A Pest and Disease Primer for Unity Farm, Sherborn, MA

Introduction

Unity Farm is a 15 acre Massachusetts 61A designated farm property, which practices organic

pest and disease control, but is not certified organic. The property includes oak/black birch /

maple dry woodland; a seasonal wetland/vernal pond surrounded by ferns; an orchard with 55

types of apples, 180 high bush blueberries, numerous stone fruits, raspberries, elderberries,

strawberries and asparagus beds; a 50x21 hoop house with 16 raised beds; 10,000 pounds of

oak logs growing shiitake mushrooms; and permaculture in the woodlands including paw paw

and American ginseng. 150 animals, including alpaca/llama, chickens, ducks, geese, guinea

fowl, and great pyrenees mountain dogs live in 3 pastures. 14 hives including carneolian, rus-

sian, and italian bees provide pollination. The farm is also a bonded farmer winery/cidery.

The primary income of the farm is from the sale of alpaca fiber, honey/mead, hard cider, fruits,

and shiitake mushrooms. Sales of vegetable produce is limited due to small production and

uneven results due to pests and disease

The purpose of this paper is to document the vegetables grown on the farm, the diseases/pests

experienced, and the treatment/risk mitigation available to reduce loss using organic methods.

In addition to the academic literature, source material for this evaluation includes interviews with

local farmers in Sherborn, MA at Sweet Meadow Farm, Dowse Orchards, and Sunshine Farm.

This paper is organized by vegetable species.

Legumes

The residents of Unity Farm are vegans and vegetarians, deriving much of their nutrition from

legumes. Additionally ,legumes are used extensively in crop rotation and cover crop pro-

grams, proving nitrogen fixation.

Bush beans including Jacob’s Cattle and Cranberry Beans are grown in the hoop house in two

seasons - Spring to Summer and Summer to Fall. The pods are harvested once the plant has

died and the bean seeds have dried.

Scarlet runner beans are grown annually and harvested when pods are mature. Some early

beans are harvested when young and are eaten as a vegetable.

Snow peas and snap peas are grown in the early spring in the hoop house. Pods are har-

vested before they become tough and fibrous

P ests

During the 3 years in which we have grown pea and bean species, we have had few pests at-

tacking the legumes.

A review of the literature (Myers) suggests that pea pests include loopers, cutworms, army-

worms, grasshoppers, pea aphids, pea leaf weevil, pea moth, pea weevil, and wireworms. Bean

pests include lygus bugs, nitidulids beetles, aphids, armyworms and cutworms, grasshoppers,

pea leaf weevil, seed corn maggot, gray garden slug, spider mites, cucumber beetles, beet leaf-

hopper, and wireworms. Although cucumber beetles have been a problem in the hoop house,

they have not been an issue with bean species. Barrier methods appear to be effective in con-

trolling these pests - applying row covers to prevent beetles from feeding and removing dam-

aged portions of plants.

Diseases

We have not experienced diseases in any legume to date. The literature (Myers) suggests

that pea diseases include seed rot, damping-off, fusarium wilt, basal stem rot, powdery mildew,

downy mildew, root rot, and bean leaf roll. Bean diseases include seed rot, damping-off,

seedling blight, root rot, sclerotinia, curly top, bean common mosaic, and bean yellow mosaic.

Crop rotation and using resistant varieties is effective in controlling these diseases. If infection

does occur then affected plants should be destroyed.

The experience of local farmers mirrors ours - legume pest and disease problems are infre-

quently encountered in our region. Harvesting and processing bush beans is labor intensive

and although we devote significant portions of our hoop hose to bean production, local farmers

do not typically raise significant quantities of bush beans for resale. This may explain the low

quantities of bean pests in our area. “U-pick peas” are available from local farms, but acreage

planted is small.

Brassicas (Cabbage, Broccoli, Cauliflower)

Unity Farm has been entirely unsuccessful growing Brassicas. Pests, especially the larva of

the cabbage butterfly have destroyed all brassica plants before harvest. We have planted cab-

bages, broccoli, and cauliflower. One of the co-owners (Kathy) is Korean, so we had hoped to

produce local kimchi using our cabbage, garlic and peppers. Clearly, an intervention is

needed to improve our cabbage production.

Pests

Typical pests per the literature (Fritz) include cabbage looper, imported cabbageworm, dia-

mondback moth, cutworms, zebra caterpillar, thrips, cabbage aphid, green peach aphid, turnip

aphid, cabbage maggot and flea beetle.

Although we have experienced flea beetle problems on eggplant in the hoop house, we have

not had flea beetle issues with brassicas. The imported cabbageworm is our issue and it has

devastated our plantings. Although established plants can tolerate 50-percent defoliation until

the pre-heading stage without yield loss, our infestation has reduced yields to nearly zero. Con-

trols include azinphosmethyl (Guthion), Bacillus thuringiensis (BT), carbaryl (Sevin) fenvalerate

(Pydrin), or permethrin (Pounce or Ambush). Given that Unity Farm is home to 250,000 bees,

we want to avoid the use of bee toxins. BT is likely to be our best choice. We prefer crop rota-

tion, using resistant varieties, biological control, and use of row covers. Row covers are tricky

because they must be removed for pollination. We believe that planting early in the season

before the arrival of imported cabbageworm plus the use of row covers until flowering, should

significantly reduce losses.

Diseases

Diseases per the literature (Fritz) include black rot, black leg, club root, black leaf spot and gray

leaf spot, and downy mildew. We have not experienced these diseases.

In general, the best approach to brassica disease control includes a three-year crop rotation

schedule, avoiding irrigation runoff from infected to clean fields, controlling weed and insect vec-

tors, working in fields only when plants are dry, planting only disease-free seed.

inspecting transplants before field planting and disinfecting equipment used in the field if dis-

ease is present.

Local farmers have experienced the same issues as Unity Farm - imported cabbageworm.

They have used IPM methods which to them means application of pesticides several times dur-

ing the growing season. Since their scale is much greater than Unity Farm, row covers would

be challenging. We hope our small scale barrier methods will be successful.

Curcurbits (Cucumber, Pumpkin, Squash)

We grow several different varieties of English and Japanese cucumbers in the hoop house. We

grow pumpkns/summer squash/winter squash in mounds of alpaca manure on flat ground in

the orchard. Although we have had good yields of curcurbits, we have significant dieback in

midseason due to to cucumber beetles and squash bugs.

Pests

Major insect pests per the literature (Sanchez) include seedcorn maggot, cucumber beetles,

squash vine borer, squash bug, aphids, two-spotted spider mites, and white flies. Row covers

are effective against beetles, vine borers, and squash bugs, but they must be removed during

flowering to allow for pollination.

Striped cucumber beetles invade soon after transplanting and lay eggs at the base of plants.

The hatching larvae feed on the roots of cucurbits, pupate, and then emerge as new adults in

about 25–30 days. Row covers can be effective if applied at transplanting. Also, in order to

repel cucumber beetles, the cucumber cultivar should be genetically bitter free.

Squash bugs eggs hatch in 1–2 weeks, with young squash bugs feeding on plants for 5 weeks

before becoming adults. Control is achieved by trapping out adults, repeatedly inspecting lower

leaf surfaces, and removing eggs and young squash bugs.

Local farmers have sprayed permethrin to control these pests. We will attempt barrier/physical

methods.

Diseases

Per the literature (Sanchez), diseases are powdery mildew, downy mildew, bacterial wilt,

viruses, leaf Spots, fusarium wilt. Because of our significant cucumber beetle problem, we

have experienced bacterial wilt. The disease is characterized by the wilting and drying of indi-

vidual leaves. The leaves may wilt and recover during the night several times before finally dy-

ing, which has been our experience.

Local farmers who have controlled their cucumber beetle population have not experienced the

same issues. We believe our pest problem has caused our disease problem.

Lettuce

At Unity Farm, our 150 animals enjoy year round meals of romaine, winter density, and green

towers lettuce. We grow these using row covers in Spring and Fall. During Summer, we re-

duce our lettuce crops to avoid the bolting that occurs during the peak of Summer heat. We

have never experienced pest or disease problems with our lettuces.

Pests

Per the literature (Seamen), pests are aphids, aster leafhopper, cabbage looper,tarnished plant

bug, and northern root-knot nematode, Each of these is addressed by using resistant vari-

eties, cultural controls, biological controls, chemical controls, and post-harvest plowing ,

Diseases

Per the literature (Seamen), diseases are anthracnose, botrytis gray mold, bottom rot/wirestem,

damping-off, downy mildew, drop, aster yellows, and lettuce viruses, Many of these are ad-

dressed using appropriate humidity controls and ventilation.

Like us, local farmers using hoop houses and row covers have not experienced issues with let-

tuce pests or diseases.

Carrots

Unity Farm grows several varieties of japanese carrots and has not experienced pest or disease

other than occasional vole damage which is mitigated through the use of live traps (and release

of the animal)

Pests

Per the literature (Seamen), pests include aster leafhopper, aphids, carrot rust fly, carrot weevil,

and northern root-knot nematode.

Diseases

Per the literature (Seamen), diseases include aster yellows, leaf blights, cavity spot, rhizoctonia,

sclerotinia and white mold.

Per local farmers, carrots seem to be quite successful and disease free as long as an appropri-

ate site is selected that contains well drained, sandy soil.

Chenopodiaceae (Swiss chard, beets, spinach)

Unity Farm grows swiss chard year round for human and animal consumption. First plantings

are started in late Winter and the last plantings are started in late Fall. We have not experi-

enced any losses due to pests or disease but we do have to harvest in a timely way to avoid

Summer bolting and Winter frost damage.

Pests

Per the literature (Umass Amherst) pests include leafminer, cabbage looper, blister beetles,

and aphids.

Disease

Per the literature (Umass Amherst) , diseases includes cladosporium leaf spot, downy mildew,

seed decay, white rust, and cucumber mosaic virus.

Like us, local farmers have not experienced significant pest or disease issues with these crops.

Solanaceae Family (Peppers, Eggplant, and Tomatoes)

Peppers

Unity Farm grows wax peppers, jalapeno, and japanese peppers. The only damage occurs

because of slugs that consume peppers touching the soil.

Pests

Per the literature (Cornell), aphids and borers are the major problems. Natural predators such

as lady beetles are effective against aphids.

Diseases

Per the literature (Cornell), important diseases include cucumber mosaic virus and blossom

end rot matter. These are addressed by controlling pests and managing moisture.

Local farmers have had very few pests and diseases affecting peppers, mirroring our experi-

ence

Eggplant

Unity Farm grows Japanese eggplant. Flea beetles have been a major problem in the past.

We believe they can be addressed through the use of row covers.

Pests

Per the literature (Cornell), aphids, flea beetles, colorado potato beetles, and cutworms are is-

sues. Barrier methods can reduce the impact of flea battles and cutworms.

Diseases

Per the literature (Cornell), verticillium wilt is the most serious disease of eggplant and can be

avoided through crop rotation.

Local farmers do not grow eggplant, so we have no basis of comparison.

Tomatoes

Unity Farm produces large quantities of roma tomatoes which are sun dried. The only pests

have been tomato hornworms, which are fed to the ducks. Disease issues have been minimal

as long as crop rotation, ventilation, moisture management, and healthy cultivars are used.

Pests

Per the literature (Cornell), tomato hornworms, aphids, whiteflies, colorado potato beetle, cut-

worms and flea beetles are issues.

Diseases

Per the literature (Cornell), blossom end rot, catface , early blight, septoria leaf spot, late blight,

fusarium wilt , and verticillium wilt are issues.

Local farmers agree that tomato production in local hoop houses is successful as long as mois-

ture is managed, soil is amended with appropriate nutrients, and cultivars are selected appropri-

ately.

Asparagus

Unity Farm has two 50 foot asparagus beds, dug into a hillside and built up over the past 2

years. We have not yet harvested to enable foundational growth but will harvest next year. We

have not experienced any pests of disease.

Pests

Per the literature (Cornell) Asparagus beetles are issues. These can be manually removed.

Diseases

Per the literature (Cornell) fusarium wilt and crown rot are issues. These can be addressed by

not over harvesting and by destroying diseased plants.

Local farmers do not grow asparagus so we have no basis of comparison.

Discussion

In general, local farmers in Sherborn (Halamka) attempt to minimize the use of pesticides and

herbicides in an effort to reduce environmental impact, minimize cost, and produce a healthy

product. For all the produce listed in this paper, they employ a few basic principles:

Select sites with appropriate soil conditions and rotate crops seasonally

Plant resistant varieties when possible

Use natural enemies of pests

Make weekly scout visits and formulate recommendations for pest control

Clean up debris post harvest then apply compost and cover crops to benefit soil health and pro-

duction.

Keep equipment clean to avoid spreading infections.

Local farmers produce similar crops to Unity Farm as follows

June-July: lettuces, spinach, swiss chard, summer squash, zucchini, and cucumbers

August-September: tomatoes, pepper, summer squash, lettuce, carrots,, lettuce, broccoli,

cauliflower,

October:, tomatoes, peppers, broccoli, carrots, winter squash, brussel’s sprouts, lettuce, pump-

kins.

Local farms are diversified so that failure of one specific crop will not significantly impact their

business.

Conclusion

The terms IPM and Organic can be interpreted to mean different things to different farmers. At

Unity Farm, we will attempt to use no spray/low spray approaches to each pest and disease we

encounter, preferring to use the techniques summarized above in the discussion section. Our

crop failures in the past occurred because we did not prevent pest/disease issues nor dd we

rapidly identify and correct them when they occurred. That will change in 2016.

References

1. Journal of Agricultural Science, Cambridge (1997), 128, 59–71. 5 1997 Cambridge University Press 59

2. James R. Myers, W. Michael Colt, and Marilyn A. Swanson, Beans and Peas, http://www.-cals.uidaho.edu/edcomm/pdf/PNW/PNW0495.pdf

3. Vincent A. Fritz, Carl J. Rosen, Michelle A. Grabowski, William D. Hutchison, Roger L. Becker, Cindy B.S. Tong, Jerry A. Wright, and Terry T. Nennich, Growing broccoli, cabbage and cauliflower in Minnesota, http://www.extension.umn.edu/garden/yard-garden/vegetables/grow-ing-broccoli-cabbage-and-cauliflower-in-minnesota/#weeds-and-pests

4. E. S. Sanchez, Growing Cucurbits, Pennsylvania State University, http://extension.psu.edu/plants/vegetable-fruit/production-guides/vegetable-gardening-1/Cucurbits.pdf

5. Abby Seaman, Organic Production and IPM Guide for Lettuce, NYS IPM Publication No. 136

6. Xin Zhao and Edward E. Care, Influences of Organic Fertilization, High Tunnel Environment, and Postharvest Storage on Phenolic Compounds in Lettuce, HORTSCIENCE 42(1):71–76. 2007.

7. Abby Seaman, Organic Production and IPM Guide for Carrots, NYS IPM Publication No. 133

8. University of Massachusetts Amherst, https://nevegetable.org/crops/spinach

9. Growing garlic http://www.gardening.cornell.edu/homegardening/scene568b.html

10. Growing peppers http://www.gardening.cornell.edu/homegardening/scene9c8a.html

11. Growing eggplant http://www.gardening.cornell.edu/homegardening/scene26b5.html

12. Growing tomatoes http://www.gardening.cornell.edu/homegardening/sceneea10.html

13. Growing asparagus http://www.gardening.cornell.edu/homegardening/scenee3ed.html

14. Dodson, Mardi, Organic Greenhouse, Tomato productionhttp://www.slideshare.net/ElisaMendelsohn/organic-greenhouse-tomato-production-9580443

15. John Halamka, Interviews conducted at local farm stands in Sherborn, Massachusetts dur-ing November and December 2015 included Sunshine Farm, Dowse Orchards, Sweet Meadow Farm, and informal discussions with several non-commercial local growers.