DISTRIBUTION PATTERN OF WEEDY RICE IN WET SEASON RICE CROP IN THE RED AND LATERITIC BELT OF WEST BENGAL

Abstract

A survey on different species of weedy rice in rice crop fields was carried out in the red and lateritic belt of West Bengal, India during 2010 in the farmers’ fields of Purulia, Bankura, Birbhum and parts of Burdwan districts. The Survey of weedy rice was carried out in 81, 77, 75 and 21 villages from 17, 18, 18 and 7 blocks out of 19, 22, 19 and 7 blocks present in Purulia, Bankura, Birbhum and parts of Burdwan district respectively. Four weedy rice species viz. Oryza rufipogon Griff., O. barthii A. Chev., O. minuta Presl. Ex. Presl., O. nivara were identified during the survey. It was observed that population of weedy rice was higher in Birbhum district as compared to other districts under the survey. The frequency percentage and absolute density were 54.9 and 0.8, 44.04 and 0.69, 40.4 and 0.57and 35.7 and 0.43 in Birbhum, Parts of Burdwan, Bankura and Purulia district respectively. Out of 81, 77, 75 and 21 villages under survey the frequency percentage was more than 50 percent in 26, 31, 42 and 11 villages. The damage is likely to increase in subsequent years, if not managed effectively, challenging the rice production system in the districts under survey