Abstract
Volcanic ash soil infested with M. incognita was treated with "Vydate" (1% oxamyl) at doses of 300 or 400kg/ha, or with "Mocap"(5% ethoprophos)at 200 or 300kg/ha and potted for the cultivation of tomato plants at 17, 22, 27. and 32°C for 40 days in Experiment 1, and for 27 days in Experiment 2.
"Vydate", applied at the concentration of 200-400 kg/ha, significantly reduced the number of nematodes and of root-galls in the tomato root-systems at lower temperatures (17 and 22°C). However the numbers increased considerably at higher temperatures (27 and 321°C). This chemical induced the suppression of root penetration by the nematodes up to 29 days with little nematicidal action at a dosage level of 400 kg/ha regardless of the temperature. "Mocap", applied at 200 kg/ha, markedly reduced the numbers of the nematodes and of root-galls in tomato roots due to both a nematicidal effect on the nematodes in soil and inhibition of their penetration. However the numbers gradually increased as the temperature rose from 17 to 32°C.
