Project Number: 0500-00044-021-01
Project Type: Specific Cooperative Agreement

Start Date: Sep 25, 2007
End Date: Mar 31, 2009

Objective:
1) Evaluate reduced rates of alternative fumigants applied by drip fumigation under VIF and SIF in combination with metam sodium (sequential application). 2) Determine relative fumigant retention under tarps. 4) Evaluate and demonstrate promising non-fumigant alternatives for strawberry. 5) Demonstrate to growers the performance of key alternative fumigants so that they can make informed decisions during the transition to alternative fumigants.

Approach:
Objectives 1 and 2 will be achieved by testing selected pre-plant fumigation treatments in two field projects in the 2008-09 season. One of the trials will be located in a commercial field in Oxnard and another in a commercial field near Watsonville. Each trial will include 32 factorial treatments in a split-split plot design. Main plots will be allocated to fumigants, and splits of the main plots will be allocated to metam sodium and film treatments. For each trial, data collection will include fumigant retention under tarps; survival of weed seeds, Verticillium dahliae, Pythium, and Phytophthora species in bags of soil buried in the control and fumigant-treated plots, and in-season data such as weed densities and biomass, hand weeding time, and marketable and total strawberry yields. Objective 3 will be achieved by testing eight non-fumigant treatments as well as a non-treated control and the commercial standard of MB/Pic 67:33 at 350 lbs/acre at the Monterey Bay Academy near Watsonville, CA or the Spence Farm near Salinas, CA (Table 2). Two or three experiments will be conducted in 2008-09. In each experiment, each treatment will be applied to four replicate plots in a randomized complete block design. Each replicate plot will be a plant bed that is 20-ft-long by 52 to 68 inch wide. For the steam non-fumigant treatment, steel steam distribution lines with emitters at 10-inch spacing will be installed in the bed to inject steam at a depth of 6-8 inches, with the objective of effectively heating the top 12 inches of soil. The steel lines will be spaced 12-inch apart, with 10-inch spacing between steam emitters. Objective 4 will be achieved by conducting grower field tours, presentations at grower meetings and conferences held by Farm Advisors, production of extension fact sheets, and publications in trade magazines in order to reach a wider audience. Data will be collected to assess the economic viability of the treatments evaluated in this project. The project manager and economist will work with growers to monitor both the costs associated with crop production under the different fumigation treatments and the returns associated with crop sales during the production cycle. Data will be collected for future economic cost/benefit analysis to determine the economic viability of specific alternative fumigant treatments. Budgeting for an economist will start in the second year of the project.