Incidence of white tip nematode ( Aphelenchoides besseyi ) in rice in West Bengal

Surveys were conducted to document infestation of rice white tip nematode (Aphelenchoides besseyi) during the boro and kharif seasons in West Bengal. Results indicated that infection of A. besseyi in rice occurs in both the rice growing seasons. Among the districts surveyed, East (229-2054/100grains) and West Midnapore (69-2277/100grains) and South 24-Paraganas (249-1543/100 grains) were severely affected; the samples from these three districts showed A. besseyi infection of 37.57%, 55.17%, and 28.14%, respectively. Samples procured from Bankura also showed 30% infection of A. besseyi. The sample with low population (per 100 grains) recorded in Hooghly (81-111; 18%), Malda (71-78; 10%), Nadia (77-131; 6%), North 24-Paraganas (76-97; 18%), Purulia (80-101; 15%) and South Dinajpur (59-80; 45%) districts. However, 45% infection was recorded from samples collected from South Dinajpur district. Infestations ranged between 6 to 18% in other districts of West Bengal. No infestation was recorded from Cooch Behar district. The survey results confirmed that A. besseyi is one of the most important pests of rice in West Bengal in both boro and kharif seasons. Further, the areas infested with this nematode species are potential sources of nematode dissemination to other parts of India through production of nematode infected seed.