Anaerobic soil management practices and solarization for nematode control in Florida

Combinations of flooding, solarization, and amending soil with yard waste compost (YWC) treatments were evaluated for control of root-knot nematodes (Meloidogyne arenaria). Experiments were conducted at Gainesville, Florida for 12-wk periods in the summer of 1996 and 1997 in mesocosms containing an Arredondo fine-sand. Flooding soil induced anaerobic conditions with soil redox potentials near -200 mV in both years. Flooding decreased soil root-knot nematode populations in the order of: continuous less than or equal to intermittent < non-flooded with values (J2/100 cm(3)) of 9, 10, and 36 in 1996, and of 5, 23, and 212 in 1997, respectively. The number of galls found in tomato (Lycopersicon esculentum c.v. Rutgers) roots as a result of both intermittent and continuous flooding in both years were < 1. Endogenous soil populations of ring (Criconemella spp.) and stubby-root (Paratrichodorus spp.) nematodes were also reduced by flooding. Average daily maximum soil temperatures in solarized plots were in the order of: non-flooded with compost > flooded continuously > and non-flooded soil treatments:in 1996 and non-flooded with compost > non-flooded soil > flooded continuously in 1997. In 1996, solarization reduced root-knot nematode numbers 83% in non-flooded plots but did not reduce galling. Combinations of flooding and solarization also reduced root-knot nematode numbers in non-amended plots but galling incidence was not significantly different from the control. In 1997, solarization alone or in combination with other treatments effectively reduced soil root-knot nematode numbers. Root-knot, ring and stubby root nematode populations increased in soil amended with YWC and following rice (Oryza sativa L. cv. Lemont) grown during the flooding period. Combinations of continuous flooding and solarization during the warmest days of the year deserve further study as tools for nematode control under field conditions.