Gulf Coast Research and Education Center
14625 C.R. 672, Wimauma, FL  33598
(813) 634-0000  SC514-6890
Fax (813) 634-0001
 Jack Rechcigl, Center Director

Soil Treatments for Disease, Nematode, and Weed Control

Research on chemical alternatives to methyl bromide in response to the impending ban of methyl bromide has been a major program at GCREC for the past seven years and has produced many of the current practices in the industry today.  The industry-wide accepted application procedure for metam sodium was developed here.  The current methyl bromide alternative practice of Telone C-17 C-35 with Tillam herbicide was developed and research continues on this topic.  Additionally, herbicide research has been integrated into the fumigant program to search for package solutions for all of the major soilborne pests of the important vegetable crops of the area.
 
Soil solarization, a process whereby raised beds are covered with clear polyethylene mulch film and are allowed to absorb infrared heat from sunlight for eight weeks to achieve temperatures high enough to kill many soilborne pests, has been studied as an alternative to methyl bromide soil fumigation.  Results have been very erratic, ranging from good to no control of various soilborne pests, including weeds, nematodes and disease organisms; thus, demonstrating that solarization is not an acceptable substitute for methyl bromide for all growers, but might fit certain niche markets, such as organic production of some vegetable crops.
 

Soil solarization, a process whereby raised beds are covered with clear polyethylene mulch film and are allowed to absorb infrared heat from sunlight for eight weeks to achieve temperatures high enough to kill many soilborne pests, has been studied as an alternative to methyl bromide soil fumigation. Results have been very erratic, ranging from good to no control of various soilborne pests, including weeds, nematodes and disease organisms; thus, demonstrating that solarization is not an acceptable substitute for methyl bromide for all growers, but might fit certain niche markets, such as organic production of some vegetable crops.
Testing of herbicides for adaptation to crops and soils in the region dates from 1945. Recommendations for the control of nutsedge were developed in this early period; however, these were generally based on nonselective herbicides or management practices which do not fit current production practices. Improvements in weed control, especially nightshade and nutsedge, have been a major focus of his program and many advances have been made. As a result of extensive field research, highly effective herbicides are now labeled for control of many weeds in most of the important crops of this area. Herbicide research at GCREC has resulted in three emergency registrations, four federal registrations, and two state labels for herbicides in vegetable crops, including strawberry. The residual life of Gramoxone and Roundup on plastic mulch was determined which almost completely eliminates the once common damage from preplant uses of these herbicides on mulched vegetables. The concentration of phenoxy herbicides and Roundup which, in a drift situation, injures tomato, pepper, and cucumber has been determined. Also, soil fumigation greatly affects the longevity and phytotoxicity of phenoxy herbicides in the soil under field conditions, resulting in residues capable of damaging subsequent crops.