|Allen, Leon - Hartwell|
Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/1999
Publication Date: N/A
Interpretive Summary: Methyl bromide is scheduled to be phased out as a soil fumigant by the year 2005. Many vegetable crops in Florida and California depend on methyl bromide preplant soil treatments as a universal disinfestation agent. The search is on for replacement soil treatments and management practices for the control of nematodes, weeds, and soil borne pathogens. Many of Florida's vegetables are grown on seasonally high water table soils that must be drained for vegetable production. ARS- USDA scientists at Gainesville, FL tested the efficacy of soil anaerobiosis induced by soil flooding as a treatment that might be applied to fields during the rainy off-season. Flooding treatments in microplots showed an excellent control of root-knot nematode; however, purple nutsedge, a major weed, was not controlled. Nevertheless, flooding during the summer, off-season might be used as an alternative for the control of root-knot nematode.
Technical Abstract: Combinations of flooding, solarization, and amending soil with yard waste compost (YWC) were evaluated for control of root-knot nematodes. Experiments were conducted by ARS-USDA scientists at Gainesville, FL for 12-wk periods in the summer of 1996 and 1997 in mesocosms containing an Arredondo fine sand. Flooding induced anaerobic soil conditions with redox potentials near -200 mV. Flooding decreased soil root-knot nematode populations in the order of: continuous < intermittent < non-flooded with numbers of juvenile nematodes per ml being 9, 10, and 36 in 1996, and 5, 23, and 212 in 1997, respectively. The number of galls found in bioassay tomato roots was less than one per plant for all flooding treatments. In 1996, solarization reduced root-knot nematode numbers 83 percent in non-flooded plots but did not reduce galling. In 1997, solarization alone or in combination with other treatments reduced soil root-knot nematode numbers. Root-knot nematode populations increased in soil amended with YWC. Combinations of continuous flooding and solarization during the warmest days of the year need further study for nematode control under field conditions.