Weed communities and distribution characteristics in the paddy fields of main rice growing regions of Hubei Province

Comprehensive weed infestation indices of existing weed populations from 25 sampling sites in three main rice growing regions, Jianghan Plain, Huanggang region, and Xiangfan-Suizhou region, of Hubei Province were determined by a seven-point scale through weed dominance visualization. 43 weed species of 23 families were collected. The comprehensive infestation index ranking of the dominant weed species is Echinochloa crusgalli, Paspalum paspaloides, Alternanthera philoxeroides, Monochoria vaginalis, Leptochloa chinensis, Ludwigia prostrate, Eclipta prostrate and Lemna minor. Of the weed species, the dominant weeds in Xiangfan- Suizhou, Jianghan and Huanggang regions are Echinochloa crusgalli, Alternanthera philoxeroides; Echinochloa crusgalli, Paspalum paspaloides; Echinochloa crusgalli, Monochoria vaginalis respectively. There is a strong similarity between weed community in the paddy fields of Jianghan Plain and Huanggang region, with a S?renson index of 0.774 1. Weed communities in the paddy fields in the two regions are less similar to that in Xiangfan-Suizhou region. Overall, weed community richness in the paddy fields of Hubei Province is low. This is probably due to long-term utilization of herbicides in the province.