Getting started with CHESTNUTSErin Lizotte, Michigan State Universitytaylo548@msu.edu

Overview

• Castanea • Market• Production• Postharvest• Resources

CastaneaThere are three species of chestnut that contribute to the genetic makeup of chestnut trees planted in orchards;

Chinese, Castanea mollissimaJapanese, C. crenataEuropean, C. sativa

Some of today’s cultivars are hybrids or crosses among these three species. The most prevalent commercial cultivars are known as ‘french-style’ and are Japanese X European crosses originally developed in France.

Castanea

• Native to moist, temperate regions of the northern hemisphere

• Evidence of its cultivation by man dates back to around 2000 BC

• Eastern Asia and southern Europe relied heavily on chestnut for sustenance

• Until the introduction of the potato, communities which had scarce access to wheat flour relied on chestnuts as their main source of carbohydrates

Castanea

• Chestnut kernels are starchy

• When dried, chestnuts resemble grain

• Known as the bread tree in many parts of the world

www.builtlean.com, National Nutrient Database

Global market• China is the largest producer of chestnut in the

world (70%), and produced just shy of 4 billion pounds of chestnuts in 2011!

• U.S. chestnut production is less than 1% of total world production

• Approximately 1,200 farms growing chestnuts on just over 3,300 acres in the U.S.

• The U.S. imported 3,781 metric tons of chestnuts valued at over $12.4 million in 2011

Michigan Industry• Michigan is largest domestic producer• Production is concentrated in the “fruit belt” and

southern Michigan• ~600-700 acres in Michigan growing shy of 1M pounds• Novel crops offer growers the chance to capitalize on

new and underserved markets, innovate, and diversify • Establishing a new industry and market is also an

enormous challenge• Nationally, chestnut acreage in the U.S. has increased

substantially over the past 30 years with the largest acreages in MI

Cost of production• Completed in 2014• The estimated cost of producing grafted, French-

style chestnuts is $0.81USD/pound (~$1CAD)• Based on a full production yield of 3,500 pound/acre

(392kg/hectare) and a minimum planting size of 10 acres (~4 hectares)

• Calculation is based on estimates of operating costs, harvest costs, management, interest and tax costs

• Includes an amortized cost of establishing an orchard and employing the land in production

Cost of production

• Chestnut price required to justify investing in a block of chestnuts to ensure getting a target rate of return on equity capital, covering the annual cost of using land, the opportunity cost of family labor and management, and other allocated costs

• These are the break-even yields across different rates of return, price levels and yield requirements.

Site requirements• Well drained,

relatively fertile soil (sandy loam with some organic matter)

• pH range of 5.5 to 6.5• Planting on hills is

better than on flat land• good water drainage• drainage of frost

Site requirements• Chestnut are arguably

more cold tolerant than early blooming hort crops

• Bloom in June• Still can be damaged

by fluctuating winter temperatures

• Individual sites vary, a lake Michigan view isn’t a ringer

Production• The species that make up chestnut orchards in

various regions of the United States are chosen primarily due to grower response to chestnut blight

• Western states are free of blight and plant blight–plant susceptible European/Japanese chestnuts

• Most eastern growers plant the naturally blight-resistant Chinese chestnut due to the continued presence of the blight pathogen

• Michigan is the only state where growers plant both Chinese and European chestnut species in orchards

Production

• The European hybrids are superior to Chinese:• Produce 4 to 5 times

more nuts• Reach production

sooner• Consistent in habit

• Growers must always monitor for chestnut blight

Seedlings or grafted trees?

Seedlings• Often Chinese• Trees grown

from a nut• Genetically

different• Variable bloom

and harvest• Variation in

yields

Grafted trees• Almost exclusively

hybrids • Selected for

superior characteristics

• Genetically identical

• Reliable characteristics

• Bear earlier

Scion

Rootstock

Cultivars• Colossal and Bouche de

Betizac and currently the two most productive and promising cultivars

• Chestnuts are pollen sterile so at minimum two pollinizers are required

• Pollinizers (also bearing)• Precoce Migoule• Labor Day

CultivarsColossal (European/Japanese)• From the foothills of the High Sierra in California,

bred more than a hundred years ago• Characteristics include excellent production,

large nuts, and sweet taste after it has cured• Trees go into production within three years after

planting, sometimes production occurs in the second year

• Suggested pollinizers include Precoce Migoule and Labor Day

• Susceptible to blight

CultivarsBouche de Betizac (European/Japanese)• This cultivar produces large crops of big nuts that

taste good and are easy to peel, well adapted for growth in Michigan

• Resistant to the Asian gall wasp, an invasive recently documented in Michigan

• The nut ripens in mid-October, just after Colossal• Suggested pollinizers include Precoce Migoule

and Labor Day• Susceptible to blight

CultivarsPrecoce Migoule (European/Japanese)• Well adapted to the Michigan

climate, copious, early pollen that is synchronized with Colossal and Precoce Migoule

• Nuts mature at least two weeks earlier than Colossal making it a candidate for colder regions

• Suggested pollinizer Labor Day

• Susceptible to blight

CultivarsLabor Day (Korean, Japanese, Chinese chestnut hybrid?)• Prolific pollen producer, sheds

pollen early and for three weeks• It is also a good nut producer, but

not as prolific as the Colossal, Bouche de Betizac, or Precoce Migoule

• Will produce nuts much earlier than Colossal

• Suggested pollinizer Precoce Migoule

• Resistant to blight

Internal Kernel Breakdown

Do not place Chinese chestnuts with European hybrids as it causes a pollen incompatibility

IKB Healthy

Orchard planning

Spacing and pollinizer placement are critical

Win

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ion

Planting• Planting takes place in the fall• Tree holes should be large enough to

accommodate the root system • Make sure the hole isn’t glazed• Keep bare roots moist• Do NOT put chemical fertilizers in the hole• The graft should be located well above the soil line• Be ready to provide pest control, irrigation and

weed control immediately• Apply mouse guards and paint trunks before winter

Nutrient management • Many MI soils provide nutrients in

sufficient levels for chestnut • Perform a soil test before planting• A soil test provides you with soil pH,

texture and nutrient status • Even though optimum nutrient levels

for P, K, Ca, and Mg are not known for chestnuts, a soil test can provide you with information to base your nutrient and sulfur or lime addition decisions

Nutrient management Nitrogen, 0-5 years

Nutrient Management, Nitrogen 5+ yearsRates are determined by tree size and vigor. The diameter of the trunk is multiplied by the nitrogen rate based on last years growth• Low vigor: If tree growth is low (<8 inches per year) then a

multiplier rate of 1/6 lb. (2.7oz.) N per inch of trunk diameter is used.

• Normal vigor: If tree growth is normal (8-12 inches per year) then a multiplier rate of 1/8 lb. (2oz.) N per inch of trunk diameter is used.

• Excessive vigor: If growth is vigorous (>12 inches on average) then a multiplier rate of 1/10 lb. (1.6oz.) N per inch of trunk diameter

• Note: No more than 1 lb. of actual nitrogen should be applied per tree annually

Example N calculation for bearing tree• 5 inch trunk diameter, 5 inch terminal branch length last

year, Ammonium sulfate (21-0-0). • Your average terminal growth last year was 5 inches,

indicating a low vigor, you would need 2.7oz. N per inch of trunk diameter

• 5” trunk×2.7oz. N=13.5 oz. actual N needed per tree • Ammonium sulfate is only 21% nitrogen, so to determine the

rate of product needed, use the following formula:• Actual nitrogen (oz.) ÷ by nitrogen in product (%) = product

needed (oz.)• 13.5 oz. actual N / 0.21 % N in ammonium sulfate = 64.3 oz.

of ammonium sulfate per tree

Nutrient management• Snowmelt applications generally do not

influence the nitrogen status or strength of current season flower buds or fruit set.

• Applications during the summer, particularly after current season shoot growth has been completed, are more likely to result in improved nitrogen status of the buds for the next season.

• Avoid late summer or fall applications, they may limit tree hardiness and proper shut down.

Integrated pest management

• Primary pests in Michigan• Blight• Potato leafhopper• Mites (European red and two-spotted spider mites)• Rose chafer and Japanese Beetle

• Potential pests• Chestnut weevil (lesser and larger)• Asian chestnut gall wasp

Pest management

• Primary pests• Chestnut blight• Potato leafhopper• Mites• Beetles

Chestnut blight• Caused by a fungi called Cryphonectria

parasitica• Introduced into the United States in the

early 1900s and has spread throughout the range of the American chestnut

• The disease causes a canker disease on stems and branches

• On the highly susceptible American chestnut, cankers quickly girdle the stem and as a result the aerial portions of the tree die back

• Cannot infect the roots, which retain the ability to produce stump sprouts

Blight susceptibility • Chinese can be infected but is mostly tolerant, can

be a carrier • European chestnut is susceptible• Japanese chestnut is tolerant, but again, it can carry

the fungus• Keep blight away by keeping American chestnut

trees off the farm• Don’t bring in stock from areas where blight is found

Blight management • Destroy infected trees in an effort

to eradicate the disease• Growers suffer significant

costs• Hypovirulence is the future

• Virus of the fungi that decreases virulence and allows recovery (as in Europe)

• Currently identified hypovirulent strains in Michigan

Potato leafhopper• Adult leafhopper is pale to bright green and about 1/8

inch long• Adults are very active, jumping, flying or running when

disturbed• The immature forms, or nymphs, are pale green and

wingless• Nymphs run forward, backward or sideways when

disturbed• Does not overwinter north of the Gulf states, adults

migrate north each spring on southerly winds and are deposited during May and June in spring rains

Potato leafhopper

Nymph

Adult

Damage• PLH feed near the edges of

the leaves with piercing-sucking mouthparts

• Heavily damaged leaves have necrotic and chlorotic edges and abscise from the tree

• Severely infested shoots produce small, bunched leaves

Scouting for PLH• Scouting should be performed weekly to ensure

detection early and prevent injury• More frequent spot checks should be done

immediately following rain storms• For every acre of orchard, select 5 trees to

inspect and inspect the leaves on 3 shoots per tree (a total of 15 per acre)

• Flip the shoot over and look for adults and nymphs on the underside of leaves

PLH management• The most common classes of insecticides

recommended for control include the pyrethroids, carbamates, neonicotinoids and organophosphates

• Carbamates and organophosphates are broad spectrum and can disrupt natural enemies so only use when necessary (like targeting another pest at the same time)

• Pyrethroids can cause mite flaring but are less expensive

• Neonicotinoids are longer lasting and narrow spectrum making them a solid choice for management

Mites

• European red mite and likely two-spotted spider mites are pests for many growers

• Both species can be found in the orchard season long and can do considerable damage to the trees, particularly when in high numbers or on young trees

• No established threshold, but 100% control is likely not necessary

TSSM

ERM

Symptoms of mite damage• Injury is cumulative• Leaves appear mottled,

stippled, and in more severe cases bronzed

• Injured leaves have reduced photosynthetic activity potentially leading to reduced nut size, and return crop load potential as well as increased sensitivity to winter injury

Japanese beetle• Adult Japanese beetles are 3/8-

inch long, metallic green beetles with copper-brown wing covers

• Adults emerge from the ground and begin feeding on plants in June

• Individual beetles live about 30-45d• Activity is concentrated over a four

to six week period, after which the beetles gradually die

• Large, well established trees can likely tolerate considerable feeding damage

Japanese beetle damage• JB skeletonize

leaves and feed in large groups

• Can be particularly destructive to young trees with limited leaf area

Scouting for JB• Take a walk—they

aggregate so they are highly visible!

• Check preferred hosts in the vicinity (apples are a favorite)

• Wild raspberry, blackberry, Virginia creeper, wild grape or sassafras are highly attractive and beetles will aggregate on these plants

Rose chafer• Feed on many crops grown

on sandy soils• There is a single generation

per year with the adults showing up in June

• The activity of adults typically lasts for only two to three weeks

• Particularly damaging on young trees with limited leaf area

Scouting for RC• They are often found

in mating pairs and fly during daylight hours

• Visual observation via transect is the best method for locating them

Available insecticides and efficacy

www.chestnuts.msu.edu

Harvest considerations

• Nuts do not all mature and drop at once• Orchard size should be factored in• Labor availability • Nuts should be moved into cold storage

within two days for peak quality and to minimize depredation—this means you need to be able to cover your entire orchard every two days.

Harvester options

• Hand harvest some pick-up tools/assists available such as Nut Wizard

Lehmans.com

Harvester options

• Sweep (everything) in orchard with off-line secondary cleaning.

www.mequipment.com

Harvester options• Vacuum based

systems• Vacuum and

sweeper combos are also available

www.ruralworld.com.au

Storage

• If you are planning to direct market, there are some additional considerations• Sorting• Cleaning• Cold Storage• Packaging• Shipping

Marketing• Some growers do direct sales• Chestnut Growers, Inc. handles almost all of the

commercially produced chestnuts in Michigan• CGI products include peeled-frozen chestnuts,

dehydrated sliced chestnuts, chestnut flour, and fresh chestnuts

• Boasts the only commercial chestnut peeler in North America

• Sells the crop every year and are actively recruiting and assisting new growers

Thanks!

• Check out chestnuts.msu.edu• Cost of production

• Subscribe the MSUE News Fruit and Nut Report!• Chestnut events, resources and announcements

• Join a grower group!