Organic Management of Diamondback Moth and Similar Insects

fresh cabbage

The diamondback moth is one of several species of moths and butterflies whose larvae feed on cabbage and related crucifers in New York. Plans to test a genetically engineered diamondback moth at the NY Agriculture Experiment Station in Geneva NY have been in the news recently. The genetically engineered diamondback moth was developed in England by Oxitec.

Researchers are studying if the introduction of the genetically engineered diamondback moths into fields where diamondback moths are naturally present is a way to reduce crop damage due to diamondback moth larvae. Caged trials of genetically engineered diamondback are being done and open field trials have been proposed. The proposed trials, especially the open field trials are controversial. There are many questions regarding the risks associated with releasing genetically engineered insects into the environment. Many people believe more needs to be learned about the potential impacts of releasing the genetically engineered moths before open field trials are conducted.

Organic growers – both small and commercial scale – have many tools in the toolbox to control these insects and limit the damage caused by the insect. In fact, organic and IPM methods when properly timed and used appropriately will do an excellent job in managing diamondback moth.

The most effective organic control methods rely on exclusion, like insect netting or row cover, or timely and regular treatment to ensure that populations do not increase. An IPM approach where sprays or other applications of materials are made once a threshold population level is observed is often effective. At low population levels, naturally occurring insects and parasitoids may be sufficient to control diamondback moth populations. Heavy rainfall has been observed to reduce larva and even well timed use of sprinklers simulating a heavy rainfall can reduce larval populations.

Where the crop is in its growth cycle also needs to be considered as the risk of significant crop damage changes as the crop grows. So, while it may make sense to treat a young crop if diamondback moth larvae are found in 10% of the crop or a certain number are found on a sticky trap placed in the field, later in the season, the threshold might be 30% or more before taking action.

Several varieties of parasitic wasps and flies have also been found to be effective. In addition, several OMRI approved materials have been found to work well if spraying is needed. Entrust and Dipel DF are both effective against diamondback moth and other larvae which could be present on the affected crop. These materials are also very specific and affect larvae feeding on the crop, but do not kill the beneficial insects which feed on the larvae. Pyganic is also labeled for diamondback larvae, imported cabbageworms and several other larvae which may feed on cabbage and related crops, but is a broad spectrum insecticide and will also kill many of the beneficials feeding upon the larvae.

Diamondback moth is not the only insect whose larvae feed on cabbage and related crucifers. In NY, cabbage loopers, imported cabbageworms and cabbage moths also have similar life cycles and feeding preferences. Organic control methods for these pests are similar. The life cycle for these pests is short, with several generations occurring each season. Several species may be present at any time in the field and with early prevention and monitoring, they can be successfully controlled using organic methods.

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Fungi and Bacteria and Viruses, Oh My!

Maryellen Sheehan, NOFA-NY’s Fruit and Vegetable Coordinator and co-owner of Hartwood Farm in Fenner, NY, shares with us some of her experiences growing organically in 2014, plus invites the organic producer community to learn together on October 21st.

After moving to NY from a high-elevation frost pocket in NH (average 95 days frost-free), I belatedly realized the sole advantage of a super short growing season—frost kills your plants before disease has time to off them!  Switching to farm in the lower Hudson Valley’s vaguely tropical 160 frost-free day season was both amazing (so many new crops to grow!) and educational (twice the warm weather hosts exponentially more insects and disease to kill plants!).

While my inner scientist remains fascinated by finding and identifying all the new plagues offing our plants at Hartwood Farm in Fenner, NY (new this year: Swede midge, bacterial spot, and the undetermined soil funk that melted 3 plantings of lettuce), the market farmer part of me does not enjoy these new discoveries.  The NOFA-NY technical assistance part of me dreads hearing about the challenges faced by some of our members this season, but that part of me is able to take action by planning educational events for growers who, like me, face all sorts of unexpected challenges each year.  At the end of each season, and throughout the winter, we have the opportunity to reflect on the diseases that impacted our community and learn what practices and controls are proving most effective.IMG_5721

We have dedicated researchers and educators committed to helping organic and IPM growers identify their problems and find effective control options.  On Tuesday, October 21st, Cornell’s Chris Smart, Abby Seaman, Meg McGrath, and Sarah Pethybridge will join up to teach organic management for bacterial and fungal pathogens, soil borne disease, and late blight.  It will be a full and informative day with plenty of time to ask questions—we hope to see you there!  There is no other way to get this small-group access to these great (and busy) researchers; at $25 for the full day, including lunch, it’s worth the day off the farm.  Register HERE or read the full workshop description HERE!

Why think about diseases now?  Since organic control options are based on prevention, now is really the best time to plan for potential problems!  In the heat of the summer, most of us won’t have the time to research and shop around frantically for last minute insect and disease controls.  In the mid-winter, a lot of the daily challenges have faded (and some of us even attempt to go on vacation, leaving less time to learn and plan).  During the late winter and spring, growers are busy enough going to conferences and conventions, seeding, planting, and doing a thousand other things, so it can be difficult to think about preventative sprays and staying on top of a disease control program.  It’s easier when you pre-program that into your schedule by planning for it before any of next season’s action.  Variety selection, field layout, and soil amendments all affect your crops as well, and you certainly need to account for all of that before you open those gorgeous seed catalogs in the winter.  Our instructors at both October events are planning to give great information about these strategies, from organically-approved sprays to soil-building for robust plants at our October events.

004For a little teaser about organic disease management concepts, UVM’s Vern Grubinger has a short article that really hits on the key points here: http://www.uvm.edu/vtvegandberry/factsheets/diseasemanagement.html.  There are often multiple pest, disease and climate-related concerns that confuse and confound farmers.  While a great resource to help learn disease identification is the Vegetable MD website: http://vegetablemdonline.ppath.cornell.edu/, I’d still recommend you come to our workshops with any photos, data, or questions about what you experienced this past season.  With many farmers and plant pathologists in one room, we’re bound to learn what’s trending in terms of organic production problems.

Hopefully these resources help you as you get started thinking about next year’s potential crop health challenges, and we hope to see you in Geneva on October 21st!

On October 30th, we’ll tackle many of the same issues, but hone in on some marketing and variety research as well, all related to the diverse and appealing Brassica plant family.

Fall’s Royal Crop: Growing, Selecting and Eating Storage Squash

Erik Fellenz weighs red kuri squashWith names that tend toward the fairy-tale (Cinderella, Moonshine, Black Forest, Hubbard, Carnival) to the exotic (Rouge Vif D’Etampes, Musque de Provence, Kakai, Red Kuri) to the downright confusing (Long Island Cheese Pumpkin, NutterButter, Pink Banana), the thick-skinned storage varieties of the Cucurbitaceae plant family (which also includes summer squash, zucchini, cucumbers, decorative gourds, chayote, and luffa gourds) represent a diverse and flavorful food source for us in the Northeast.  Many of us are accustomed to paying rock-bottom prices for pumpkins and gourds destined only for carving and decoration, and buying canned pumpkin off a grocery store shelf (organic canned pumpkin is available in this day and age, a nice alternative for the non-DIYers among us).  A conventionally-grown or imported pumpkin creates quite a toll on the environment, and builds a perception that all thick-skinned squashes, whether for centerpieces, Jack-o-Lantern carving, or eating, should be a cheap food.  Squash may not be as precious as baby salad greens at the start of the spring, or those heavy 3-lb heirloom tomatoes at summer’s peak, but growing flavorful, ripe squash at a small scale, without conventional pesticides and fertilizers, and in our unpredictable climate zone, causes farmers to either take a loss to bring us these colorful fall favorites at our expected price point, or ask a large price for something we’ve come to expect to be cheap.

While squash indeed grows in our region, and is prized for its nutritious flesh that keeps within a protective shell throughout the winter, our Northeast summers are not ideal for this plant to bear and set fruit.

Challenges and Strategies for Growing Winter Squash:

More days in the field means more potential for pest infestations, disease-producing conditions, weeds taking over, and mammals to munch leaves.

Other crops (including those high-priced greens and tomatoes) can’t be grown in a squash field for the whole spring-summer-fall season, an example of an opportunity cost.

Plenty of heat and sun (temperatures in the 80’s during the day and 60’s at night) are needed for squash to grow well.  With 2014 providing an excellent example, it’s clear that our climate doesn’t provide that consistently.  Growers have some management options here, including black plastic, Biotella biodegradable mulch, or dark landscape fabric (all of these help with weed suppression, too), a well-sited field with southern exposure, and starting the plants in a greenhouse or cold frame to have them maturing for more of the hot days of the year.

Squash are susceptible to moisture-borne diseases, namely powdery and downy mildew.  Variety selection and air circulation are key for crops, but no grower is immune to poor weather.  While some growers will provide cucumbers a drier environment in a high tunnel, this is not practical for the area of space and amount of time (again, it’s an opportunity cost, this time with expensive infrastructure) the pumpkins and winter squash require.  Disease-tracking reports are available to help growers be aware of the movement of disease via tropical storms.  Yearly crop rotation and proper disposal of infected plants help the chemical-free grower avoid future issues with these diseases.  Organic producers must always be on the preventative side, planning management tactics into their production plans, rather than wait for disease and pest problems that can be killed via non-organic methods.  If you’re interested in being such a savvy producer (of more than winter squash), attend the October 21st workshop in Geneva, NY, which will feature a number of experts in organic disease management!

Squashes need lots of soil fertility, so a grower needs to build soil for years prior to a planting of winter squash, and any crop that follows squash should be one that returns nutrients to the soil (like leguminous cover crops), or at least does not require a lot of soil fertility.  This long-term planning, and heavy use of resources outside of the actual growing year for the squash crop, makes the cost of production even higher than most farmers calculate.Joshua Levine (13)

Squash plants are spaced out significantly in the field to allow the roots to soak up nutrition, and the vines spread out to absorb the 3-4 months of sunshine that go into ripening each hefty, colorful, knobbly, lovable fruit.  Weeds can populate the between-vine and between-plant space and cause serious competition.  Cultivation and tillage when the plants are young might be one option for controlling weeds, but hand labor or deciding to not weed are the late-season options for weed control.  Growers use mulch to reduce the areas of the field where weeds can catch sunlight and flourish, and there has been some research into no-till methods of growing squash.  Conventional squash fields can be sprayed with certain herbicides to kill grassy weeds, and organic farmers can’t take that option.

Ripe squash fruits are heavy and require lots of labor and proper conditions to move from the field to storage, and from storage to sale.  Fair labor and living wages for farmers and their crew mean that squash harvest is pricey!  Squash must also be “cured” for 7-10 days at 80 to 85 degrees, meaning a grower must hope for late-summer/early fall heat waves or use up high tunnel and greenhouse space for curing.  A good storage facility for long-term storage has temperatures around 50 degrees and 60% relative humidity.  Beyond that, there should be good protection from rodents and the stock should be checked regularly for signs of storage decay, which can spread.

Further resources:

Enjoying and Eating Winter Squash:

pumpkins groupNow that you know the ways that your local farmer is working to bring you these great foods, you’re probably in the market for a few good techniques to prepare these squashes.  Some are better for certain applications, and your best bet is to ask a farmer about how watery/dry the flesh is, and how sweet/savory the flavor.

To roast small squash (Delicata, Acorn and Carnival varieties), you can split them stem-to-end, scoop out the flesh, and rub them with just a little fat, salt and seasoning (see below for ideas).  For larger varieties, peel and cut the squash into chunks or slices and massage with the oil and seasoning combination, then bake until tender.  Bake halves on a tray (line with parchment or foil, or just embrace the scrubbing you may need to do later) cut-side down in a 400 degree oven until you can pierce the skin with a fork and find soft flesh underneath.  Make a whole batch of roasted squash, and see all the ways that it can feed you.  Intact but cooked-through and chilled squash pieces even work well in salad, and any amount of cooked flesh can be dumped into simmering broth, then pureed into soup.

The drier fleshed squashes can be sliced very thinly and added to skillet sautees and even stir-fries (make sure they get good browning in a hot pan with oil, and that they cook through).

All squash will steam up nicely, cubed, sliced or chunked.  Keep an eye on it to keep it from disintegrating (use it for soups and better-than-potato mashes if you end up with too-soft pieces).  Pile some cooked beans and salsa atop, dress simply with olive oil, or add to a pasta dish.

A pressure cooker (assuming it’s the right size) makes quick work of halves and quarters of squash.  Just 10 minutes atop a steam insert is really all it takes.  Add some strong herbs into the steaming water for a lovely infusion of flavor.

Try these flavor combinations with squash:

  • olive oil, black pepper, garlic paste, and rosemary
  • sesame oil, maple syrup, and miso paste or soy sauce
  • butter, crushed fresh or dry sage, thyme and honey
  • olive or sunflower oil, crushed hot pepper or chile powder, cocoa powder (not cocoa mix), smoked paprika
  • coconut oil and curry powder or garam masala blends of spices
  • “Pumpkin Spice” mixes tend to include cinnamon, nutmeg, allspice, and cloves; they go well with butter
  • finish any of your squash dishes with chopped and toasted nuts or (appropriately) pumpkin seeds or something creamy

Make your own pumpkin puree (via Local Kitchen, the key is straining out lots juice from the cooked flesh, then it will act much like the canned type, but with local flavor!)

Variety guide (Co+Op)

See the ode to winter squash (and all Cucurbitaceae) in Deborah Madison’s Vegetable Literacy.

Tips for cutting the tough and dense raw fruits abound on YouTube: Soften the skin in hot water (Down to Earth Organic & Natural), navigating the butternut shape (Chef Tips), Use the microwave (CHOW)

More fun recipes: Pumpkin Spanikopita (Local Kitchen), Butternut Squash and Kale Beef Stew (Girl Meets Paleo), Red Kuri Creme Fraiche Pie (Co+Op), Roasted Winter Squash Salad (101 Cookbooks)

Seed Saving Can Save Us All

Last Thursday (9/25/14), our friends at Turtle Tree Seed led a field day of their seed-production farm and seed company based at Camphill Village-Copake.  About 30 individuals contribute to the management of the gardens, the harvesting and processing of mature plants to extract seed, the cleaning and sorting of seed, and the marketing and packaging of the final product.  Many of these individuals are residents of Camphill Village who have developmental disabilities, who have meaningful and fulfilling work thanks to the connection between Biodynamic Agriculture and the Camphill Village philosophy. The growers explained that to grow biodynamic seed, one simply grows the plants biodynamically (and organic seed comes from certified organic farms and plants).  Because of the length of time in the field (seed crops are generally harvested well beyond eating ripeness), any plant grown for seed will face much more disease and pest pressure; this is why organic and biodynamic seed production is so important for environmental health, and why all growers should consider supporting only organic and biodynamic seeds; conventionally-produced seeds have a heavy impact on the environment before they are even planted by a farmer or gardener because pests, disease, weeds and soil fertility can all be managed through chemical methods.  No matter the production philosophy or certification, one needs to isolate plant varieties in time and space if they are a crop that is likely to cross-pollinate (and therefore change the genetics of the seed produced).  Additionally, plants that are grown for seed also need much more room because they will grow much larger.

This is zucchini at a seed-mature stage.  Not exactly eating quality squash any more.  One would scoop out the inner flesh and clean the seeds using water and a scrubbing motion before drying and storing the seeds.

This is zucchini at a seed-mature stage. Not exactly eating quality squash any more. One would scoop out the inner flesh and clean the seeds using water and a scrubbing motion before drying and storing the seeds.

The group learned three different seed extraction methods: dry harvest, wet harvest, and fermentation/wet harvest.  Each technique involves taking the plant with fully mature seeds and separating the seeds from the rest of the plant, and cleaning out any immature seeds, making use of seed weight and seed size to help in the separation.  For dry-harvested seeds (where the plant has flowered and created a pod that dries out), one uses significant pressure to crush and break down the pod and plant parts, then winnows with air to separate off lighter-weight plant parts and debris, and finally passes the seed through a set of screens to filter out larger particles and long bits of stem.

Using a fan to winnow lettuce seeds.

Using a fan to winnow lettuce seeds. The heavier seeds land in the bin nearer to the fan, and the debris lands in the second.

For wet-harvested seeds (where the plant’s fleshy parts contain the mature seed), one has to open the fruit and remove the flesh and seeds.  In the case of cucumbers and tomatoes, the seeds are left to ferment for several days to break down a protective membrane around the seeds.  The seed saver uses a water winnowing technique for wet-harvested seeds.  Seeds and flesh are placed in a jar or bowl, and water runs on top.  Then water is poured off, and with it goes the non-useable part of the mixture, which floats to the top, and the heavy, mature seeds stay at the bottom.  After water winnowing, the seeds are spread on paper to dry.

Purple tomatillos after blending. This mixture will be filtered and water-winnowed.

Purple tomatillos after blending. This mixture will be filtered and water-winnowed.

Watermelon seeds are extracted by eating and spitting!  This variety is called Cream of Saskatchewan.

Watermelon seeds are extracted by eating and spitting! This variety is called Cream of Saskatchewan.

We learned how variety selection works in root crops, which take two seasons to set seed.  At Turtle Tree, the growers harvest mature (eating-stage) onions, carrots, etc. and sort them based on the varieties’ written descriptions.  The 25% that most exemplify healthy, true-to-type specimens will be grown for seed that becomes the future seed stock on the farm.  This helps ensure a purity in the variety for the long-term.  The middle 50% of the crop will be replanted in the second season, and its seed will become what is harvested for sale through the Turtle Tree Seed Company.  This is still a high-quality and true-to-type seed!  The bottom 25% of the crop (they do not exemplify the variety characteristics as well as the top 75%) is used as food in the community dining hall.  To account for differences in growing conditions, plants are harvested in very small batches and compared within their batch (then added to the graded piles).  That way, the grower can control for the fact that poor soil in that few feet of the garden bed impacted the shape and size of the carrots, for example.

carrot grading buckets poor good select carrot grading 2

While not every one of us will become seed farmers, it’s important to support the work of the companies who are preserving the range of plants and subtly-different varieties.  It takes more land and plenty of extra vigilance on the part of the grower, especially if the plants are being grown organically!  Here are a few other seed companies we know and love (and who have taught us about seed farming in the past):

seed grower to do list

Further Resources:

When Buttercups are Bad: Co-Pasturing Field Day at Wild Geese Farm

Nancy Apolito, our Finance & HR Manager, sends in this report about her recent adventure in Western New York, staffing a field day in Rushford, NY at Wild Geese Farm.  The field day’s theme was “Maintaining Pasture Systems to Meet Your Farm Goals.”

Lynn and Shawn Bliven pasture feed a herd of cattle, 5 horses, and 25 sheep in addition to housing a dozen chickens.  Lynn Bliven led the field day with a walk through four of the pastures to demonstrate the results of co-pasturing livestock.  Aaron Santangelo from Cornell Cooperative Extension–Allegany & Cattaraugus County provided valuable information regarding pasture plants that are harmful to livestock and the way that these plants propagate.  Farmers who know about the full lifecycle of these invasive can strategically manage their herds on pasture to avoid problems and sometimes alleviate the weed pressure using the animals’ inherent capabilities.

Bull Thistle

Canadian Thistle

Bull Thistle

Canadian Thistle and Bull Thistle grow and spread differently.  Bull Thistle needs two years to produce seed–it’s less aggressive when its life cycle is disturbed yearly by turning the soil, but it’s a problem in pastures since they are not tilled.  Canadian Thistle has underground growth that makes it problematic even in tilled fields.  I found out that even common plants, like buttercup, can be very dangerous to a herd.  Grazing behavior (as in, what to eat) should be taught to animals–they won’t know what is poisonous by instinct.  Older animals in the herd or flock can set the right example, and farmers should be careful to watch what the young animals are eating.  Lynn shared that she lost 15 sheep due to their grazing on a plant in the nightshade family.  Even wild rose can cause problems for the smaller animals.

The highlight of the afternoon for me was seeing the sheep and the cattle pasturing in separate areas. Lynn spoke of the differences in the pastures after the different herds have been grazing.  I was amazed at the difference (I don’t live on a farm, remember!) between the vegetation in the pastures, which was impacted by the physical size and shape of the different species.  One great way to deter invasive plant species is to allow cattle in to trample the plants down.  The sheep on pasture clip the field down farther than the cows want to and this maximizes the value of each pasture.

The pastures at Wild Geese farm have taken 17 years to reach this point.  Co-pasturing takes organization and each species requires different enclosures and management; Lynn also discussed some common problems with grass fed herds, weaning calves, and establishing healthy environments for many types of animals on a farm.  However, going this route has helped make the pastures more productive and the farm more profitable.

Lynn shared aerial maps and grids that help the farm plan out pasture schedules.  They’ve also used this tool to carry out a slight re-grading of the landscape and some drainage improvement projects.  This allows for animals to have access to high-quality pasture areas and a water source at all times.  Healthier animals will make for higher-quality meat and better returns for the farm!  My day was rounded out by two Red-Tailed Hawk and one Osprey sighting over the gorgeous landscape.

Further Resources:

Be Prepared for Late Blight (and other Leaf Disease!)

Our Fruit and Vegetable Coordinator, Maryellen Sheehan, shares very timely information about late blight, a serious disease affecting tomatoes and potatoes.  Gardeners and farmers alike should be careful to scout for and properly dispose of the infected plants.

These past few cool, wet weeks were unfortunately quite conducive to a host of foliar diseases. Keep an extra eye on your tomatoes and potatoes for signs of late blight in particular, which has been confirmed in parts of western, central and eastern NY, Long Island, and central PA.  A national map of confirmed late blight cases (and sample submission protocol) can be found at: http://www.usablight.org/map.

Late blight spores are airborne and move quickly. We generally see lesions on middle and upper level leaves, but key signs are when the moist looking, gray-brown lesions form on the plant stems and leaflets. On potatoes, the lesions can almost look greasy. Identification and scouting help can be found in E-Organic’s scouting video: https://www.youtube.com/watch?v=uCzIFVfyNow and NYSIPM’s video to help separate late blight from all of its imitators (this is also a bad year for early blight and other leaf funk): https://www.youtube.com/watch?v=aA4PuEKaQpY

Images courtesy of Meg McGrath and the Long Island Horticultural Information & Research Center

Images courtesy of Meg McGrath and the Long Island Horticultural Information & Research Center

If you find suspected late blight on your farm, please report it immediately to your Cornell Cooperative Extension Vegetable specialist (or through http://www.usablight.org) and find out how to send in a sample (it’s important to have these samples to see which race of blight is spreading this year).

The late blight pathogen comes on so fast, by the time it is found in a planting, it is often too late to save the crop. Preventative management, including pruning, wide plant spacing, trellising, and preventative sprays, is key to blight management. If you scout daily, catch an infection early, and have a lightly affected planting with good airflow and trellising, it might be possible to try and save the plants by starting off just removing any affected tissue and beginning a fungicide program immediately (remember to check with your organic certifier before using any products!). However, a widespread infection on heavy, lush plant growth will likely not be controllable. Late blight spores spread disease rapidly, so removing infected plants quickly helps prevent infection spread to neighboring plants (and your farming neighbors).

Additional late blight management articles can be found at:

http://www.mofga.org/Publications/MaineOrganicFarmerGardener/Spring2010/LateBlight/tabid/1555/Default.aspx
http://lateblight.nysipm.cornell.edu/
http://vegetablemdonline.ppath.cornell.edu/PhotoPages/Spin/Tom_Spin.html
http://lateblight.nysipm.cornell.edu/files/2011/08/Pot_LB_OrganicMgt10.pdf
http://www.longislandhort.cornell.edu/vegpath/photos/lateblight_tomato.htm