Maine Organic Farmers and Gardeners Association
Oilseed Radish
Oilseed Radish. English photo.

Oilseed Radish as Cover Crop

As a cover crop, the extra-long taproot of oilseed radish breaks up and aerates soil and draws up nutrients for following crops. It also suppresses weeds; and, when turned under just before flowering, its decomposition helps control soil-borne pests, especially cyst and sting nematodes. Hardy to 20 degrees, oilseed radish can be sown from early spring through summer at a rate of 2 pounds per 1,000 square feet. Avoid using oilseed radish in close rotation with cole crops, because they have similar pests and diseases. This planting was grown at MOFGA’s Trial Gardens in Unity from seed donated by Johnny’s Selected Seeds.

– Eric Sideman, MOFGA

Mustard Meal Tames Weeds

Agricultural Research Service (ARS) studies suggest sinalbin and other compounds released into soil by applying white mustard seed meals can kill or suppress some weedy grasses and annual broadleaf weeds. Agronomist Rick Boydston (ARS Vegetable and Forage Crops Research Unit, Prosser, Wash.) and plant physiologist Steven Vaughn (ARS National Center for Agricultural Utilization Research, Peoria, Ill.) evaluated the effects of three mustard seed application rates: 1/2, 1 and 2 tons per acre. The 1- and 2-ton rates worked best in peppermint, reducing barnyard grass, green foxtail, common lambsquarters, henbit and redroot pigweed populations by 90% several weeks after application.

Young peppermint plants sustained minor damage from the treatment but recovered and resumed normal growth. The treatment at all rates severely damaged onions when applied before emergence or before onions produced two true leaves. Applications at the two-leaf stage or later were more promising.

In trials with potted rose, phlox, coreopsis and pasque flower, the treatment killed or reduced growth of annual bluegrass, common chickweed, creeping woodsorrel and liverwort. In treated plots, 86 to 98% of common chickweed seedlings died; survivors were shorter and weighed less than treatment-free chickweed seedlings.

The researchers also evaluated the weed-control effects of field pennycress seed meal, and of dried distiller grains (DDGs) derived from corn ethanol production. Like white mustard, field pennycress has potential as a biodiesel crop. It and the DDGs were less effective than white mustard at controlling weeds. (“Scientists Serve up Mustard Meal to Tame Weeds,” by Jan Suszkiw, USDA Agricultural Research Service News Service, Dec. 2, 2008;

Transplants You May Have Not Considered
by Paul Betz, Commercial Grower Sales, High Mowing Seeds

Many farmers are aware of the benefits of transplanting sweet corn, including an even stand, avoiding crows and seed corn maggot damage, and getting an earlier crop. When I tell people we transplant green beans, a lot of eyes roll back. Beans are a little extra work, and they take up valuable room in an already cramped greenhouse, but I can’t imagine not transplanting them every year. Anyone who is selling at a farmers’ market can appreciate the value of having the “new thing” as early as possible. By bringing beans to the market very early, we get more stops at our stand and a better price.

We start ‘Provider’ bean seedlings about two weeks before they are direct seeded in the field, putting two seeds to the cell in a 50-cell flat. We plant them out after the first true leaves are full. Seedlings tend to be very tender and should be adequately hardened off. We transplant 5” apart within the row, and we use three rows in a 48” bed and then hoop and cover seedlings with AG-19 row cover. We space seedlings farther apart than seeds because transplanted bean plants get so much larger. We transplant three times, one week apart, and direct seed at the same time for a continuous supply.

Beets and spinach can also be transplanted for an early presence at the market. Spinach varieties ‘Tyee’ and ‘Samish’ work well. For beets we use ‘Early Wonder Tall Top’ or ‘Red Ace,’ but other standard varieties perform well. These crop types are planted in 128-cell flats, two seeds per cell, about three weeks before our typical direct seeding date. We transplant on the same day as our first seeding in the field. Transplants are set 4” apart within the row, with four rows to a 48” bed, and are covered with AG-19 row cover, although we don’t generally hoop them. We ensure, however, that the cover is loose enough for the plants to push up as they grow. The row cover also hides the crop from deer.

Including these plantings in your farm will give you earlier produce for a better price, without the expense of a high tunnel, and your customers will be excited to be eating healthy local foods after a long winter. (The Seed Bin, March 2008, High Mowing Organic Seeds,

Hops Vs. Clostridium in Chickens

Hops contain substances that control pathogenic bacteria in the intestines of chickens, say Agricultural Research Service (ARS) personnel. Certain bacteria in the intestines of chickens can contaminate meat during processing and may pose major production losses by causing disease in broiler chickens.

Many [non-organic] poultry producers use sub-therapeutic amounts of antibiotics in poultry feed to promote growth and to control bacterial pathogens or parasites. However, bacteria can become resistant to the antibiotics, so ARS scientists are seeking alternatives.

The hop plant (Humulus lupulus) contains bitter acids that are potent antimicrobials. One, lupulone, was thought to control levels of the disease-causing agent Clostridium perfringens in chickens. When ARS scientists and hops producer Hopsteiner in Yakima, Wash., fed lupulone via water to broiler chickens inoculated with C. perfringens, C. perfringens counts were reduced 30 to 50% compared with those of untreated chickens. (“Hops Extract May Reduce Clostridium in Chickens,” by Sharon Durham, USDA Agricultural Research Service News Service, Oct. 29, 2008;

New Hairy Vetch Varieties Flower Earlier

The Agricultural Research Service (ARS) has entered into licensing agreements with four seed distributors interested in marketing new hairy vetch varieties developed by an ARS scientist and cooperators. Hairy vetch is a common fall-planted cover crop that lies dormant over winter and flowers in the spring. It can be tilled into soil or rolled onto the soil surface, leaving a protective mat to hold moisture, prevent weed growth and curb erosion.

Using traditional breeding techniques, ARS geneticist Tom Devine developed two new varieties, ‘Purple Bounty’ and ‘Purple Prosperity,’ that are hardier and flower earlier than traditional varieties, adding up to two weeks to the growing season for corn, tomato, pumpkin and other summer crops.

Organic farmers have been using hairy vetch for decades because it adds nitrogen to the soil without the use of synthetic fertilizers. The new varieties allow farmers to grow earlier-flowering vetch as far north as Ithaca, N.Y. The plants may also be attractive to conventional farmers because they halve the need for synthetic fertilizers, which are made using expensive natural gas. (“ARS Licenses Hairy Vetch Varieties,” by Dennis O’Brien, USDA Agricultural Research Service News Service, Nov. 14, 2008;

Agroforestry Can Supplement Farm Income

Considering Christmas tree farming? University of Kentucky Forestry Professor Deborah Brooks Hill suggests small plantings of 200 to 500 trees with intercrops. This diversity should support beneficial organisms and reduce pest problems. Possible intercrops include alternating Christmas tree rows with rows of nitrogen-fixing black locust (with two rotations of Christmas trees during the 14 or so years required to grow locust fence posts), or floral crops such as corkscrew willows, red and yellow twig dogwoods and pussy willows. Christmas trees retail for about $25 to $50 each. (“Agroforestry can be sustainable source of supplemental income,” by Carol L. Spence, Univ. of Kentucky press release, Nov. 21, 2008;

Pecan Growers Can Benefit from Organic Systems

Researchers with USDA began transitioning a 20-acre, 27-year-old, conventionally managed pecan orchard to an organic system in 2002. The organically treated site out-yielded a conventionally managed, chemically fertilized orchard in each of the past five years. The conventional system would gross about $1,750 per acre, while the organic system would gross $5,290 per acre. (“Pecan Growers Boost Revenue by Growing Organically,” by Alfredo Flores, USDA Agricultural Research Service News Service, Nov. 4, 2008;

Pennycress Yields Oil and More

The annual winter weed field pennycress may yield an oil-rich seed for use in making biodiesel and an organic fertilizer and natural fumigant. USDA Agricultural Research Service research shows that an acre of field pennycress can yield 1,500 to 2,000 pounds of seed and potentially 75 to 100 gallons of biodiesel. The crop can be grown over winter and harvested in late spring, followed soybeans and, the next year, corn. Researchers will test the biodiesel refined from the crop to see if it meets industry standards for performance. The leftover seed meal may be useful as a soil fumigant. (“Experimental Plots of Pennycress Tested for Biodiesel Potential,” by Jan Suszkiw, USDA Agricultural Research Service News Service, Nov. 26, 2008;

MOF&G Cover Spring 2009
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