KẾT QUẢ NGHIÊN CỨU KỸ THUẬT PHÒNG TRỪ TỔNG HỢP MỘT SỐ LOÀI CỎ DẠI KHÓ TRỪ TRÊN CÂY LẠC Ở HÀ NỘI VÀ BẮC GIANG

Weeds in upland crops are very diversified in species and density. They develop very fast, have a competitive power and are harmful for upland crops. Meanwhile, farmers have some basic effective management techniques against many popular weeds such as: Echinochloa colonum L, Chenopodium album L, Alternanthera sessilis L,.. but those techniques have low effect against weeds which reproduce by underground trunk (such as:Cyperus rotundus Linn, Panicum repens Linn) or develop too fast (Bidens pilosa L) or sensitive to herbicide chemical (Cyanotis axillaris L. Roem). Invesigating weeds in cropping peanut, soybean soil at Ha Noi as well as Bac Giang find out that there isn’t a big fluctuation among 51 weed species (investigated at 2 regions) of 22 families, among them, the Poaceae family is most popular with 15 specices. With toughly destroyed weeds in upland crops, besides some management methods such as: clean seed, clean field, using herbicides with considering at after-seeding period, method that using Glyphosate 3.5l/ha before seeding and combine with weeding some times at 30 days after seeding have good effect with toughly destroyed weeds in upland crops.