Analysing The Distribution Characteristics Of Resistant Weeds Which Were Growed In Paddy Fields Of Jilin Province

In order to explore the resistant weeds and its distribution characteristics in jilin province and provide theoretical basis and methods for the effective control of resistant weeds, weeds which are insensitivity to pesticide effect and wild weeds were made respectively as resistant and sensitive materials, by using pot culture and field investigation method, the existence of resistant weeds and the degree of resistance were identified, the distribution characteristics of resistant weeds was investigated and the extent of the disaster of resistant weeds in paddy fields was analysed.Sagittaria sagittifolia and Monochoria korsakowii are common weeds which are not one of malignant weeds in paddy fields. Because of successive use for several years and over-use of those sulfonylurea herbicides, sulfonylurea-resistant herbicides such as Sagittaria and Monochoria korsakowii occurred on a large scale and they had been the dominant weed species in paddy fields. The result of investigating the main rice planting area between 2010 and 2013 in jilin province indicates that Echinochloa crusgalli (L.) Beauv. which is resistant to Cyhalofop-butyl, hydrogen fluoride grass ester, penoxsulam and bensulfuron-methyl are found in paddy rice; Invasive Leersia Orygoides. L. (SW). which is resistant to Quinclorac, cyhalofop-butyl and penoxsulam are found in paddy rice; Weedy rice Linnaeus which is resistant to herbicide used commonly are also found in paddy rice. Among them, the resistant Echinochloa crusgalli (L.) Beauv.are distributed in the main rice planting area of jilin province, the resistant Leersia Orygoides. L. (SW) are distributed in the east rice planting area, the Weedy rice Linnaeus are distributed in the east and parts of the Midwest areas; The resistant Leersia Orygoides. L. (SW) spread rapidly and large density and serious weed problems happened, consequently it has become one of malignant weeds in our province. According to the characteristics of weeds resistance in different rice areas, it is suggested that agricultural measures and the comprehensive prevention technology of chemical prevention should be taken. The distribution and occurrence characteristics of Sagittaria sagittifolia and Monochoria korsakowii were investigated and analysised, resistance characteristics were identified, so that effective control technology were discussed. The results of investigation and analysis show that the harmful of weeds is serious in paddy rice fields in Yanbian and Tonghua, relatively light in paddy rice fields in Songyuan、 Changchun and Jilin. Under the standardized measurement, the results of surveying sulfonylurea herbicide resistant ecotype of Sagittaria sagittifolia show that the probability of resistant ecotype in Yanbian paddy fields was 63.6%, the probability of resistant ecotype in Tonghua paddy fields was 0, the probability of resistant ecotype in Jilin paddy fields was 67%, the probability of resistant ecotype in Songyuan paddy fields was 100%; Under the standardized measurement, the results of surveying sulfonylurea herbicide resistant ecotype of Monochoria korsakowii show that the probability of resistant ecotype in Yanbian paddy fields was 87.5%, the probability of resistant ecotype in Tonghua paddy fields was 67%, the probability of resistant ecotype in Jilin paddy fields was 100%. The resistance of Sagittaria sagittifolia and Monochoria Korsakowii to bensulfuron-methyl is different in paddy rice fields in Jilin province. The ED50 of Sagittaria trifolia in Jinlin baiqi and sijiazi to Bensulfuron-methyl is 18.5 and 36.9. The ED50 of Monochoria Korsakowii in Yanbian helong to Bensulfuron-methyl is 9.7; But the ED50 of Sagittaria trifolia in Jinlin baiqi to Penoxsulam is 45.6. It indicated that Sagittaria trifolia is resistant to Bensulfuron and Penoxsulam, and it may have cross resistance.The results which studies the effect of different herbicides on resistant weeds mentioned above show that herbicides which has good prevention effects on sulfonylurea-resistant herbicides such as Sagittaria, Monochoria korsakowii are prometryn, bentazon,MCPA sodium and so on;Amide herbicides such as pretilachlor should be used to prevent the Echinochloa phyllopogon(stapf)Koss of quinclorac-resistant herbicides in the early stage of its growth or penoxsulam, cyhalofop-butyl and ordam should be used in the middle of its growth.Through analysing the disaster early warning system of resistant weeds in paddy fields in Jilin province, the evaluation and index of disaster early warning of resistant weeds were established, the results show that comprehensive evaluation and index of disaster was high in longjing jilin province, it could be up to 0.579, the estimated grade was the important protected area, comprehensive evaluation and index of resistant weeds in rice fields of Yanji,Helong,Tumen and Hunchun were respectively 0.435,0.324,0.335,0.275.