Abstract: ( Session 3) Strategies and Tactics Currently Used by Organic Farmers

Eric Sideman, director of technical resources for the Maine Organic Farmers and Gardeners Association, said there are four major strategies used for pest management: crop rotation, barriers, microbial insecticides, and botanical insecticides.

  • The success of crop rotation depends on how long a pest persists in the field, how capable it is of invading from other areas, and how well it survives on alternate hosts.
  • Floating row covers are used as a barrier to insect pests on several crop species.
  • Bacillus thuringiensis is the most commonly used microbial insecticide, but many more are in development.
  • Botanical insecticides are acceptable to organic growers because of their long history and rapid breakdown, but most certifiers allow them only as a last resort. Rotenone and pyrethrum are the most commonly used.

Insect Control Strategies Used by Organic Farmers in New Jersey

Emily Brown Rosen, formerly technical director for the Northeast Organic Farming Association of New Jersey, said that preventing pests through crop rotations, a good soil fertility program, an ample supply of water, and crop timing are important. Problem insects which may require intervention are:

  • Flea beetles on arugula: controlled by timing, growing under cover, or one or two sprays of rotenone
  • Cabbage worms: controlled with Bacillus thuringiensis
  • Stink bugs on solanaceous plants: rotenone
  • Tomato fruitworm: botanical insecticides
  • Colorado potato beetle: Bacillus thuringiensis, long rotations
  • Cucumber beetles: a single spray of rotenone followed by row covers.

Best Bug-Outs from West Virginia

Myra Bonhage-Hale, an organic farmer from West Virginia, collected techniques and home remedies from her fellow farmers and from an herb conference. As in previous accounts, the growers relied on soil improvement, crop rotation, row covers, and Bacillus thuringiensis. Diatomaceous earth and soap sprays were used against small, soft-bodied insects. Some growers used augmentative releases of biological control agents, either by collecting local populations or buying commercially available insect parasitoids.

Some of the herbs used for pest management were: rhubarb, garlic and hot pepper sprays, pennyroyal, sage and thyme. Pennyroyal extracts and essential oils of herbs should be used with caution because they can cause injury in high concentrations.

Discussion: Session 3

Someone in the audience asked about the extent to which farmers are buying and using beneficial insects. Purchased beneficials are used more often in the greenhouse than in the field, though some growers use Trichogramma against European corn borer and others use Pediobius against the Mexican bean beetle.

Another person in the audience asked about methods farmers use to track degree-days and insect development in order to time planting and other field operations. Some use information from Extension offices and others used observations of development of indicator plants around their farms.