山东省菏泽市棉田杂草发生规律研究

棉田杂草因其与棉花争水、争肥、争光照，甚至助长病虫害的发生，严重影响棉花的优质、高效生产。为明确山东省菏泽市棉田杂草发生、危害情况，于2013年对菏泽地区棉田杂草种类、出土规律及其群落自然消长动态进行了调查。结果表明：山东省菏泽市棉田共发现杂草24种，分属于14个科，其中禾本科、菊科杂草的发生种类较多；牛筋草、反枝苋、马唐的发生数量最为显著，其次为马齿苋、狗尾草、铁苋菜、香附子、藜，这几种杂草在田间发生数量、密度均较大，是菏泽棉田的主要危害杂草；田间共有3个杂草出土高峰，分别集中在5月下旬、7月初和8月中旬，第一个出土高峰中杂草的出土量较大；自然混生杂草群落内的总杂草数量在6月底达到峰值且在棉花整个生长季节内呈单峰变化。

Study on Occurrence Regularity of Weeds in Cotton Fields in Heze, Shandong Province

Weeds, which compete with cotton in the water, fertilizer, sunlight and even conducive to insects and diseases, have serious influences on the production and quality of cotton. To clarify the occurrence and damage of weeds in cotton fields of Heze, Shandong Province，we conducted a thorough investigation on the species of weeds, the pattern of emergence and the succession of the weed community in 2013. A total of 24 weed species, which belong to 14 families, existed in the cotton fields of Heze, Shandong Province. Of the 14 families, Poaceae and Compositae ranked the top two. Eleusine indica, Amaranthus and Retroflexus were the most common weeds, followed by Eleusine indica, Amaranthus, Retroflexus, Digitaria sanguinalis, Portulaca oleracea, Setaria viridis, Acalypha australis, Cyperus rotundus and Chenopodium album, which had a high frequency and density in the cotton fields. There were three peak periods for weeds’emergence, concentrated in late May, early July and middle August respectively, and most of the weeds emerged in the first period. The total amount of the weeds in the natural community reached the peak at the end of June and appeared unimodal change in the whole growing season of cotton.