苏北垦区豆田杂草生长为害习性

苏北垦区豆田杂草分属15科,36属,41种,恶性杂草有稗,苍耳等9种。在大豆整个生育期间通常出现1～2个萌发高峰,主要集中在6月中旬～7月下旬。杂草种子于8～10月成熟。种子在土壤中的埋深及出苗期,直接影响杂草的出苗和繁殖。杂草与大豆的相互竞争,以在大豆播种一个月后最为剧烈。0～2cm和6～25cm耕层中贮葳的杂草种子最多。

GROWTH AMD INFESTING HABIT OF WEEDS IN SOYBEAN FIELD

Soybean field weeds in the North of Jiangsu province have been divided into15 families, 36 genera and 41 specieses. Weeds are Barnyard cause worse damage grass , Crabgrass,Cockleur and Copperleaf etc. Through the whole development stages of soybean, there are 1-2 peaks of weed seedling emergence concentrating in middle June to late of July. The weed seeds ripe from Augast to October. Seedling emergece amd reproductive rate of weeds would be effected by the burial depth of weed seed in soil, as a rule, The highest rate of seedling emergence and seed reprroduction is that when seeds are buried 0. 5 to 4cm below soil horizon. Weeds compel strongly with soybeans one month after soybean was sown. Most seeds are buried in the soil layer 0 to 2 and to 25 cm below the horizontal surfaee. Compring with other crops, Chemical control for soybean weed can achieve the more effectiveness of econmice and society.Application of pre-germination and post-emergence with herbicides are needes for weeds control in soybean. Combining herbicied application of per - germination and post - emergence herbicide for monocotyledonous weed and broad - leaved weed, using many kind of herbicides, depending on weed species to deide herbicide application and careful attention should be given to the dynamics of weed population, the more effectiveness can be obtained.