关键词: 中晚熟区, 中晚熟区, 玉米品种, 穗部性状

Abstract: In order to make clear the species and emergence trend of weeds in direct seeding early rice fields, to help farmers apply herbicide reasonably.Weed communities in direct seeding early rice fields of Xiangshan were studied by using W type five-point sampling method. The results showed that there were 14 species belonging to 5 families of weeds appearing in rice fields, Leptochloa chinensis, Echinochloa crusgalli were main species of weeds, total numbers of seedling emergence were 73.2%, 13.6%, 13.2% for grasses, sedges and broadleaf weeds, respectively. Grass weeds started to emerge in the fields 3 to 4 days after rice was seeded, E. Crusgalli germinated earlier especially. Sedge weeds and broadleaf weeds started to emerge in the fields 7 to 14 days after rice was seeded. Emergence peaks appear 28 days after rice was seeded, Numbers of weed species were 427, Grasses weeds composed the majority of weeds, accounted for a total of?82.7%. Because of a mass of sedges and broadleaf weeds germinating, the total amount of the weeds appear emergence peaks trend 42 days after rice was seeded, Numbers of weed species were 364.