On the relationship between population densities of Heterodera avenae, growth of wheat and nematode mul tiplication*

Studies conducted on the relationship between population densities of Heterodera avenae, indicated a significant negative correlation between varying levels of nematode and plant growth. Significant decrease in plant growth was recorded at 60, 90 and 130 days. The threshold level was found to be 5 eggs and larvaejg soil. A positive correlation was recorded with number of larvae penetrating root, development of larvae inside the root and number of cysts formed. Cyst contents, however, showed a negative correlation.