湖南省棉田杂草调查

对湖南省棉花主产区棉田杂草的种类、发生规律及化学除草情况进行了调查。结果发现, 湖南省棉田常见杂草包括12科, 28种, 其中禾本科杂草占25.00%, 阔叶杂草占67.86%, 莎草科占7.14%; 一年生杂草占78.57%, 多年生杂草占21.43%。相对多度10%以上的杂草有7种, 其中马唐、牛筋草、千金子、铁苋菜、小飞蓬5种杂草为湖南省棉田杂草的优势种, 相对多度分别为37.79%、33.64%、29.15%、26.23%、23.83%。杂草发生呈现3个高峰期, 分别为5月下旬, 6月中下旬, 7月下旬至8月初, 杂草防除主要采用苗前土壤处理和苗后茎叶处理相结合的化学防除方法。

Weed survey in cotton fields in Hunan Province

Weed species, occurrence regularity and chemical control status were investigated in cotton fields in Hunan Province. The results showed that there were mainly 28 weed species which belong to 12 families, including 25.00% of the Gramineae weeds, 67.86% of broadleaf weeds and 7.14% of Cyperaceae weeds; 78.7% of annual weeds and 21.43% of perennial weeds. Relative abundances of 7 weeds species were over 10%. Digitaria sanguinalis, Eleusine indica, Leptochloa chinensis, Acalypha australis and Conyza canadensis were the dominant weeds, with relative abundances of 37.79%, 33.64%, 29.15%, 26.23% and 23.83%, respectively. The weeds have three occurrence peaks, which were in late May, in mid and late June and in late July to early August, respectively. The weeds in cotton fields were controlled by pre-emergence herbicides with the combination of post-emergence herbicides.