Abstract: Small Group Session - Solanaceous Crops (Potatoes, Tomatoes, Pepper, Eggplant)
Living Straw Mulch for Suppression of Colorado Potato Beetle (Leptinotarsa decemlineata)
Eero Ruuttila, an organic farmer from New Hampshire, had such a severe problem with Colorado potato beetles that he could not grow potatoes organically. He heard that straw mulch had interfered with early season Colorado potato beetle activity in the south , and he began experimenting with growing his mulch next to his potatoes instead of bearing the cost of bringing it into the field. His experiments showed that potato plants that were planted in a field of overwintered rye and hairy vetch and covered with the mowed rye had very little beetle activity early in the season, and produced a yield similar to potatoes treated with timely applications of Novodor, an effective
Bacillus thuringiensis (Bt) product.
Based on these results, Eero has developed a system that first reduced spraying to a single Bt spray per year, and now has allowed him to eliminate all spraying for Colorado potato beetle. It involves crop rotation, planting into a winter cover crop of rye or rye and vetch, alternating 5-foot tilled strips and 5-foot strips of cover crop, and then mowing the cover crop and blowing it onto the plants in a timely way before the adult beetles move into the rows.
Evaluation of Five Organic Techniques of Controlling Flea Beetles on ‘Kennebec’ Potatoes
Myra Bonhage-Hale, an organic farmer from West Virginia, compared applications of hot pepper spray, dusting with lime, applying vitamin E, applying mixed vitamins, and using row cover (Reemay) in controlling flea beetles on potato plants. Flea beetle populations were low. The row cover and lime treatments had the lowest flea beetle numbers, but also the lowest yield. The control bed had the greatest yield.
Wild Predators Feeding on Two-Spotted Spider Mite (TSM) in Eggplant
David Stanley, an integrated pest management consultant in Massachusetts, found unusual two-spotted spider mite infestations in vegetable crops due to drought. He discussed conditions that made the spider mite infestations worse in some fields, including poor drainage early in the season that resulted in a Phytophthora outbreak and poor plant cover for the predators of the mites, and poorly timed applications of pyrethroid insecticides that killed mite predators.
Biological Control of Tomato Fruitworm with Trichogramma Wasps
Michael Hoffmann, an entomologist from New York, described the integrated pest management program for the tomato fruitworm, Helicoverpa zea, in California, and how the discovery that natural populations of Trichogramma were killing a large percentage of the eggs (up to 100% at times) was incorporated into the sampling plan and thresholds. This resulted in higher economic thresholds when parasitized eggs were present and reduced insecticide use.
Discussion: Solanaceous Crops
Eero Ruuttila gave further details of how he manages his cover crop and uses it to mulch potatoes. There were additional questions and comments about stink bugs on tomatoes, using essential oils against mites, wireworms, European corn borer on peppers, and biological control of aphids on peppers and tomatoes.