Effect of combining soil solarization with certain nematicides on target and nontarget organisms and plant growth

Field experiments compared pesticidal and plant growth effects of soil solarization, alone and in combination, with overall applications of several nematicides. Nematodes, including Meloidogyne incognita J2, that were targeted for control were significantly reduced (P < 0.05) by solarization, 1,3-dichloropropene (44 and 132 liter/ha), ethoprop (13.5 kg/ha), metham sodium (64 liter/ha), formaldehyde (111 liter/ha), and by solarization-nematicide combinations. Control of Pythium ultimum also was obtained by all of the treatments; however, none of the chemicals or combinations of chemicals and solarization controlled nematodes or P. ultimum significantly better than solarization alone. Numbers of cotton (Gossypium hirsutum cv. Acala SJ-2) seed-applied Trichoderma viride and Bacillus subtilis which colonized the plant rhizosphere were not affected. Yield of carrot and survival of cotton seedlings was sometimes increased by solarization and (or) chemical treatments. No significant phytotoxicity from soil treatments was found on cotton or carrot.