U.S. patent number PP32,460 [Application Number 16/602,126] was granted by the patent office on 2020-11-17 for corylus plant named `raritan`.
This patent grant is currently assigned to Rutgers, The State University of New Jersey. The grantee listed for this patent is RUTGERS, THE STATE UNIVERSITY OF NEW JERSEY. Invention is credited to John M. Capik, Shawn A. Mehlenbacher, Thomas J. Molnar.
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United States Patent |
PP32,460 |
Molnar , et al. |
November 17, 2020 |
Corylus plant named `Raritan`
Abstract
A new and distinct Corylus avellana plant named `Raritan`
characterized by a vigorous and upright-spreading growth habit, the
production of nuts with round kernels that fall free of the husk at
maturity, and a high level of tolerance (quantitative resistance)
to eastern filbert blight caused by the fungus Anisogramma anomala
(Peck) E. Muller.
Inventors: |
Molnar; Thomas J. (East
Brunswick, NJ), Mehlenbacher; Shawn A. (Corvallis, OR),
Capik; John M. (Somerset, NJ) |
Applicant: |
Name |
City |
State |
Country |
Type |
RUTGERS, THE STATE UNIVERSITY OF NEW JERSEY |
New Brunswick |
NJ |
US |
|
|
Assignee: |
Rutgers, The State University of
New Jersey (New Brunswick, NJ)
|
Family
ID: |
73263780 |
Appl.
No.: |
16/602,126 |
Filed: |
August 12, 2019 |
Current U.S.
Class: |
PLT/152 |
Current CPC
Class: |
A01H
5/08 (20130101); A01H 5/12 (20130101); A01H
6/00 (20180501) |
Current International
Class: |
A01H
5/08 (20180101); A01H 6/00 (20180101) |
Field of
Search: |
;PLT/152 |
Other References
http://thescalepit.com/ContentHN/Hazel%20Dormancy%20and%20Pollination.pdf;
Apr. 8, 2019; 9 pages. cited by examiner.
|
Primary Examiner: Bell; Kent L
Attorney, Agent or Firm: Daugherty; Patrick J. Daugherty
& Del Zoppo Co., LPA
Claims
What is claimed is:
1. A new and distinct cultivar of Corylus plant named `Raritan`, as
illustrated and described.
Description
Latin name: Corylus avellana cultivar.
Variety denomination: `Raritan`.
BACKGROUND OF THE INVENTION
The present invention relates to a new and distinct cultivar of
Corylus plant, botanically known as Corylus avellana and the
designation `Raritan`, or as `Raritan` Hazelnut (H3FR03P33 Rutgers
1), and hereinafter referred to by the name `Raritan`. The new
Corylus resulted from a controlled cross of the female parent OSU
539.031 (unpatented, unreleased breeding selection) with pollen of
OSU 616.018 (unpatented, unreleased breeding selection) made in
2004. Hybrid seeds resulting from the cross were harvested in
August 2004. They were provided a period of moist chilling,
subsequently germinated, and the seedlings were grown in the
greenhouse during the summer of 2005. From this cross, a total of
92 seedling trees were planted in a research field in East
Brunswick, N.J., in October 2005. `Raritan` was discovered and
selected as a single plant within that progeny of the stated
cross-pollination. It was originally assigned the designation
H3FR03P33, which indicates the field, row, and tree location of the
original seedling.
The female parent OSU 539.031 is an unpatented, unreleased seeding.
The male parent OSU 616.018 is also an unpatented, unreleased
seedling . Both parents of `Raritan` express a high level of
tolerance (quantitative/horizontal resistance) to eastern filbert
blight caused by the fungus Anisogramma anomala (Peck) E.
Muller.
The new cultivar was asexually reproduced by rooted suckers and
whip grafting in 2010 through 2015 in East Brunswick and New
Brunswick, N.J. The unique features of this new Corylus are stable
and reproduced true-to-type in successive generations of asexual
reproduction.
BRIEF SUMMARY OF THE INVENTION
The following traits have been observed and are determined to be
the unique characteristics of `Raritan`. These characteristics in
combination distinguish `Raritan` as a distinct cultivar:
Vigorous and upright-spreading plant habit.
Yellowish-green to green color of developing and fully expanded
leaves during the spring and summer.
High level of tolerance (quantitative resistance/horizontal
resistance) to eastern filbert blight (EFB) caused by the fungus
Anisogramma anomala (Peck) E. Muller. The source of this resistance
differs from the single dominant allele conferred from `Gasaway`
(unpatented, Mehlenbacher et al., 1991), which protects Corylus
avellana `McDonald` (U.S. Plant Pat. No. 28,200P3, Mehlenbacher et
al., 2016), `Wepster` (U.S. Plant Pat. No. 27,141P3, Mehlenbacher
et al., 2014), `Dorris` (U.S. Plant Pat. No. 25,022P3, Mehlenbacher
et al., 2013), `Jefferson` (unpatented, Mehlenbacher et al.,
2011a), `Yamhill` (unpatented, Mehlenbacher et al., 2009), and
several other Corylus avellana cultivars and pollenizers known to
the Inventors.
Expression of incompatibility alleles S3 and S22 in the styles.
Comparisons in several replicated plantings in East Brunswick,
N.J., show that plants of `Raritan` differed from plants of the
Corylus avellana cultivar `Barcelona` (unpatented), `Tonda di
Giffoni` (unpatented), `Yamhill`, `Jefferson`, and other cultivars
and selections of Corylus avellana known to the Inventors,
primarily in their response to eastern filbert blight present in
New Jersey, a region where the pathogen is native and highly
genetically diverse (Muehlbauer et al., 2019). They also differed
in S-alleles, nut size, nut shape, kernel percentage (ratio of
kernel weight to nut weight), frequency of defects (blank nuts,
moldy kernels, twin kernels, etc.), time of pollen shed, and length
of the husk or involucre.
`Raritan` is immediately distinguished from its parents by its
incompatibility allele (S-allele) combinations. `Raritan` expresses
S-alleles S3 and S22 in its stigmas whereas OSU 539.031 expresses
S2 and S22 and OSU 616.018 expresses S2 and S3. `Raritan` also
differs in its response to the disease eastern filbert blight (EFB)
caused by Anisogramma anomala. Both OSU 539.031 and OSU 616.018
express a moderate level of tolerance to EFB similar to that
reported for `Sacajawea` for average proportion of diseased wood,
which was shown to be 21.0% (calculated by total length of
EFB-diseased stems per tree divided by total length of shoot
growth) (see [0142] Capik, J. M. and T. J. Molnar. 2012. Assessment
of host (Corylus sp.) resistance to eastern filbert blight in New
Jersey. J. Amer. Soc. Hort. Sci. 137:157-172). `Raritan` has been
shown to be highly tolerant expressing a very low average
proportion of diseased wood of only 0.7%.
For example:
Eastern filbert blight response in New Jersey: In a multi-year
trial in East Brunswick, N.J., the proportion of EFB-diseased wood
across the canopy for `Raritan` was 0.7% compared to 20.4% for
`Yamhill`, 31.2% for `Jefferson`, 48.6% for `Gasaway`, and 67.0%
for `Barcelona`.
Pollen shed: `Raritan` typically sheds pollen in East Brunswick,
N.J., 2-3 days before `Yamhill` and `Santiam` (unpatented,
Mehlenbacher et al., 2007), after `Ratoli` (unpatented, minor
cultivar from Tarragona, Spain) and prior to `Jefferson` and
`Gasaway`. `Raritan` descriptor=5.
Husk Length: `Raritan` is 1.5 times nut length, like `Barcelona`,
while `Wepster` is 2 times nut length.
`Raritan` produces kernels that are well-suited for the blanched
kernel market for use in confections and baked goods. `Raritan`
combines very high levels of tolerance to eastern filbert blight
(evaluated against Anisogramma anomala strains present in New
Jersey, US) with round nuts and kernels, high kernel percentage,
and very good kernel blanching. The tree is vigorous with an
upright branching habit that produces a desirable orchard tree when
pruned to a single stem.
Field observations in East Brunswick, N.J., and results from
greenhouse-based inoculations performed in New Brunswick, N.J.,
indicate that `Raritan` expresses a very high level of tolerance to
eastern filbert blight (EFB) caused by the fungus Anisogramma
anomala. While the cultivar is not immune to EFB, it rarely
produces stem cankers and most that develop are small in size and
lack fully formed reproductive stromata which show limited
sporulation, equating to very little to no stem dieback and a
greatly reduced canopy inoculum load even when infections are
present. The high level of tolerance (horizontal resistance) is
conferred by both of its unrelated, EFB-tolerant parent trees,
which is unlike the cultivars currently grown in Oregon and
Washington protected by the single dominant `Gasaway` resistance
allele. EFB is now present throughout the Willamette Valley of
Oregon where 99% of the U.S. hazelnut crop is grown and is endemic
to the eastern US and southern Canada, where it has been
historically impossible to grow Corylus avellana commercially.
`Raritan` was selected in central New Jersey and is adapted to the
climate present in this region. Pruning to remove cankers and
fungicide applications are currently used to manage the disease in
orchards of `Barcelona` and other susceptible cultivars in the
Pacific Northwestern US. `Raritan` is suitable for planting in
areas with high EFB disease pressure. It has shown excellent
tolerance in the eastern US where the EFB fungus is native and
genetically diverse (Muehlbauer et al., 2019).
BRIEF DESCRIPTION OF THE DRAWINGS
The figures include color photographic illustrations that
illustrate the overall appearance of the new cultivar, showing the
colors as true as it is reasonably possible to obtain in colored
reproductions of this type. Foliage colors in the photographs may
differ slightly from the color values cited in the detailed
botanical description which accurately describe the colors of the
new Corylus.
FIG. 1 is a color photographic illustration of an original unpruned
tree of the new cultivar `Raritan` hazelnut in the 15th leaf.
FIG. 2 is a color photographic illustration of nuts, husks, and
leaves of the `Raritan` hazelnut.
FIG. 3 is a color photographic illustration of nuts, cracked
shells, raw kernels, and blanched kernels of hazelnuts
`Raritan`.
FIG. 4 is a phenology chart illustration that shows time of female
receptivity, pollen shed, and vegetative budbreak of `Raritan` and
other hazelnut cultivars.
FIG. 5 is a phenology chart illustration that shows time of female
receptivity, pollen shed, and vegetative budbreak of `Raritan` and
other hazelnut cultivars.
DETAILED BOTANICAL DESCRIPTION
The cultivar `Raritan` has not been observed under all possible
environmental conditions. The phenotype may vary somewhat with
variations in environment such as temperature and light intensity,
without, however, any variance in genotype.
The aforementioned photographs and following observations and
measurements describe plants grown in East Brunswick, N.J., under
commercial practice outdoors in the field during the spring and
summer. Plants used for the photographs and description were the
original tree (15 years old) and those propagated by tie-off
layerage and growing on their own roots (six and seven years
old).
Color references herein are made to The Royal Horticultural Society
Colour Chart, 1966 Edition, except where general terms of ordinary
dictionary significance are used. International Union for the
Protection of New Varieties of Plants ("UPOV") descriptors are
described in the Mar. 28, 1979, UPOV Hazelnut guidelines. Botanical
classification: Corylus avellana cultivar. `Raritan`. Parentage:
The female, or seed, parent is Corylus avellana OSU 539.031
(unpatented, unreleased seedling), which resulted from a cross of
OSU 275.031 (unpatented) x `Sant Pere` (unpatented). OSU 275.031 is
the result of the cross `Montebello` (unpatented) x OSU 74.037
(unpatented). OSU 74.037 resulted from a cross of OSU 14.084
(unpatented) x OSU 17.068 (unpatented), which are offspring of
`Barcelona` x `Daviana` (unpatented) and `Barcelona` x `Tombul
Ghiaghli` (unpatented), respectively. `Sant Pere` is a minor
cultivar from Tarragona, Spain, known for very early nut maturity
(Tasias-Valls, 1975). `Raritan` is highly tolerant of eastern
filbert blight. OSU 539.031 is reported as similar to `Sacajawea`
(as described in Mehlenbacher et al., 2008) and `Tonda di Giffoni`
in its response to EFB in Oregon. `Raritan` has shown a much higher
level of tolerance to EFB than both `Sacajawea` and `Tonda di
Giffoni` when grown in New Jersey (Capik and Molnar, 2012). The
male, or pollen, parent is Corylus avellana OSU 616.018
(unpatented, unreleased seedling), which is the result of a cross
of `Tonda di Giffoni` x `Clark` (unpatented, Mehlenbacher et al.,
2001). It was shown to be tolerant to EFB in Oregon and selected as
a complimentary parent to the unrelated OSU 539.031 to subsequently
enhance quantitative resistance (horizontal resistance) in their
offspring. Incompatibility alleles: `Raritan` has incompatibility
alleles S3 and S22. Female parent OSU 539.031 has alleles S2 and
S22 and male parent OSU 616.018 has the alleles S2 and S3. `Tonda
di Giffoni` has the alleles 2 and 23, `Tonda Pacifica` (U.S. Plant
Pat. No. 22,715, Mehlenbacher et al., 2011b) and `Wepster` have
alleles S1 and S2, and `McDonald` has alleles S2 and S15.
Propagation (type rooted suckers): Time to initiate roots.--About
30 days at 20.degree. C. Time to produce a rooted young
plant.--About six months at 22.degree. C. Root description.--Fine
to thick; freely branching; creamy white in color. Propagation
(type whip grafting): Time to budbreak on the scions.--About 14
days at 25.degree. C. Time to produce a grafted plant.--About six
months at 25.degree. C. Plant description: General
appearance.--Natural habit is perennial shrub, but in commercial
orchards, is a single trunk tree; vigorous upright, spreading plant
habit. Growth and branching habit.--Freely branching; about 15
lateral branches develop per plant; pinching, that is, removal of
the terminal apices, enhances branching with lateral branches
potentially forming at every node. Vigor.--Vigorous, upright growth
habit. Size.--Plant height is about 6.1 meters; plant diameter or
spread is about 5.5 meters. Trunk at 30 cm above the soil
line.--8.6 cm in 2019. Texture is mostly smooth, glabrous. Trunk
color.--197C. Lateral branch description: Length.--About 40.0 cm;
ranges from 30.0 cm to 48.0 cm. Diameter.--About 5.3 mm; ranges
from 4.5 mm to 6.5 mm. Internode length (at base).--About 1.0 cm.
Internode length (at tip).--About 5.8 cm; ranges from 5.0 cm to 7.0
cm. Texture.--Smooth, pubescent. Strength.--Strong. Color,
immature.--145A. Color, mature.--146C. Color of previous seasons
branches.--199D. Foliage description: Arrangement.--Alternate,
simple. Length.--About 14.0 cm; ranges from 12.5 cm to 15.0 cm.
Width.--About 12.1 cm; ranges from 11.0 cm to 14.0 cm.
Shape.--Oblong to ovate. Apex.--Obtuse to acute. Base.--Cordate.
Margin.--Serrate. Texture, upper and lower surfaces.--Slightly
pubescent. Venation pattern.--Pinnate. Color, developing
foliage.--Upper surface 144C; lower surfaces, 145B. Color, fully
expanded foliage.--Upper surface: spring and summer, 137B; late
summer and fall, 137B. Color, fully expanded foliage, lower
surface.--Spring and summer, 138B; late summer and fall, 138B.
Venation, upper surface.--Spring and summer, 145A; late summer and
fall, 145A. Venation, lower surface.--Spring and summer, 145A; late
summer and fall, 145A. Leaf bud description: Shape.--Globular.
Length: average 8.0 mm. Diameter: average 6.0 mm. Time of leaf
budbreak.--Medium to late, Descriptor-6. `Raritan` budbreak is
approximately six days before `Jefferson`, about six days after
`Yamhill`, and two days later than `Santiam`. Color.--145B. Petiole
description: Length.--About 1.6 cm; ranges from 1.0 cm to 2.0 cm.
Diameter.--About 2.5 mm; ranges from 2.0 mm to 3.0 mm. Texture,
upper and lower surfaces.--Pubescent. Color.--144A. Flower
description: Male inflorescences.--Catkins. Color prior to
elongation.--176D. Catkin length.--Average 30.5 mm. Catkin
diameter: average 6.5 mm. Female inflorescence style color.--47B.
Female inflorescence length at full maturity: average 7.0 mm. Time
of female flowering.--Medium, Descriptor-5. Time of female
flowering compared to male flowering.--Protogyny, Descriptor-1.
Time of male flowering: Early-to-medium, Descriptor-4. Involucre
constriction.--Absent. Involucre length.--1.5 times length of nut,
Descriptor-7. Size of indentation.--Medium, Descriptor-5. Strength
of serration of indentation.--Strong, Descriptor-7. Thickness of
callus at base.--Thick, Descriptor-7. Pubescence on husk.--Absent,
Descriptor-1. Density of hairiness of involucre.--Weak,
Descriptor-3. Jointing of bracts.--On both sides, Descriptor-3. Nut
description: Length.--Average 18.6 mm. Width.--Average 19.1 mm.
Depth.--Average 15.9 mm. Nut shape.--Round. Nut shape
index.--(Width+Depth)/2*Length=0.94. Nut compression
index.--(Width/Depth)=1.21. Nut weight.--Average 2.51 grams. Kernel
weight.--Average 1.17 grams. Kernel percentage (kernel weight/nut
weight).--Average 46.6%. Number of fruits per cluster.--Two to
three. Nutshell coloration.--165B. Number of stripes on
shell.--Many, Descriptor-7. Shape of fruit apex.--Flat,
Descriptor-1. Prominence of fruit apex.--Slightly prominent,
Descriptor-3. Size of fruit pistil scar on shell.--Very small,
Descriptor-3. Hairiness of top of fruit.--Weak, Descriptor-3.
Curvature of nut basal scar.--Flat, Descriptor-2. Double
kernels.--Absent. Kernel shape.--Globular, Descriptor-2. Shape of
kernel in cross-section.--Rectangular, Descriptor-4. Lateral groove
in kernel.--Present. Corkiness of pellicle of kernel.--Lightly
corky, Descriptor-3. Disease/pest resistance.--Plants of the new
Corylus avellana exhibit a very high level of tolerance to EFB,
referred to as quantitative resistance or horizontal resistance,
caused by the fungus Anisogramma anomala (Peck) E. Muller. It has
been evaluated against the strains of the fungus present in New
Jersey. A few small cankers may develop under high disease
pressure, but they typically lack stromata equating to reduce
sporulation and subsequent orchard inoculum load. Plants have not
been challenged against all strains of Anisogramma anomala present
in North America and have not been thoroughly evaluated for their
tolerance of bud mites (Phytoptus avellanae Nal.); no bud mites
were observed on the original tree or its propagules grown in East
Brunswick, N.J. Further, no bacterial blight caused by Xanthomonas
campestris pv. corylina was observed on the cultivar during the
course of evaluations. Temperature tolerance.--`Raritan` was
selected in East Brunswick, N.J., and is targeted for production in
USDA Plant Hardiness Zone 6a to 7b. Plants of the new Corylus
avellana have been observed to tolerate temperatures from -21 to
38.degree. C.
COMPARATIVE DATA
FIG. 4 presents a phenology chart showing time of female
receptivity, pollen shed, and vegetative budbreak of `Raritan` and
other hazelnut cultivars grown in East Brunswick, N.J. over a time
period from January to April of 2018. For each of the different
indicated varieties (`Raritan`, `Jefferson`, `Yamhill`, `Santiam`,
`Ratoli` and `Gasaway`) upper and lower bar graph pairings are
provided in alignment with their respective varietal indicators,
wherein the upper (top) bar graph of each pairing represents
pistillate (female) flower development as it progresses over time
through each of four stages represented by the crosshatchings key
at the bottom of the chart; and the lower (bottom) bar graph of
each pairing represents staminate (male) flower development as it
progresses over time through each of three stages represented by
different crosshatchings defined by another key at the bottom of
the chart. The different respective stages correspond to the stages
of development as defined and described in "Flowering phenology of
eastern filbert blight-resistant accessions in New Jersey," Capik,
J. M. and T. J. Molnar, HortTechnology 24:196-208, 2014
(hereinafter sometimes "Capik and Molnar (2014)"). Stage 1 of
vegetative bud development for each of the varieties is represented
by the solid black rectangles aligned with the varietal
indicators.
FIG. 5 presents a phenology chart showing time of female
receptivity, pollen shed, and vegetative budbreak of `Raritan` and
other hazelnut cultivars grown in East Brunswick, N.J., from
December 2018 to April 2019. For each of the different indicated
varieties (`Raritan`, `Jefferson`, `Yamhill`, `Santiam`, and
`Ratoli`) upper and lower bar graph pairings are provided in
alignment with their respective varietal indicators, wherein the
upper (top) bar graph of each pairing represents pistillate
(female) flower development as it progresses over time through each
of the four Capik and Molnar (2014) stages represented by the
crosshatchings key at the bottom of the chart; and the lower
(bottom) bar graph of each pairing represents staminate (male)
flower development as it progresses over time through each of three
Capik and Molnar (2014) stages represented by crosshatchings
defined by another key at the bottom of the chart. The different
respective stages correspond to the stages of development described
in Capik and Molnar (2014). Stage 1 of vegetative bud development
for each of the varieties is represented by the solid black
rectangles aligned with the varietal indicators. Disease
resistance.--`Raritan` differs from existing Corylus avellana
cultivars based on its source and type of resistance to eastern
filbert blight (EFB) caused by Anisogramma anomala. Commercial
cultivars previously widely grown in Oregon including `Barcelona`,
`Ennis` (unpatented), `Daviana` (unpatented), `Butler`
(unpatented), etc. are highly susceptible to EFB and cannot be
grown in the eastern US without copious applications of chemical
fungicides and heavy pruning to remove infected stems. Tree death
can occur in the eastern US within 5 years of exposure to the
systemic fungus. The more recently developed cultivars `Santiam`,
`Yamhill`, `Jefferson`, `Dorris`, `Wepster`, and `McDonald` and
their associated pollenizers are protected from EFB by a single
resistance gene conferred from Corylus avellana `Gasaway`. This
gene provides a high level of resistance in Oregon and Washington
where the diversity of the fungus is limited (Muehlbauer et al.,
2019), but does not provide a similar level of protection from
disease in the eastern US where the pathogen is endemic and
genetically diverse (Capik and Molnar, 2012; Muehlbauer et al.,
2018). `Raritan` hazelnut is highly tolerant to EFB but does not
carry the single `Gasaway` resistance allele. It was developed by
crossing two unrelated Corylus avellana plants both exhibiting a
high level of tolerance and then selecting offspring exhibiting
enhanced levels of tolerance in the presence of high disease
pressure in East Brunswick, N.J. While `Raritan` plants are not
immune to EFB, they have been shown to rarely get destructive stem
cankers that lead to stem die-back and subsequent yield decline. In
a multi-year trial in East Brunswick, N.J., completed in winter
2018 and spanning more than 8 years of exposure to EFB, the average
proportion of diseased wood (total length of EFB-diseased stems per
tree divided by total length of shoot growth) for `Raritan` was
0.7% compared to 20.4% for `Yamhill` (unpatented, Mehlenbacher et
al., 2009), 31.2% for `Jefferson` (Mehlenbacher et al., 2011a), and
48.6% for `Gasaway`. Previous studies in New Jersey showed the
proportion of diseased wood of `Barcelona` to be 67.0%, `Tonda di
Giffoni` 39%, and `Sacajawea` 21% (Capik and Molnar, 2012).
Differences were also observed in the number of cankers and average
canker length for `Raritan` in comparison to `Yamhill`,
`Jefferson`, and `Gasaway` in the study completed in 2018.
`Raritan` exhibited an average of 7.0 cankers per tree with an
average canker length of 20.3 cm. In contrast, `Gasaway` exhibited
an average of 93.0 cankers per tree with an average length of 130.8
cm, `Jefferson` exhibited an average of 36.9 cankers per tree with
an average length of 72.3 cm, and `Yamhill` exhibited an average of
40.5 cankers per tree with an average length of 37.9 cm. As
reported in Capik and Molnar (2012), and as a further point of
comparison in regard to EFB response, `Barcelona` exhibited an
average of 20.4 cankers per tree with an average length of 61.9 cm,
`Tonda di Giffoni` exhibited an average of 39.0 cankers per tree
with an average length of 24.5 cm, and `Sacajawea` exhibited an
average of 7.7 cankers per tree with an average length of 21.5 cm
(Capik and Molnar, 2012). While `Sacajawea`, a cultivar known to
exhibit tolerance to EFB, exhibits similar canker numbers per tree
and canker length to `Raritan`, its proportion of diseased wood is
much higher at 21% compared to 0.7%. Nut and kernel
characteristics.--`Raritan` hazelnut is targeted for the blanched
kernel market and specifically for nut production in the eastern
United States in USDA Plant Hardiness Zones 6a to 7b where most
existing cultivars of Corylus avellana cannot be grown due to the
impacts of EFB. The nut shape is round although slightly compressed
along its depth. Kernels are round with a slight point. The average
single nut weight over the past 6 years for `Raritan` is 2.51 g and
average single kernel weight is 1.17 g, with an average kernel to
nut ratio of 46.6% (FIG. 3). `Raritan` nuts and kernels are smaller
than those of `Barcelona`, `Jefferson`, and `Sacajawea`, and also
differ in kernel to nut ratio. For example, `Barcelona` (as
described in Mehlenbacher et al., 2008) had an average single nut
weight of 3.85 grams, average single kernel weight of 1.66 grams,
and an average kernel to nut ratio of 43.1%. `Sacajawea` (as
described in Mehlenbacher et al., 2008) had an average single nut
weight of 2.79 grams, an average single kernel weight of 1.45
grams, and an average kernel to nut ratio of 52.1%. `Jefferson` (as
described in Mehlenbacher et al., 2011a) had an average single nut
weight of 3.69 grams, an average single kernel weight of 1.66
grams, and an average kernel to nut ratio of 42.9%. `Raritan` nuts
and kernels are relatively similar in size to `Yamhill`, `Wepster`,
and `McDonald` but differ in several aspects including ratio of
kernel to nut and pellicle removal after roasting. For example,
`Yamhill` (as described in Mehlenbacher et al., 2009), had an
average single nut weight of 2.34 grams, an average single kernel
weight of 1.13 grams, and an average kernel to nut ratio of 49.3%.
`Wepster` (as described in Mehlenbacher et al., 2014) had an
average single nut weight of 2.39 grams, an average single kernel
weight of 1.11 grams, and an average kernel to nut ratio of 46.6%.
`McDonald` (as described in Mehlenbacher et al., 2016) had an
average single nut weight of 2.39 grams, an average single kernel
weight of 1.21 grams, with an average kernel to nut ratio of 50.7%.
Raw kernels of `Raritan` have a light brown pellicle with a
moderate amount of attached fiber (average rating was 2.0 on a
scale of 1 [no fiber] to 4 [much fiber] with average based on 6
years of evaluations). Pellicle removal after roasting at
150.degree. C. for 15 min and rubbing is rated on a scale of 1
(complete pellicle removal) to 7 (no pellicle removal). Most of the
pellicle on `Raritan` kernels is removed after roasting with an
average rating of 2.2 (averaged from 6 years of evaluations).
`Raritan` demonstrated better average pellicle removal than that
reported in Oregon for `Barcelona` (4.2 out of 7.0 as described in
Mehlenbacher et al., 2008), `Jefferson` (3.9 out of 7.0 as
described in Mehlenbacher et al., 2011a), `Yamhill` (4.1 out of 7.0
as described in Mehlenbacher et al., 2011a), and `McDonald` (3.8
out of 7.0 as described in Mehlenbacher et al., 2016). `Raritan`
has similar pellicle removal to `Sacajawea` (2.9 out of 7.0 as
described in Mehlenbacher et al., 2011) and `Dorris` (2.4 out of
7.0 as described in Mehlenbacher et al., 2013), whereas, `Tonda
Pacific` as described in Mehlenbacher et al. (2011), had superior
pellicle removal with a score of 1.5 out of 7.0. The average
percentage of good kernels (kernels free of defects) were
calculated for `Raritan` over three years of evaluation and found
to be 88.4%. There was a very low incidence of moldy kernels
(average 0.8%), blank nuts (0.4%), and shriveled kernels (1.2%).
The majority of the defects were attributed to sucking insect
feeding damage, primarily Brown Marmorated Stink Bug (Halyomorpha
halys, Stal, 1855), which equated to an average of 9.2% kernels
displaying feeding scars and their associated reduction in quality.
Note that no chemical control measures were utilized and Brown
Marmorated Stink Bug pressure is high in New Jersey. The percentage
of good kernels for `Raritan` was considerably higher than that
reported for `Barcelona` in multiple reports from Oregon (60.9%
good kernels reported in Mehlenbacher et al. [2008] and 69.4% in
Mehlenbacher et al. [2013]). The average percentage of good kernels
for `Raritan` grown in New Jersey is relatively similar to the
range reported from Oregon for `Yamhill`, `Jefferson`, `Dorris`,
and `McDonald`; however, the percentage of moldy nuts was generally
lower. There were no instances of doubles, black tips, or poorly
filled kernels for `Raritan`. Nut maturity date.--The nuts of
`Raritan` are typically borne in clusters of 2-3 and sometime 4 in
husks about 50% longer than the nuts. The husks are flared and slit
down the side (FIG. 2), and open as they dry at maturity. About 90%
of the nuts fall free of the husk at maturity (range 80-100%). The
other 10% of the nuts come out of the husks as they move through
the harvester. When mature, the shells are tan to light brown in
color. Harvest date on average is around 7 days before `Jefferson`
when grown in East Brunswick, N.J., typically around first week of
September. Incompatibility and pollinizers.--The trees set a
moderate to high amount of catkins that shed pollen in early
mid-season a few days prior to `Yamhill`. Pollen has been collected
and used in several controlled pollinations, and both quantity and
viability appear to be good. `Raritan` has incompatibility alleles
S3 and S22 as determined by fluorescence microscopy. Both alleles
are expressed in the female flowers, but only S3 is expressed in
the pollen because of dominance. By convention, alleles expressed
in the pollen are underlined. Time of pollen shed and female
receptivity were recorded weekly from early December 2017 to late
March 2019 (FIGS. 4-5). Climatic conditions vary each year and
impact dates of bloom but not usually the order of progression of
bloom among cultivars. Female inflorescences of `Raritan` emerged
in early mid-season and were fully receptive in mid-February (New
Jersey). Pollinizer cultivars that shed compatible pollen in
midseason and late midseason are recommended, with hybrid hazelnut
seedlings (Corylus americana x C. avellana) planted as pollenizers
in eastern and northern regions where cold temperatures and
fluctuating climatic conditions can affect pollen production of C.
avellana. Alternative orchard designs include planting different
eastern filbert blight resistant cross-compatible cultivars in
adjacent rows to augment pollen production. Flowering times will
continue to be observed and pollinizer recommendations adjusted
accordingly. Pollinizers must be selected that express a high level
of EFB resistance to eliminate/reduce the need for fungicide
control in the entire orchard. Pests and diseases.--Based on field
trials under high disease pressure and greenhouse inoculation
trials, both performed in New Jersey, `Raritan` expresses a very
high level of tolerance to EFB (quantitative resistance). Fungicide
applications to control EFB are not expected to be needed. Small
cankers that may develop can be removed through pruning to reduce
inoculum load in production orchards. Susceptibility to bacterial
blight caused by Xanthomonas campestris pv. corylina has not been
quantified, but the original seedling tree and clonal trees in the
replicated trials were not affected. Susceptibility to big bud mite
(primarily Phytoptus avellanae Nal.) has not been quantified, but
the original tree and trees in the replicated trials were not
affected. Propagation.--Layers of `Raritan` are vigorous and root
well similar to standard cultivars of Corylus avellana
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