Estimation of Loss in Wheat Yield Due to the Cerealcyst Nematode Heterodera avenae

Abstract

The cereal cyst nematode, Heterodera avenae Wollenweber, 1924, occurs worldwide including India where it causes ‘molya’ disease of wheat and barley. Wheat yield losses due to the nematode were estimated during 1974-76 at a few villages in Mohindergarh district, Haryana, India, by applying dichloropropane-dichloropropene mixture and dibromochloropropane singly or in combination as soil f umigants. In light soil the cereal cyst nematode infestation at 4/5 eggs and larvae/g soil approximated the economic threshold level. However, depending on the initial population density of H. avenae and other field conditions, such as soil type, moisture, soil condition, chemical application method, chemical application time etc., the increase in yield of wheat cv. Kalyan Sona ranged from 8 to 49% at nematode infestation levels of about 6 to 13 eggs and larvae/g soil when treated with these nematicides.