EMERGENCE OF INDIAN POPULATION OF CEREAL CYST NEMATODE, HETERODERA AVENAE

Abstract

Investigations on the emergence of juveniles (J2) from Heterodera avenae cysts during the absence of the host crop in natural conditions, revealed emergence from August onwards but not during May to July. The emergence of J2 gradually increased from August onwards coinciding with the decline in temperature in nature. When low temperature and moisture are available, then the emergence of J2 from the cysts occurred and such emergence of J2 during the off season, in the absence of the host roots, is detrimental and does not contribute to the population build up. The magnitude of suicidal emergence recorded was 31%, which might vary depending on the prevalence of low temperatures during the nights and occurrence of the rains durin August-October.