The Occurrence Of Weed And Screening Of Herbicides In Corn Field With Drip Irrigation Under Mulch Film In Shihezi

Corn is one of the important grain crops in Xinjiang.With the planting area and the total output increased year by year,the corn occupies more and more important position in Xinjiang economy.In recent years,corn yield has been improved through variety improvement and cultivation techniques,but the damage of weeds in corn fields has seriously affected the yield.In this study,weed species in the cotton field,the type,quantity,trends and the occurrence of law were investigated lasted for 3 years.Different species and dose of soil treatment and leaves treatment herbicides were screened,and determined the optimum spraying dosage,and provided theoretical reference for weed controlling in corn field with drip irrigation under mulch film.The main results are as follows:1.There were 74 species of weeds,belonging to 13 families,which of 63% were grassy weeds,37% were broadleaf weeds and sedge.Annual weeds accounted for 86% of weeds,perennial weeds accounted for about 9% of the total weeds.The dominated weed in corn field with drip irrigation under mulch film was grassy weeds such as Echinochloa crusgalli?L.?Beauv.,Setaria viridis?L.?Beauv,Digitaria sanguinalis?L.?.Therefore,herbicide against grassy weeds should be selected mainly in the corn seedling with drip irrigation with mulch film.2.The three herbicides could effectively control the annual weeds and the broadleaf weeds in corn field with drip irrigation under mulch film.The results showed that 50% acetochlor EC had the best control effect,and the other two herbicides were effective against the weeds second.The maize seedlings showed siginificant phototoxicity when spraying 900-1500 g· hm^-2and high-concentration of 2500 g · hm^-2 of acetochlor,and maize plant growth were inhibited.3.The results of field experiment showed that the control effect of 30% of oxadiazonone SC on grassy weed was better than that of broadleaf weed.Control effect of 4% nicosulfuron on monocotyledonous was relatively poor,the control effect was 84-86%.The control effect of mesotrione on broadleaf weeds better than monocotyledonous weeds when stem and leaf treatment applied.In this study,the recommended herbicides and the recommended dosage were as follows: 33% pendimethalin EC(750-900 g·hm^-2;50% acetochlor EC recommended dosage(1200-1500 g hm^-2)and 96% metolachlor EC(750-1200g·hm^-2)could effectively inhibit the growth of weeds in maize field,and the duration of field control was about 45 days.The results showed that the three herbicides could be used as the recommended chemicals in maize field under the recommended dosage.