The relation between wheat yield and early damage of roots by cereal cyst nematode

Abstract

A survey of 14 farmers' fields in the Northern Adelaide Plains in 1978 showed that cereal cyst nematode (Heterodera avenae Woll.) was the major factor limiting wheat yields, with a relation of r = -0.86 (P < 0.001) between damage to wheat roots at the seedling stage and grain yield. None of the 12 physical and chemical properties of the soils measured was related to cereal cyst nematode damage or grain yield. Samples taken from experimental plots with similar soil and climate showed a build up of H. avenae after four successive wheat crops and highly significant negative correlations between the damage to seminal roots by H. avenae, dry weight at flowering, and grain yield. A highly significant positive correlation of 0.84 existed between the damage to the seminal roots and the number of females (white cysts) on the roots at flowering.