安徽省沿江棉区两种栽培方式下棉田杂草发生与危害研究

初步研究了安徽省沿江棉区直播棉田和移栽棉田杂草发生和危害。运用杂草群落的重要值(MDK)和相对多度(RA),结合K类中心聚类法分析两种模式棉田杂草发生和危害程度。在直播棉田和移栽棉田中,杂草发生种类和杂草演替规律差异不大。一般是以禾本科杂草牛筋草、马唐为重要杂草,由铁苋菜、狗尾草、马齿苋、通泉草、反枝苋和异型莎草等主要杂草组成的杂草群落;直播棉田杂草在棉花蕾期发生密度较大,对棉花的危害程度也较大。两种栽培方式下,不除草棉田的棉花前期株高、叶片数、果枝数和果节数显著低于常规除草棉田;后期的株高、单株铃数、单铃重显著低于常规除草棉田,皮棉产量减少极显著。

Analysis of weed infestation and its harmfulness to cotton in two cultivation patterns of cotton-fields along Changjiang River, Anhui Province

Using important value(MDK) and relative abundance (RA) of weed community as indices , together with K-means clustering, the weed infestation and its harmfulness to cotton was stated in direct-seedling cotton fields and transplanting-seedling cotton fields, respectively. Within two different cultivation patterns, there were little difference in weed species and weed succession. Generally, two gramineae weeds (goose-grass herb and crabgrass )were the important weeds; copperleaf , green bristlegrass, purslane, mazua miquelii, redroot pigweed, and smallflower umbrella sedge were the main weeds, which constituted of weed community in cotton fields along Changjiang River in Anhui Province. However, the densities of the weeds in cotton fields with direct-seedling were more high, and their harmfulness to cotton were more serious. Within the two different cultivation patterns, cotton height, leaves, fruit branches and fruit nodes were remarkably lower in no-weeding fields than in weeding fields; cotton height, bolls per plant and single boll weight were evidently lower in no-weeding fields than in weeding fields. The lint yields per hectare declined significantly in no weeding fields.