Simply Sustainable

	Broccoli, planted in rotation with strawberries, helps reduce soil-borne pathogens, a critical alternative as regulators ban chemical fumigants. Plants That Battle Pests Alternative crop rotations supplant pesticide use Strawberries and broccoli make an unappetizing combination, unless you’re a California strawberry grower. Strawberries for fresh and processing markets are harvested from nearly 24,000 acres in California, accounting for 80% of U.S. production and a farm gate value of more than $600 million a year. Trouble is the fumigant long used to control soil-borne pathogens —methyl bromide—comes off the shelf in 2005, leaving producers with limited pest control options. Krishna Subbarao, a plant pathologist at the University of California Davis, sought to remedy that by exploring how rotating strawberries with broccoli, cauliflower, Brussels sprouts and lettuce would impact strawberry yield and disease incidence (SW99-009). Broccoli stole the show. Even though growers sacrifice a year of strawberry production to broccoli, the system is profitable over the long run. “Rotations with broccoli are likely to play a significant role in the post-methyl bromide era,” says Subbarao, adding that he’s talked to many strawberry growers contemplating broccoli rotations. Wyoming sugar beet growers have found a nematode-fighting ally with certain varieties of radish and mustard inserted into rotations as trap crops, a benefit multiplied when grazing lambs are added to the mix (SW97-018). David Koch, UW extension agronomist, found that growing “trap crops” increased grower returns to 5.8% from 3.9% with nematicides. The returns rose to 9.5% when lambs grazed the mustard and radish. The trap crops reduce pesticide use, cut the cost of beet production and may improve profitability through a rotation effect, says Koch. Radish and mustard planted in rotation with sugar beets not only reduce pesticide use but may also improve yields John McHugh of Crop Care Hawaii tested the trap crop method with Hawaii vine ripe tomatoes (SW97-001). He planted Sunn Hemp and yellow mustard cover crops to test their effects on reniform and root knot nematodes. The cover crops were at least as effective as soil fumigants and offered the added benefits of stemming wind and water erosion and restoring soil organic matter. Also in Hawaii, UH agronomist Susan Miyasaka is developing green manure cropping systems to control nematodes and fungal diseases in dryland taro (SW03-003). With the banning of methyl bromide, taro growers could see losses as high as 90% without a new alternative. To help Washington potato growers cut fumigant expenses, Andy McGuire of WSU is testing a mustard crop plowed down as a green manure for its nematode-battling value (SW03-018). Success would help slice fumigant applications that typically cost $250 an acre.   “SARE has helped to make the term ‘sustainable practices’ known to far-reaching areas beyond farms and agriculture. Only through education and ‘doing’ can this awareness of sustainability be promoted to preserve our land, water, natural resources and quality of life for future generations.” Susan Matsushima, president, Alluvion Inc., Haleiwa, Oahu, Hawaii Simply Sustainable Home Top