Association of White-tip Nematode with Chaffiness of Rice in Haryana

摘要

Rice is the staple food for 40 million in India. Chaffiness and discolouration in rice grain are being observed in several parts of the country. Whole panicles become chaffy due to damage caused by yellow stem borer (Muralidharan and Pasalu, 2006). Some times stem borer larvae may feed within the stem without severing the growing plant parts at the base resulting in reduced plant vigor, fewer tillers and many unfilled grains (Pathak, 1968 and 1975). Ill emergence, partial filling and chaffiness of the grains were found to be associated with the white-tip nematode infestation (Prasad et al., 1987). Krishnan and Rao (2005) observed that proportion of seed discolouration and setting was influenced more by environmental factors than by genotypic effects. In the present study on organically grown rice field exhibited chaffiness in the panicles which could not be directly correlated to yellow stem borer (YSB), Scirpophaga incertulus damage. Earlier studies have reported association of chaffiness in panicles with damage by white-tip nematode (Aphelenchoides besseyi) (Rao et al., 2000) in addition to that of YSB. However, this nematode has not been reported from the area of the present study. Hence, effects were made to diagnose the causes to this malady.