EFFECT OF TEMPERATURE ON JUVENILE EMERGENCE OF SPANISH POPULATIONS OF HETERODERA AVENAE

Abstract

Hatching tests with Spanish populations of Heterodera avenae using cysts in distilled water kept in soil at 15 cm depth, showed juvenile emergence beginning in the autumn at 15-20ºC, without needing a cold stimulus. Maximum emergence coincided with temperatures of 5-10.5ºC and emergence stopped in spring as temperature approached 15ºC. Percentage of emergence was about 90-100% far 8-17% of the individuals, and =60% far 14-28% of them.