Soil solarization is a process where growers cover planting beds with clear plastic sheets for several weeks during the summer, trapping heat that destroys weeds, nematodes and fungi. Popular in California and Israel, researchers and growers in Florida are studying the feasibility of implementing the practice, which is seldom used there.
Bob McSorley, a Univ. of Fla. nematology professor is working with Sunshine State Carnations in Hobe Sound, Fla., to determine the practicality and effectiveness of solarization. A study published in the current issue of the Int’l. Journal of Pest Management showed solarization effectively prepared planting beds for snapdragons, in some cases as well as the soil fumigant methyl bromide. Growers and researchers are seeking cost-effective alternatives to soil fumigants. “The big challenge is getting (growers) to adopt it,” said McSorley. “They never thought of doing without soil fumigants.” He recommends interested growers try solarization on a small plot to determine if it gives the results they need.
He said the advantages of solarization are that it’s inexpensive and environmentally friendly, although the plastic sheeting does require disposal. The downside is solarization requires intense sun exposure, so it can only be used during summer, to prepare beds and fields for fall-grown crops. Also, 3-4 months after solarization is used, pest organisms start to return.
Peter Nissen, co-owner of Sunshine State Carnations, said if this year’s study goes well, his company will use solarization on a larger scale in rotation with soil fumigants.