Progress report for FNC24-1437
Project Information
I am a nurseryman running Dispersion Farms which provides locally adapted, superior selections of a staple crops with a focus on hybrid hickory crosses between Bitternut hickory and Shagbark hickory. I also work on the project of developing a fully adapted zone 4 American persimmon for pulping and a high pod sugar content, zone 4 capable honey locust for silvopasture. I have a 1/8th acre nursery where I grow seedlings and clones for sale, I manage more extensive plantings for the breeding of my focus crops, and I subsistance farm.
I grew up picking up hickories with my parents but have been working with hickory professionally now for 3 years and have been taught and collaborate with:
Sam Thayer - the first person to press bitternut hickory for oil with modern machinery and who I will be test-pressing variety selections with.
Jesse Marksohn - the largest scale nursery-person focusing on hickories for oil pressing and a partner in evaluations of trees in the Northeast.
Buzz Ferver - a nursery-person who taught me to graft.
Zach Elfers - a nursery-person and collaborator in evaluations of trees in the Mid-Atlantic region.
In my work with hickory, I travel to midwestern plantings of hybrid hickories, assess individuals for breeding and commercial characteristics, and tend to the trees with potential. The four plantings that I will be evaluating as part of this grant and have been working with already are:
1) Weschcke Population in River Falls, WI which has ~80 grafted trees grafted around 1960 and hundreds of hickory offspring.
2) Badgersett Population in Canton, MN which has ~300 seedling hickories planted ~1980 originating from the Weschcke population.
These plantings were selected due to the presence of bitternut hickory and their hybrids within the population
This is a research project with two main barriers, both of which
will be important to break in order to make hickories a crop in
the upper midwest.
- Tree evaluations need to be done on hundreds of hybrid
individuals in the upper midwest to provide variety
recommendations for growers in the upper Midwest. Currently, only
a small handful of subpar hickory selections have been made and
often have been trialed only outside of zone 4/5 upper midwest.
Additionally, evaluations are almost entirely anecdotal and
insufficient to give growers security in planting varieties that
are of high cost and may take over a decade to bear nuts. - A procedure for epicotyl grafting hickories (grafting onto a
sprouted nut) in zone 4/5 needs to be developed. Traditional
nursery growing of hickories is challenging and problematic due
to the high costs of producing grafted trees because of slow
seedling shoot growth, strong taproot dominance, and the stress
responses of hickories.
The first objective is to select 10 hybrid hickory varieties to
be recommended to growers in zone 4/5 upper midwest that will
provide maximum profitability and flexibility to the grower and
release them for sale. I will select hickory trees that are easy
to propagate, fast growing, disease resistant, heavy bearing,
easy to harvest and husk, and bears multipurpose nuts. A
multipurpose nut that grows in zone 4/5 upper midwest can only be
found in some bitternut shagbark hybrids. A multipurpose nut is
one that can be used for multiple of the following purposes:
home-scale cracking, machine cracking, oil pressing, and milking.
The characteristics that allow for a combination of these four
puroses are:
- the kernel weight should be as large as possible with 2.0g as
a minimum - the nut should have a thin enough shell that it can be
pressed in-shell for oil reliably. Current knowledge estimates
that the nut should be at or exceed 47% kernel. - the nut should crack out exceedingly well in a home scale
hand cracker with at least 50% of kernel to halves and 90% easy
extraction to large pieces - the nut should be milkable which requires that the kernel,
pellicle, and shell not to contain tannins. - The nut shape should lend itself to automated machine
crackering.
The second objective of this project is to determine the details
in the procedure of epicotyl grafting hickories to get maximal
grafting success. Though I have successfully epicotyl grafted
with Black Walnut and the method has been successful with pecan,
epicotyl grafting has not been applied to bitternuts, shagbarks,
or their hybrids. Many specifics of the epicotyl grafting process
with hickories needs to be discovered including: the best hybrid
rootstock, the best shoot development stage for high graft
success and rapid growth, the best waxing and compression method,
and the lowest input nursery growing conditions that work with
the Wisconsin climate.
For the epicotyl grafting trials, three rootstocks will be
tested: "Fairbanks", "Weschcke", and a 3.0g kernel shagbark. Past
trials show that pure shagbark and "Weschcke" produce the
thickest diameter epicotyl which is easier to handle. 100%
beeswax will be used that has no oil in the mix because the oil
seems to have killed callus in past trials. Suxgumoe Plants Graft Clips will be used as
determined by my past trials and sizing. Three compression
and wrapping methods will be used: parafilm wrapping, parafilm
wrapping and clipping, and only clipping. All grafts will be
waxed to the bottom of the graft union. Nuts will be placed in a
germ chamber for 20 to 25 days at 90F and epicotyls of length
varying from 1 inch to 6 inches will be grafted, segregated, and
labeled with all characteristics of relevance to this study.
Grafts will be callused in a greenhouse heated to 70F, fans will
run above 85F, and sides will be rolled up to help keep temps
within this range. After 5 weeks, 75% of grafts will be planted
into a rodent proof nursery bed for two years and 25% will be
planted into 9" tall 4" wide tree pots. Winter survival rates
will be noted for field planted grafts. Nut germination will be
initiated on ~March 25th, grafting will occur on ~April 20th, and
transplanting will occur on ~May 25th. A minimum of 300 grafts
will be made.
Research
Collect samples from every tree for dry down and later evaluation. Label everything. Take data on everything even if it doesn't seem relevant because it may teach you about something interesting later. I discovered hickory catkin abnormalities and differences in peduncles in hybrids because I was watching for things i did not yet know about.
I collected a ton of data as a result. The evaluations will be much more rounded and complete after next years harvest season. Due to lack of uniformity of tree growth fertility and spacing all filed evaluations are based off of context using my personal judgement. I believe these visual evaluations are critical for understanding crowded trees; this is atypical in academia but essential in my context.
Educational & Outreach Activities
Participation Summary:
I presented at the Northern Nut Growers Association conference in Syracuse, NY in August 2024 about notes and progress on epicotyl grafting hickories and some notes on new variety selections. I had many follow up conversations afterward with individuals to share more about epicotyl grafting and the varieties. There were about 300 growers and 100 ag professionals present for the presentation. This talk reviewed top learnings from this years epicotyl grafting. The notes shared are as follows:
- 78F-85F greenhouse setting
- 50% cheeswax, 50% beeswax NO oil mixed in! Oil kills cambium! Wax whole epicotyl
- Melon and tomato grafting clips (red and clear)
- Shagbark rootstock or dominant shag rootstock genetics
- Cleft grafting close to the nut
- Burying the whole graft union and clip so no epicotyl is above soil level
- Use thick scion
- Aligning one side only
- One large bud on the scion stick
- 3”+ epicotyl length before grafting
- 50% take rate was achieved with these rules
I have made 2 posts on hickory variety evaluations and seedling population data to the North American Hickory and Hican Nut Growers group on facebook which has 1.6k members. The posts are as follows:
November 8th 2024:
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Average DBH is 6” though many are suppressed and not yet bearing.
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Average DBH is 7” for trees that bore enough nuts to evaluate this year. Bearing has been low the past two years due to low fertility, adverse weather, and the mast year in 2022.
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There were 11/329 trees of good or greater bearing in 2023.
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There were 48/329 trees of good or greater bearing this year.
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There were 9/329 trees that produced at least a moderate crop last year and at least a good crop this year.
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3/329 trees produced a good or greater crop in 2023 and 2024; one had a low year in 2022 and the other two were not observed in 2022.
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40/329 of the trees have moderate or high susceptibility to anthracnose (12%)
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4/329 of the trees are susceptible to phomopsis gall (1%)
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75/329 trees have moderate or greater susceptibility to phylloxera (23%).
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20/329 trees are moderately or greater preferred by the yellow bellied sapsucker (6%).
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55 trees are confirmed pollen sterile of the 198 trees that produced catkins this year; more are possibly pollen sterile and need more observation to confirm (28%).
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65/181 are over 40% kernel this year
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17/181 are over 45% kernel
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124/181 were over 2.0g kernels
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67/181 over 2.5g kernels
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40/181 at or above 3.0g
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16/181 at or above 3.5g kernels.
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The average kernel weight of the 17 over 45% kernel was 3.1g.
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There are 10 trees at or over 48% kernel.
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12 of the trees over 45% kernel trees have already been confirmed as pollen sterile while 4 need more observation to confirm and these are possibly not pollen sterile and one tree at 46% is confirmed pollen fertile.
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There are many interesting pollen fertile trees that have worthy records within the 40-45% kernel range.
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31 are excellent or very interesting trees but I do not yet have enough data to say they are ready for production as clones. There are many that have all the traits we want in a multipurpose nut other than weevil resistance and proven yield. Whether it is this generation or the next, we will get there. A few of note are “Shiver” “Cheeks” and “Fairand”
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2 trees have a good enough known production record and a good enough nut to be ready for production for oil or kernel in my opinion (more are ready for milking but that is a last resort). Those two trees are “Butter Berry” and “Snack Shack”
Learning Outcomes
There is a lot to still learn but one more year of evaluations have been done and some successful epicotyl grafts have made it through one growing season. The main lessons are shared in the outreach section of this report but I will replicate the epicotyl grafting lessons here because they are very important learnings:
- 78F-85F greenhouse setting
- 50% cheeswax, 50% beeswax NO oil mixed in! Oil kills cambium! Wax whole epicotyl
- Melon and tomato grafting clips (red and clear)
- Shagbark rootstock or dominant shag rootstock genetics for thicker epicotyl
- Cleft grafting close to the nut
- Burying the whole graft union and clip so no epicotyl is above soil level
- Use thick (not skinny matching width) scion
- Aligning one side only
As for general lessons learned from evaluations:
- fertility affects nut production heavily so evaluations must be made while knowing fertility levels
- some trees drastically change kernel percentage from year to year. Others are quite consistent
- some trees do have a natural affinity towards heavy bearing but without fertility, it appears this comes with weevil vulnerability
- yield evals should be done over a 3 year minimum period and severe weather can affect yield consistency drastically; weschcke is a known annual heavy bearer and it has not born the past two years in River Falls, WI
- One large bud on the scion stick
- 3”+ epicotyl length before grafting
- 50% take rate was achieved with these rules
- There are 40 or so trees that are highly interesting between the weschcke and badgersett population that deserve intense further study.
Project Outcomes
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