Organic Cropping Research – 2007 Annual Report

Through its Biologically Intensive and Organic Agriculture (BIOAg) Program, the Center for Sustaining Agriculture and Natural Resources (CSANR) at Washington State University provided special grant funding for Organic Farming Research at WSU. This effort is part of a larger BIOAg initiative and is providing key research support for the expanding organic sector on high priority issues in organic crop production. The demand for research support for organic farming projects far outstrips the available funding from this and other sources.

In 2007, CSANR BIOAg provided $180,000 for organic agriculture research projects. The main objectives were organic seed protection and production, understory management in tree and vine crops, organic pest control, testing efficacy of materials, and economics/statistics on the organic sector. Progress reports from the 11 projects funded by this grant during 2007 are included in this report. The funding has provided opportunities for 4 graduate students at WSU to be involved in the research, an important benefit from this investment.

Progress Summary

Objective 1. Organic Seed.

Four specialized compost teas with very different microbial communities were tested for their effects on Xanthomonas, both on infected seed and in culture studies at WSU Pullman. Significant progress was made toward creating and characterizing defined teas of known microbial make-up. State approval of compost teas as an exploratory pesticide is needed, along with more laboratory and greenhouse tests, prior to field trials. The classification of compost tea as a pesticide has changed the view of this work to a more ecological study of microbial broth and changes to the existing microbial population of seed (spermosphere) and leaf (phyllosphere). An evaluation of seed and drench treatments for management of soilborne diseases for organic vegetable production was conducted. Efficacy of treatments was evaluated in the greenhouse against each pathogen using spinach. Selected treatments were further evaluated under field conditions and although there was variability in results among field trials, the Experimental II and X seed treatments consistently caused earlier emergence than other treatments at two sites, and higher emergence and lower disease at one site. The winter wheat breeding program at WSU Pullman has developed, evaluated, and identified advanced and heirloom wheat lines that are especially suitable for organic systems. Traits for weed competition, disease resistance, and nutrient uptake were identified in wheat varieties that are being used in this breeding program. Four years of yield and quality data on advanced wheat breeding lines will be merged with evaluations of weed suppression ability, disease resistance and nutritional value. At that time the variety release process will begin for: 1) germplasm of lines with high levels of certain traits important to organic farming, and 2) varieties adapted to organic farming systems in Washington State. In 2007, 15 early icebox watermelon varieties were evaluated at 3 diverse locations in Washington, Vancouver, Mount Vernon and Pullman. Variety performance varied by location; however, brix (measure of sweetness) did not vary and all varieties attained good readings at all locations. Farmers and consumers indicated high market potential for small fruit size, either personal/mini size or small icebox, and for red, yellow, and orange fleshed fruit. At WSU Vancouver REU, 17 butternut squash breeding lines from the Organic Seed Partnership national project (Molly Jahn, breeder) were evaluated along with 6 standard market varieties. Preliminary market studies throughout Washington indicate a good niche market potential for two mini entries, and we have requested the breeder to release them.

Objective 2. Pest Control.

Research at WSU Puyallup suggests that relay-planted cover crops are effective for weed management. A 50:50 rye-hairy vetch blend planted by early October yielded significant biomass and N benefits, and new research will focus on quantifying N benefits. Eight degradable mulches including papers, cornstarch, and degradable plastics were tested in an organic vegetable system at WSU Vancouver. There was little significant difference in crop yield due to mulch product. The most durable cornstarch and paper products were significantly less durable than black plastic after early August. The biodegradable plastics performed as well as black plastic, but did not break down acceptably in the soil, and are not allowable for certified organic production. Three biologically derived nematicides were tested in an established organic apple orchard and a conventional apple orchard in Washington, with some observable growth response after 3 years. In the organic orchard, nematicides appeared to reduce the lesion nematodes in two of three rootstocks, however gopher damage was significant throughout the orchard and interfered with measured parameters. In the conventional orchard, applications significantly decreased lesion nematodes without reducing the free living beneficial nematodes, and increased fruit yield.

Objective 3. Understory Management in Woody Perennial Crops.

In research at WSU Wenatchee, trials compared tillage, wood chip mulch, and “living mulch” cover crop techniques to a bare ground fertilized and unfertilized control in a newly planted orchard. Wood chip mulch led to tree growth and fruit yield that were similar to tilled plots, but resulted in poor weed control and tree nitrogen. Tillage provided good weed control and tree performance, but soil quality was measurably degraded by the second year. Living mulch species provided excellent weed control, but were too competitive with trees, and enhanced vole activity. The Sandwich system led to acceptable tree growth but poor fruit yield in Year 3. The Sandwich treatment with sweet woodruff (Galium odoratum) had significantly less vole activity than the other cover crop treatments, suggesting a potential to repel voles due to its coumarin content.

Objective 4. Economic Trends.

Profiles of organic production in Washington and Oregon were completed for 2006, and are available on-line as word documents and as powerpoint presentations. Crop data was not provided by Idaho State Department of Agriculture (ISDA) for 2006. We cooperated with the organic tree fruit packers to estimate the rapid growth potential of organic apples, pears and cherries. Statistics on organic feed and dairy needs were developed to meet a potential feed shortage identified by organic dairy farmers, in hopes of inducing new growers to produce organic feed crops. The prices for Washington organic apples and pears were analyzed using the sales data from November 10, 2003 to August 28, 2006, organized by the Wenatchee Valley Traffic Association, the most complete dataset available for Washington apples and pears. Major apple varieties, Red Delicious, Golden Delicious, Fuji, Gala, and Granny Smith, and pear varieties, D’Anjou, Bartlett and Bosc, were analyzed. Apples and pears appear to be sold at similar price levels but price variation is larger for apples. Both apple and pear prices are highly seasonal, with those from regular storage having a price drop and those from controlled atmosphere storage having a price increase in early summer.

Objective 5. Efficacy of pest management and fertility materials.

A number of available and potential products were evaluated, and all are described under objectives 1-3.

Specific Projects in 2007

  1. Evaluation of seed and drench treatments for organic production
  2. Control of Xanthomonas in cabbage seed
  3. Cover crops for weed management in organic and transition systems
  4. Economic trends in organic production
  5. Understory management in organic tree fruit crops
  6. Late blight management in organic potato production
  7. Evaluating and devloping wheat varieties for organic systems
  8. Food safety needs assessment for sustainable agriculture producers in WA
  9. Alternative mulches for weed control in vegetable production systems
  10. Evaluating vegetable varieties for organic systems
  11. Post-plant management of nematodes in apple orchards in WA
  12. Nitrogen supply and partitioning in managed understories of organic apples
  13. Market Price Analysis for Washington Organic Apples and Pears