Division of Nematology, Indian Agricultural Research Institute, New Delhi-110012, India.
1 Part of Ph. D. Thesis submitted by the senior author to P. G. School, IARI, New Delhi.
Pathogenicity tests with Heterodera zeae on two cultivars of maize, namely, composite Shakti and hybrid Histarch, revealed that an initial inoculum of 100 larvae and above per kg of soil for Pusa (Bihar) population and 1000 larvae for Udaipur population significantly reduced various plant growth characters in comparison to uninoculated check plants. These inoculum levels are being considered as the minimum damaging threshold. The host infestation and nematode multiplication were density dependent with maximum cyst production and nematode reproduction occurring at 1000 inoculum level.
Heterodera zeae, pathogenicity, damaging threshold, Zea mays
