WSARE 2000 Farmer/Rancher Grants-FW00-010

TITLE: Soil Solarization for Weed and Disease Control in Specialty Crops

Plastic tarps are used to solarize soil

Soil solarization is a method for reducing weeds, diseases, and other pests in the soil. Soil is solarized by laying plastic tarps over the soil for about four weeks during a warm season so that the soil is properly heated. Mike and Sandie Smith, California specialty crop farmers, were recently awarded a Western SARE Farmer/Rancher Research grant, which will enable them to conduct an experiment on the effectiveness of single and multiple bed solarization versus conventional herbicide treatments. They will conduct the experiment on three crops: basil, cilantro, and Swiss chard. Some of their basil fields have Fusarium wilt, so this experiment will also test the effectiveness of soil solarization in combating this disease.

The Smiths will first solarize the soil on three acres for four weeks and will then plant the three crops. An additional control plot will be planted and treated with a conventional treatment. They will harvest the crops between October and December. During the experiment they will collect data about soil temperature, weed control ratings, and Fusarium disease ratings as well as harvest and quality information. The Smiths plan to hold a field day during the growing season for growers and researchers, and they will also have their findings published in a newsletter and broadcast on the radio. Through this experiment, the Smiths hope to find an alternative, sustainable approach to reducing weeds and pests.