Organic Cropping Research – 2005 Annual Report

The Center for Sustaining Agriculture and Natural Resources (CSANR) at Washington State University has received special grant funding from USDA-CSREES to conduct the Organic Cropping Research in the Northwest program. This effort, a part of our larger BIOAg initiative (Biologically Intensive and Organic Agriculture), 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.

The organicfood sector in Washington State is estimated at over $200 million in annual value. Major elements include tree fruit production and packing, processed vegetables, herbs, direct market operations, grains, and livestock. With over 30,000 acres under certified organic management, the impact on agriculture is considerably wider as many growers utilize practices launched on their organic acres on their conventional fields as well.

In 2005, the CSREES special grant on Organic Cropping Research for the Northwest provided $335,208 to CSANR for research projects. These projects leveraged matching resources of some $180,000. 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 13 projects funded by this grant during 2005 are included in this report. The funding has provided opportunities for 5 graduate students at WSU to be involved in the research, an important benefit from this investment.

Progress Summary

Objective 1. Organic Seed.

Organic seed treatmentproducts were tested to evaluate their efficacy in protecting peas from damping-off and root disease. Seven different biological products were used in two field trials at WSU Mt. Vernon REC. Only pea seed treated with Serenade ASO had similar yield to the conventional treatment, while all other biological products were significantly less. A new graduate student has started work on a project to evaluate the efficacy of organic seed treatments for control of soilborne damping-off or seedling blight of fungal pathogens of spinach. A new project began that is evaluating compost tea for control of Xanthomonas bacterial black rot on cabbage seed. The first step was to develop reproducible microbial communities in the compost tea. Four contrasting types of teas have been developed: bacterial, fungal, protozoan, and high bacterial diversity. Molecular techniques are being applied to the microbial characterization. Working closely with farmers, the winter wheat breeding program at WSU Pullman is evaluating, identifying, and developing advanced and heirloom wheat lines that are especially suitable for organic systems. Research to date has established that there is little or no correlation between the ranking of varieties for yield between conventional and organic systems, thus indicating a need for breeding under organic conditions. In addition, potentially useful traits for weed competition, disease resistance, and nutrient uptake were identified in historical and modern wheat varieties that are being used to develop new varieties for organic systems. At WSU Vancouver REU, 80 out of 101 icebox watermelon varieties screened were suitable for organic systems. Hoophouses and cloches were used to screen 34 winter lettuce varieties. Most performed well and had good to very good flavor rating.

Objective 2. Pest Control.

Research on organictransition rotations for northwestern Washington was conducted at WSU Mt. Vernon. For 2005, mustard and winter rye/hairyvetch cover crops were the most effective in regards to weed control. An infrared flamer was better for postemergent weed control than various organic herbicides. Research at WSU Puyallup REC on cover crops for weed management in organic and transition systems suggests that relay-planted cover crops can be a viable option for organic growers for some crops and that hairy vetch and red clover are most effective at weed control, with planting at 4 weeks after the cash crop is planted. A 75:25 rye-vetch mix at planting led to a 50:50 rye-vetch biomass at harvest. Eight degradable mulches were tested in an organic vegetable system at WSU Vancouver REU, including papers and degradable plastics. The biodegradable plastics performed as well as black polyethylene, but did not have acceptable breakdown in the soil. Three biologically derived nematicides were tested in established apple orchards in Washington, with some observable growth response in the first year. These newly developed organic nematicides have the potential to decrease plant parasitic nematodes in organic apple orchards without affecting beneficial microorganisms in the soil. A new study evaluated control of carrot rust fly with Metarhizium anisopliae and Steinernema feltiae as biocontrol materials.

Objective 3. Understory Management in Woody Perennial Crops.

In research of understory management at WSU Wenatchee TFREC, mechanical tillage for weed control did not negatively impact tree growth or soil quality. The wood chip mulch provided the best weed control and provided an economically significant increase in fruit size. Living mulches in a new apple planting severely competed with the young trees, even with fertilizer injected into the root zone. Higher base fertilization did not overcome this problem either. Cover crops in the tree row dramatically increased presence of voles.

Objective 4. Economic Trends.

Profiles of organic production in Washington State and Oregon were produced for 2005. Initial data on organic apple prices were collected for use in examining price in response to crop sizes supplied to the market. An economic model has been constructed and will be tested with the initial data set.

Objective 5. Efficacy of pest management and fertility materials.

A number of available and potential products were evaluated in 2005, and all are described under objectives 1-3.

Specific Projects in 2005

(Titles link to the text progress report. PP links to the powerpoint presentation as a PDF file)

  1. Organic seed treatments.
  2. Control of Xanthomonas in cabbage seed. [PP]
  3. Evaluating and developing wheat varieties for organic systems. [PP]
  4. Evaluating vegetable varieties for organic systems.
  5. Organic transition rotations for Northwestern Washington.
  6. Cover crops for weed management in organic and transition systems. [PP]
  7. Alternatives to plastic mulch for organic vegetable production.
  8. Post-plant management of nematodes in apple orchards in Washington. [PP]
  9. Field efficacy trials of Metarhizium anisopliae alone and in combination with entomopathogenic nematodes against the larval stage of the Carrot Rust Fly (Psila rosae). [PP]
  10. Understory management in organic tree fruits. [PP]
  11. Nitrogen supply and partitioning in managed understories of organic apples. [PP]
  12. Economic trends in organic production and marketing. [PP]
  13. Organic apple price in response to crop size supplied to the market. [PP]