In Vitro toxicity of DBCP to some phytophagous nematodes and hatchibility of Heterodera cajani

Toxicological tests with different concentrations of DBCP and exposure of Pratylenchus zeae, Tylenchorhynchus vulgaris and Hemicriconemoides cocophiilus revealed that the percentage mortality was directly proportional to both the increased concentration and exposure period. There was almost complete kill of all three nematode species when exposed to 160 ppm or more for 24 hours. Using CTP as parameter, T. vulgaris was found to be more susceptible to DBCP exposure as compared to P. zeae and H. cocophiilus.. Further, P. zeae was found to be more susceptible at 20° than at 10° or 30°C. Similarly, larval emergence from cysts of Heterodera cajani was proportionately affected with an increase of DBCP concentration and exposure period. Larval emergence was reduced to 9.5, 4.8 and 0 8 per cent in 640 ppm for 2, 4 and 8 days respectively as against 41.0 per cent emergence in check treatment.