Study On The Composition Of Corn Weed Community And The Technology Of Chemical Herbicide Reduction And Synergy In Xinjiang

The composition of weed community in corn field in Xinjiang desert oasis ecological area is unclear,and the problem of unreasonable use of chemical herbicides in corn planting,and the lack of safe and efficient herbicide scientific application and related technologies for reducing and increasing efficiency This paper systematically investigates the structure of weed community in the main maize producing areas of Xinjiang,and preliminarily clarifies the composition of weed communities in the corn field under the desert oasis habitat in Xinjiang and the differences in weed community structure in different areas.On this basis,Through the screening of safe and efficient herbicide types and application rates,and the synergistic use of synergist technology,a set of scientific application of corn herbicides in accordance with the actual production of Xinjiang and its technology of reduction and synergy were established,which is the corn industry in our region.Green,safe and efficient development provide corresponding technical support.The main findings are as follows:1.Analysis of field weed composition and community structure characteristics in main maize producing areas of Xinjiang showed that There are 38 species of weeds in Xinjiang corn producing area,belonging to 17 families and 34 genera,including 3 important weeds,13 main weeds and 22 minor weeds.Echinochloa crusgalli(L.)Beauv.),Setaria viridis L.Beauv.,Chenopodium glaucum L.,Hibiscus trionum L.and Abutilon theophrasti Medicus,and aphid Amaranthus lividus L.is the dominant weed in the area.The analysis of important values and community structure showed that there were differences in important weed species and community structure in different regions.The weed species in spring sowing corn fields were the most abundant in Kashgar,Margalef index(3.6961),Shannon Wiener(2.4632)and Pielou index(0.7560).The highest,while the Margalef index(1.4433)and Shannon Wiener(1.6482)were the lowest in the region,but both were important weeds in the region and the Margalef index in the Urumqi region.(3.1169),Shannon Wiener(2.2006)and Pielou index(0.7346),the important weeds are mainly castor and wild watermelon seedlings;the Imp area weeds have the highest Simpson index(0.2778),indicating its dominant weed damage.The period is the most concentrated,and the gray and green crickets are important weeds in the area.The analysis of the niche breadth further validates the advantages of important weeds in each of the above regions.The analysis of niche overlap values indicated that the sedge,sedge,yarrow,ramie and sedge flowers in the Urumqi region,the stalk and the longan in the spring sowing corn fields in the Kashgar region,and the ramie and gray-green in the re-broadcast corn fields in the Kashgar region.The niche overlap values of major weeds such as alfalfa and important weeds in the region are higher.2.Screening of safe and efficient herbicide types and application rates showed that the types and application rates of herbicides that can safely and efficiently control corn weeds in production are closed:38%atrazine SC 1500 mL/hm~2,38.5%mesotrione·dexamethasone·atrazine CS 6000 mL/hm~2,stem and leaf treatment:40g/L nicosulfuron OD 1200 mL/hm~2,28%mesotrione·nicosulfuron·atrazine OD 2700ml/hm~2,24%mesotrione·nicosulfuron·atrazine OD 2700 mL/hm~2 and 50%isooctyl chloropyroxyacetate·mesotrione·nicosulfuron WG 450 g/hm~2.The 30%oxacillin SC 225 mL/hm~2 had the worst control effect,and the total grass plant control effect and total grass fresh weight control effect at 30d and 45d were only 60.00%,56.07%and 21.88%,41.73%.3.Herbicide reduction and synergistic technology research:based on the above-mentioned herbicide types and application screening research,the best application rate of two representative herbicides(40%mesotrione·Oxalamine·atrazine CS 400ml/mu,26.7%thiazsulfuron-methyl·isoxazolone SC 30ml/mu)was used as a baseline for drug reduction,and three additives(63%Jijian synergist,HuiFeng synergist and Heilongjiang University 2#synergist)were systematically evaluated were used in combination with chemical herbicides to achieve different efficacy(0%,-15%,-30%)of plant control and fresh weight control.The results showed that The adjuvant can reduce the herbicide by 30%at the current level.However,there are some differences in the synergistic effects between different synergists,and the pesticides of different dosage forms have certain effects on the synergistic effect.In actual production,it should be reasonably matched according to the types of pesticides and synergists.