination (0 days after inoculation (DAD), 6) 1.times. glyphosate
at 1DAI, and 7) 1.times. glyphosate at 4DAI (lesions were already
present). Disease incidence is evaluated 11 DAI. Plants left
untreated or treated only with surfactant show infection levels of
between 10% and about 25%, FIG. 1. In contrast, plants treated with
glyphosate show either no infection or no progression to an
existing infection. For example, the plants treated with 1.times.
glyphosate at 4DAI in which lesions are already present at the time
of treatment showed no development of pustules. In contrast,
untreated plants show substantial development of pustules. These
results indicate that glyphosate compositions can be used to treat
fungal infections in plants.
Example 8: Glyphosate to Control, Prevent or Treat Soybean Rust
[0108] Asian soybean rust is an aggressive foliar disease of
soybean that occurs where soybeans are grown in Asia, and more
recently, in southern Africa, Paraguay, Argentina and Brazil.
Phakopsora pachyrhizi, the fungus that causes Asian soybean rust,
has been found in the continental United States. Glyphosate
compositions are used to control, prevent or treat disease in
glyphosate tolerant soybean plants (RR) under field conditions. A
single application rate of Roundup.RTM. (1.times.=0.75 lbs ae/acre
or 0.84 kg ae/ha) or multiple applications are applied times to a
rust susceptible variety of soybean. The Roundup.RTM. treated
plants are not treated with any fungicide and allowed to be
naturally infected with Asian soybean rust. In addition,
glyphosate-tolerant soybean plants can be grown in a greenhouse and
manually infected with spores to induced disease infection.
[0109] The treated and untreated plants are observed for disease
incidence and results obtained for using glyphosate compositions in
glyphosate tolerant soybean plants to control, prevent or treat
rust. Rust development is delayed 7-10 days in RR soybean (sprayed
at .about.V4 stage), as compared to conventional soy. Rust severity
is less in RR soybean as compared to conventional soybean in early
season observations. This effect was observed in multiple RR
soybean varieties, and at multiple field locations in Brazil.
Frequent low to moderate rates of glyphosate treatment during the
growing season provides a decrease in disease incidence of Asian
soybean rust.
[0110] A study was conducted in a greenhouse in Brazil to confirm
the earlier field observations and to test for the effects of
combining a glyphosate and a fungicide treatment. Two Roundup
Ready.RTM. soybean cultivars, RR8000 and RR8045 that contain the
40-3-2 transgene insert were treated with glyphosate and a
fungicide (Opera). The treatments (trt) were Treatment 1--no
glyphosate spray and no Opera fungicide, Treatment 2--1.times.
glyphosate, no Opera fungicide applied every two weeks starting at
V3 (V3=third vegetative leaf) until final disease rating; Treatment
3--2.times. glyphosate, no Opera fungicide every two weeks starting
at V3 until final disease rating;
[0111] Treatment 4--no glyphosate, 1.times. Opera according to
manufacturer's label, every two weeks starting at V3 until final
disease rating; Treatment 5--no glyphosate, 0.5.times. Opera, every
two weeks starting at V3 until final disease rating; Treatment
6--1.times. glyphosate, 0.5.times. Opera sequential sprays, every
two weeks starting at V3 until final disease rating. The results
are shown in Table 3. The plants of the RR8000 and RR8045 cultivars
with treatment 1, no spray treatment, showed rust disease of 81.7
and 93.3 percent, respectively. The treatment 2, 1.times.
glyphosate treatment, demonstrated a reduction in the percent rust
disease up to the 56 day time point; treatment 3, 2.times.
glyphosate, showed a high level of disease reduction at the first
three time points for RR8000 and RR8045, increasing to 30.0 percent
and 73.3 percent at the 56 day time point. Treatment 4, Opera
1.times., showed a high level of disease reduction in both
cultivars at all time points. Treatment 5, Opera 0.5.times., showed
a high level of disease control for the first two time points, then
increasing to 30.0 and 33.3 at the 56 day time point. Treatment 6,
1.times. glyphosate plus 0.5.times. Opera, showed a high level of
disease control, especially at the 42 and 56 day time points. These
results demonstrate that glyphosate treatment controls soybean rust
disease in glyphosate tolerant soybean and the effect is
synergistic when combined with a fungicide treatment.
TABLE-US-00003 TABLE 3 Greenhouse study of Glyphosate (glyp) and
Opera fungicide effects on the percent disease of Asian soybean
rust on two treated Roundup Ready soybean cultivars. RR 14 d-1 28
d-2 42 d-3 56 d-4 cultivars spray sprays sprays sprays RR8000 Trt 1
No spray 40.0 56.7 71.7 81.7 Trt 2 glyp 1X 23.3 41.7 48.3 88.3 Trt
3 glyp 2X 10.0 10.0 10.0 30.0 Trt 4 Opera 1X 3.3 3.3 6.7 13.3 Trt 5
Opera .5X 10.0 10.0 23.3 30.0 Trt 6 glyp1X + O.5X 10.0 10.0 10.0
13.3 RR8045 Trt 1 No spray 56.7 71.7 81.7 93.3 Trt 2 glyp 1X 50.0
56.7 71.7 86.7 Trt 3 glyp 2X 3.3 10.0 13.3 73.3 Trt 4 Opera 1X 6.7
10.0 16.7 16.7 Trt 5 Opera .5X 10.0 13.3 26.7 33.3 Trt 6 glyp1X +
O.5X 3.3 10.0 13.3 13.3
[0112] A field study was conducted to further confirm the
greenhouse study. The same cultivars were planted in three
replicated plots and treatments as described in the greenhouse
study. Table 4 shows the result of the field study demonstrating
that glyphosate treatment substantially reduces the percent disease
due to Asian soybean rust infection. Glyphosate+fungicide treatment
of RR8000 showed a synergistic effect (13.3%) in reducing disease
when compared to the glyphosate 1.times. rate (23.3%) and Opera
0.5.times. (21.7%) rate treatments. All treatments were effective
in preventing disease on RR8045 cultivar. These results provide
further evidence that glyphosate is useful to control Asian soybean
rust disease in glyphosate tolerant soybeans in a field environment
and that an admixture of glyphosate and a fungicide is particularly
effective.
[0113] Roundup WeatherMAX.RTM. (WMAX) tank mixes with fungicides,
insecticides or both are tested for use in soybean. Soybean rust is
a significant problem disease in South America and serious concern
in the U.S. Testing is conducted to develop a method for use of
mixtures of the WMAX formulation of glyphosate and various
commercially available fungicides for weed control and soy rust
control as listed in Table 5. The fields are planted with Roundup
Ready.RTM. soybeans after use of tillage or Roundup WMAX to reduce
weeds. All plots receive a post plant application of Roundup WMAX
about 3 weeks after planting. The mixtures of WMAX alone or
WMAX+fungicide are used to treat the plots at the R1 stage of
soybean development (first flowering) of treatment are listed in
Table 5. Data is taken for percent weed control at 7 and 21 days
after R1 treatment, soybean safety (% necrosis, chlorosis, growth
rate): 5 days after treatment, disease rating, and soybean yield
(bushels/Acre). These mixtures and treatments are designed to
provide simultaneous weed and pest control of soybean, such as
fungal pest control, for example, soybean rust disease; and insect
pest control, for example, aphid control.
TABLE-US-00004 TABLE 5 Glyphosate plus pesticide mixtures
(fungicides and an insecticide) mix R1, flowering 14 to 21 days
after R1 1 WMAX 2 WMAX 3 WMAX + Quadris .RTM. 4 WMAX + Bravo .RTM.
5 WMAX + Stratego .RTM. 6 WMAX + Tilt .RTM. 7 WMAX + Folicur .RTM.
8 WMAX + Headline .RTM. 9 WMAX + Quadris .RTM. 10 WMAX + Bravo
.RTM. 11 WMAX + Stratego .RTM. 12 WMAX + Tilt .RTM. 13 WMAX +
Folicur .RTM. 14 WMAX + Headline .RTM. 15 WMAX + Warrior .RTM. +
Quadris .RTM. 16 WMAX + Warrior .RTM.
[0114] Agricultural chemicals are provided in containers suitable
for safe storage, transportation and distribution, stability of the
chemical compositions, mixing with solvents and instructions for
use. The present invention provides for a container of a mixture of
a glyphosate compound and a fungicide compound, or a mixture of a
glyphosate compound and an insecticide compound, or a mixture of a
glyphosate compound and a fungicide compound and an insecticide
compound (Warrier.RTM.). The container may further provide
instructions on the effective use of the mixture. Containers of the
present invention can be of any material that is suitable for the
storage of the chemical mixture. Containers of the present
invention can be of any material that is suitable for the shipment
of the chemical mixture. The material can be of cardboard, plastic,
metal, or a composite of these materials. The container can have a
volume of 0.5 liter, 1 liter, 2 liter, 3-5 liter, 5-10 liter, 10-20
liter, 20-50 liter or more depending upon the need. A tank mix of a
glyphosate compound and a fungicide compound is provided, methods
of application to the crop to achieve an effective dose of each
compound are known to those skilled in the art and can be refined
and further developed depending on the crop, weather conditions,
and application equipment used.
Example 9: Glyphosate to Prevent or Control Rust of Corn
[0115] Puccinia sorghi is the fungus causing Common rust disease in
corn and Southern rust disease is caused by the fungus Puccinia
polysora. Field tests were conducted to determine if glyphosate
treatment of Roundup Ready.RTM. corn nk603 hybrid and inbred lines
could reduce the incidence of disease caused by rust diseases of
corn. The glyphosate tolerant corn plants and non-tolerant control
plants were inoculated with Common rust or Southern rust
spores.
[0116] The glyphosate was applied as a formulation of Roundup.RTM.
WeatherMAX.RTM. (4.5 lbs./Gal, 49% a.i.) from a CO2 backpack
sprayer with a 2-nozzle boom (8002 nozzle) at 30 pounds per square
inch. The treatment was pre-inoculation (treatment #1,
approximately 5 hours before the inoculation of the rust spores),
14 days post inoculation (treatment #2), and 28 days post
inoculation (treatment #3). Glyphosate was applied at a 2.times.
rate (1.5 lb./A) and a 3.times. rate (2.25 lb./A) at each treatment
time. Two hybrid corn lines (DKC53-33 and DKC60-09) and two inbred
corn lines ((87DIA4NK603A and 90DJD28NK603A) were tested in the
experimental plots. The plot size was 2 rows at 10 replications=20
rows per treatment at 2.5 ft/per row=50 ft. wide at 15 ft.
length=750 sq. ft./43,560 sq. ft./Acre=0.0172 Acres/Treatment.
Disease ratings were taken on a 1 to 9 scale where 1=resistant and
9=susceptible. The rating used in the analysis is the average of
the last three rating dates (approximated 5 weeks post inoculation,
7 weeks post inoculation and 9 weeks post inoculation).
[0117] The results of the hybrid corn test showed the control plots
with an average disease rating of 4.1 for each line and treatment
#1 at the 2.times. rate with an average disease rating of 3.6 and a
disease rating of 3.0 at the 3.times. rate. Treatment #2 and #3 had
a disease rating of 4.1 and 3.9 respectively. The inbred corn test
showed the control plots with an average disease rating of 5.0 and
4.9 for each line and treatment #1 with an average disease rating
of 4.0 at the 2.times. rate and 3.2 for the 3.times. rate. The post
inoculation treatments showed a disease rating of 4.4 and 4.9.
[0118] Natural Common rust infection occurred prior to the
artificial inoculations in these tests, therefore the controls
(uninoculated/unsprayed, and inoculated/unsprayed) showed about the
same disease rating. These results demonstrated that glyphosate
treatment reduces disease severity of corn rusts, especially when
applied early in the infection process.
Example 10: Verticillium Wilt Control in Roundup Ready.RTM.
Cotton
[0119] Verticillium wilt is a soil borne fungal vascular wilt
pathogen that attacks over 300 woody and herbaceous host plants.
Especially important are members of the Solanaceous plant family,
for example, tomato, potato, and eggplant. Other crops of
importance are alfalfa, sunflower, peanuts, and cotton.
Verticillium dahliae is the causal organism for Verticillium wilt
of cotton.
[0120] The ability of glyphosate to provide reduction in disease
symptoms of Verticillium wilt of cotton was tested with Roundup
Ready.RTM. cotton in three genetic backgrounds. The cotton seeds
were planted and the emerged plants were sprayed with 22 ounces of
WeatherMax Roundup.RTM. at the two and five true leaf stage. Plants
were observed for wilt symptoms approximately three months and four
months after planting. The glyphosate treated plants showed reduced
symptoms and were more vigorous than the plants in the adjacent
untreated plot. The treated plants continued to grow compared to
the untreated plants that had shut down. The observation indicates
that moderately Verticillium resistant and susceptible cotton lines
with glyphosate tolerant genetic backgrounds with benefit from
glyphosate treatment to reduce the severity of Verticillium wilt
disease. Cotton plants suffering from other wilt diseases of
cotton, especially Fusarium wilt disease, are expected to benefit
from treatment with glyphosate.
Example 11
[0121] Plant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS)
enzymes are very sensitive to glyphosate and kinetic studies have
shown that corn EPSPS has a Ki for glyphosate of 0.5 .mu.M, which
is equivalent to approximately 0.15 ppm of glyphosate in plant
tissues. Structural studies of EPSPS based on X-ray crystallography
have identified key amino acids involved in catalysis. These amino
acids are highly conserved across species and have been used to
characterize the interactions between glyphosate and EPSPS. In
fact, the presence of 4 unique amino acid motifs has been used to
classify the EPSPS enzymes into glyphosate sensitive or resistant
variants (U.S. Pat. No. 5,633,435). A search of public databases
showed genomic sequences from twelve fungi shown in Table 6. We
deduced and aligned the amino acid sequences of the fungal EPSPSs
and conclude that all twelve are classified as glyphosate
sensitive. The presence of a glyphosate-sensitive EPSPS is
necessary for glyphosate to have activity against a fungal pest,
although other processes present in the fungal pest cell could
influence the level of effect that glyphosate would have, such as,
the presence of a glyphosate metabolism process, or glyphosate
transport, or sequestering process. The result of our analysis
indicates that fungi are likely to posses a glyphosate-sensitive
EPSPS, which would translate to inhibition or suppression of fungal
cell growth and development when treated with a glyphosate
composition.
TABLE-US-00005 TABLE 6 EPSPS gene id Fungus Genus species name
gi|6320332 Saccharomyces cerevisiae gi|45201161 Eremothecium
gossypii gi|46444923 Candida albicans SC5314 gi|19115593
Schizosaccharomyces pombe gi|6226554 Aspergillus nidulans
gi|44889967 Aspergillus fumigatus gi|38102656 Magnaporthe grisea
70-15 gi|32415183 Neurospora crassa gi|46116890 Gibberella zeae
PH-1 gi|49074134 Ustilago maydis 521 gi|25005077 Thanatephorus
cucumeris gi|2492977 Pneumocystis carinii gi|31087950 Puccinia
triticina
[0122] All publications, patents and patent applications are herein
incorporated by reference to the same extent as if each individual
publication or patent application was specifically and individually
indicated to be incorporated by reference.
* * * * *