论文部分内容阅读
１９９６～１９９７年在浙江嘉兴调查了湿润直播稻田杂草出苗动态和发生规律，并比较了直播与移栽，早稻、单季晚稻与连作晚稻直播，翻耕与免耕直播间杂草发生差异。湿润直播稻田杂草以稗草、千金子、异型莎草、节节菜、陌上菜为主，其次有通泉草、丁香蓼、水芹。禾本科、莎草科和阔叶杂草种类数分别占２５．０％、１８．８％和５６．２％，出苗数量分别占１１．２％、１１．６％和７７．２％。单季晚稻直播田稗草、千金子发生重于其他直播田，直播田稗草和千金子数量明显高于移栽田。直播田杂草于播种后３～４ｄ陆续出苗，１～３周达到高峰。连作晚稻直播田播后６～８周出现明显的第二个出苗高峰。以阔叶杂草为绝对优势的翻耕直播田杂草发生重于免耕田。直播田杂草数量自然消长呈现与出苗动态相同的趋势。直播田杂草发生以稗草、千金子、丁香蓼较早，节节菜、陌上菜、通泉草次之，异型莎草和水芹较迟。稗草、千金子及其他几种主要杂草出苗高峰均呈单峰状态，而节节菜、陌上菜在连作晚稻直播田的出苗则为双峰。
The dynamics and occurrence of weeds emergence in the wet and direct seeding rice fields were investigated from 1996 to 1997 in Jiaxing, Zhejiang Province. The differences of weeds between direct seeding and transplanting, early seeding rice, single seasons late seeding and continuous seeding late seeding, direct seeding and no-tillage direct seeding were compared. Wet weedy direct-seeded rice to barnyard grass, Qianjinzi, Shaped sedge, section dish, street food-based, followed by Tongquan grass, clove Polygonum, cress. The species number of grasses, sedge and broadleaf weeds accounted for 25.0%, 18.8% and 56.2% respectively, and the number of emergences accounted for 11.2%, 11.6% and 77.2% respectively. Single-season late-season direct-seeding Echinochloa crusgalli, Trichosanthes occurs more heavily than other direct-seeding fields, the direct seeding field barnyardgrass and semen number is significantly higher than the transplanting field. Live weeds in field 3 ~ 4d after sowing one after another emergence, 1 to 3 weeks to reach the peak. Even for late rice broadcast sowing 6 to 8 weeks after the apparent emergence of the second peak. Weeds dominated by broadleaf weeds were dominant over tillage and direct seeding fields. The number of live weeds naturally showed the same growth and emergence of the same trends. Livecasting weeds occur with barnyardgrass, Qianjinzi, Polygonum early, section dish, street food, Tongquan grass second, shaped sedge and cress late. Barnyardgrass, Qianjinzi and several other major weeds peaked in single peak state, while the stem dish, street food in late rice in direct seeding field emergence as a double peak.