EFFECT OF SOLARIZATION AND COWPEA COVER CROP ON PLANT-PARASITIC NEMATODES, PEPPER YIELDS, AND WEEDS

Abstract

Two field experiments with bell pepper (Capsicum annuum) "Wizard X3R" were established (May 2003, 2004) in Marion Co., Florida, U.S.A. The objective was to compare yields, nematode populations, and weeds as impacted by six soil management treatments: cowpea (Vigna unguiculata) summer cover crop, solarization on a raised bed, solarization on a flat surface, cowpea cover crop followed by raised bed solarization, methyl bromide fumigation, and untreated control. Soil samples were obtained after all treatments had been applied, just prior to planting, and at the end of the season to determine the effects of treatments on nematode population densities. In 2003 prior to planting, ring nematodes (Mesocriconema sp.) were most prevalent in the control treatment and lowest in the cowpea cover crop combined with raised bed solarization, and the methyl bromide fumigation treatments. At the end of both seasons the combination of cowpea cover crop with bedded solarization was as effective as methyl bromide fumigation for suppressing root-knot nematodes (Meloidogyne spp.). In 2004, raised-bed solarization was also as effective as methyl bromide for suppressing root-knot nematodes. All solarization treatments were effective in suppressing weeds compared to the untreated control, and were more effective than methyl bromide in 2003 when no glyphosate was applied during the summer. Solarization treatments were equivalent to glyphosate-treated methyl bromide and control plots in 2004. Pepper yields of U.S. Fancy grade and total fruit weight in 2003 were higher in raised-bed solarization than methyl bromide fumigated plots. Cowpea in combination with raisedbed solarization resulted in higher total fruit weight relative to methyl bromide fumigation. Two hurricanes followed by a Pythium sp. epidemic confounded yield differences in 2004. However, flat solarization resulted in greater total fruit number and weight of U.S. #1 grade peppers than methyl bromide fumigation. Solarization and solarization combined with a cowpea cover crop can be useful alternatives for nematode and weed suppression, and improved yield of pepper.