Distribution and Risk Analysis of Rice-Root Nematode, Hirschmanniella oryzaein India

Rice-root-nematode, Hirschmanniella oryzae is an economically important pest of rice widely distributed in rice growing tracts of India, especially the low land irrigated paddy. Based on intensive surveys conducted in different states/regions of country distribution maps of rice-root nematode, Hirschemanniella oryzae has been developed. The distribution map depicts the most infested as well as nematode free area. A definite trend has been found out to predict the level of this nematode population during any year using surplus or deficit rainfall of different months and this has justified the severity/risk of occurrence of this nematode.