谷莠子是禾本科一年生农田杂草,又名狗尾草。在全国各地均有分布,主要危害谷子、高粱、玉米、棉花、豆类等旱作作物。经研究证明谷莠子和谷子同属狗尾草属,染色体数目相等,可以互相杂交,谷莠子是谷子和狗尾草的杂种,尤其发生于谷田,与谷子相伴,是谷田最难除掉的杂草,成为谷子的伴生杂草。其幼苗和谷子相似,间苗时,容易被当做谷子留下来,使谷子单位面积株 Gramicia is a gramineous annual farm weeds, also known as Setaria. In all parts of the country are distributed, the main hazards millet, sorghum, corn, cotton, beans and other dry crops. Studies have shown that both the diablo and millet belonged to the genus Setaria and the number of chromosomes was equal and could hybridize with each other. The diablo is a hybrid of millet and Setaria viridis, especially in the valley and accompanied by the millet, the weakest weeds in the valley, Associated weeds of millet. Similar to its seedlings and millet, between seedlings, easy to be left as millet, millet unit area strains