First, the main weed species in Jiangsu Province, rapeseed is mainly winter-sowing rapeseed, spring rapeseed rarely, the occurrence of weeds in winter sown rapeseed fields and wheat fields are basically the same, the former has two types of dryland oak and rice plate oysters. The main weeds in the rape and rapeseed are: Poria pilosula, Mairenzhu, Veronica, Oyster, S. sophia, Amaranth, S. bracteatum, L. lucidum, Poa pratensis, Wild Oatmeal, Bacteria, Wheatgrass, Thorn Children's dishes, small convolvulus, and so on, wild oats in some areas are seriously endangered. The main weeds of rice indica oilseeds are mainly amaranth, Japanese amaranth, hard grass, and bluegrass. Others are grassy, ​​bristle, burdock, ragweed, big broccoli, and glutinous rice bran. The leeks, mother-in-law, and rice-grass are the most serious hazards to see if Aunt Maiting occurs. In some areas, hard-grass and early-maturing pods are also more harmful. In spring rapeseed fields, the main weeds are wild oats, alfalfa, flat storks, chicory, giant burdock, curly stalks, swine crickets, ion grass, citrons, sage flowers, alfalfa, marmot, and barnyardgrass. When asked about Jing, etc., wild oats are the most dangerous. There are more weeds in rice field than in dry land. Second, the occurrence of rapeseed cultivation methods are two kinds of live rapeseed and rapeseed transplanting, in the way of farming, there are two kinds of planting, planting, turning and sowing. There are also obvious differences in the occurrence of field weeds. During the seedling stage of transplanting rapeseed, the main focus is on amatricids, head grasses, mother-in-law, and herbivores. The peaks of hair growth are 7-10 days after sowing, and the co-bearing period with rape is shorter, and rape seedlings are dense and grow fast. The grass is lighter. The characteristics of weed occurrence in rapeseed field planted and planted in winter sowing are similar to that of wheat field planted in the same period. The peak of hairiness occurred 10-30 days after sowing, and the amount of weeds produced during this period was the main weed population that constituted the weeds in rape fields. The weeds in dry land were mainly dominated by broadleaf weeds and had a relatively small amount of weeds; whereas the rice weeds with weeds originated mainly with grass weeds, with a greater amount of grass weeds. In the rapeseed field planted in winter sowing, the soil surface layer outside the sowing hole (line) was not destroyed, and the soil surface weed seeds had germinated before sowing to form the early weed community in the field; Line) Topsoil was destroyed, and the germination peaks of weeds sprouted in sowing holes (rows) and overturned soil layers occurred 10 to 30 days after sowing. Since the rapeseed field grows vigorously in the spring and grows fast, only a few kinds of weeds, such as big broccoli, swine fever, and wild oats, can have a greater impact on rapeseed production, and many of them are naturally extinct due to the infestation of rapeseed plants. With the exception of a few delayed late planting plots with poor rape growth, the weeds that sprouted in spring fields had little effect on rapeseed and could not be dealt with. 3. Control and Prevention of Rape Weeds in Rape Fields Based on the application of various agricultural measures, based on the cultivation methods of rapeseeds and the characteristics of the main communities of weeds in rapeseed fields, appropriate varieties and formulas of herbicides should be selected, focusing on the development in autumn and winter. Control. 1. The seedlings or seedlings after field sowing are sown before weeding because weeds are harmed for a short period of time, and the advantage of seedling populations is easy to form, just to ensure that the seedlings grow safely in early stages. Therefore, 60% butachlor EC may be used for 75-120 ml, 50% for Caudadan EC for 200-250 ml or 48% for Alachlor EC for 200-250 ml, and 40-45 kg of water for manual spraying. Before the control. 2. Chemical cropping before planting For Brassica napus, the weeds that have germinated in the field after harvesting of the former loquat crop before the rapeseed planting should be controlled by the exterminating herbicide or regenerated by the former loquat. Can choose to use 41% glyphosate water 100 ~ 150 ml or 20% gram trace (paraquat) EC 200 ~ 250 ml, or similar agents on the water 30 kg manual spray control. 3. Soil treatment during the planting period For rape fields mainly consisting of Japanese amaranth and grass weeds, 48% trifluralin EC 100-150 ml can be used for 3 to 5 days prior to rapeseed sowing and mixing. Or use 65% of spermatoline 45-60 ml, 48% clomazone EC 50 ml or 50% acetochlor EC 75-100 ml before broadcast seedling before sowing, transplanting rapeseed or After the planting, apply pesticides the next day. For rapeseed fields mixed with grassy weeds, broad-leaved weeds, leeks, and rolled-eared weeds, a mixture of either dole or Querchuang, or pretilachlor and Guangmailing may be used before rapeseed sowing Or apply pesticides before planting. 4. Post-emergence stem and leaf spray For rape fields dominated by grass weeds, it is possible to use 10.8% of efficient straw-covered 20 to 30 ml, 10% of quizalofop EC, 35 to 50 ml, and 6.9% of Granville. Frazoxacin) 40 to 50 ml of emulsifiable concentrate, etc., was controlled before the weed 4 leaf stage. For the plots mainly consisting of small broccoli, sophora sinensis, rice leeks, mash, wild geranium, etc., 50% of high gram (grass removing agent) suspension can be used for 30-40 ml or 33% of mu. Weeding Tong (Pendimethalin) 50 ml emulsion, spray 40 kg of water, in autumn and winter to control. For hard-grass and bluegrass-based plots, use 24% clomazone EC for 20-30 mL to control the weeds at the 3 to 4 leaf stage.