旱直播稻田杂草发生种类多、数量大,易形成草荒,现将旱直播稻田杂草发生特点和防除技术介绍如下。杂草发生特点(1)杂草种类。随着旱直播年限的增加,田间草相越来越复杂。(2)出草特点。田间以稗草的竞争力最强,其次是异型莎草、耳叶水苋、野荸荠;千金子在以上杂草存在时,竞争优势不明显,在没有稗草和莎草存在时,分蘖力很强,生长迅速,危害极大;其他中下层杂草在数量上和生长量上竞争力均表现很弱。 Dry weeds in direct broadcast rice variety, large in number, easy to form a grassland, weeds are now direct broadcast of weeds in rice and control techniques are as follows. Weed occurrence characteristics (1) weed species. With the increasing number of live broadcasts, the grass field in the field is getting more complicated. (2) the drafting characteristics. Barnyardgrass was the most competitive in the field, followed by Shaped Seeds, Amaranthus and Wild Water Chestnuts. When the above weeds were present, the competitive advantage was not obvious. In the absence of barnyardgrass and sedge, tillering power Strong, rapid growth, great harm; other lower middle and lower weeds in quantity and growth on the competitiveness of the performance are weak.