Study On The Herbicidal Activity And Crop Safety To Wheat Of QYM102

Wheat is one of the most important food crops in China,and widely planted in our country.Currently,herbicides is the most important method for weed control in wheat,but due to overreliance on herbicides application,more and more problems has appeared,such as crop injury,weed resistance et al.Herbicides with new mechanism is needed in wheat crop system.QYM102 is a 4-Hydroxyphenylpyaunate dioxygenase?HPPD?inhibitor.In order to survey the application possibility in wheat fields in China,dose-response experiments were executed in glasshouses and field to assess QYM102 weed control spectrum,herbicidal activity,crop safety to wheats,different factors on the efficacy of QYM102 and the joint effect of QYM102 and fluroxypyr-mepthyl.The research results are summarized as follows:The weed control spectrum,herbicidal activity experiments were executed in glasshouses.The results showed that QYM102 had high herbicidal activity in most of the broadleaf weeds which manifested in wheat field.The fresh weight reduction of Capsella bursa-pastoris?Descurainia sophia?Malachium aquaticum L and Lithospermum arvense were more than 90%at the rate of 20 a.i.g ha^-1.However,the herbicidal activity of QYM102 to grass weeds such as Alopecurus aequalis?Digitaria sanguinalis?Echinochloa crusgalli is low.Fluroxypyr-mepthyl had a wonderful herbicidal activity on Galium aparine,at the rate of 80 a.i.g ha^-1,The fresh weight reduction of Galium aparine is 91.2%,the fresh weight reduction of Capsella bursa-pastoris,Descurainia sophia and Lithospermum arvense were between 60%-79%.The weed control spectrum can be expanded by mixed use of QYM102 and fluroxypyr-mepthyl.The results of wheat safety experiments showed that QYM102 had good safety to wheat.At the rate of 375 a.i.g ha^-1,the fresh weight reduction of wheats were between1.4%-3.3%,the Shannong 6 fresh weight reduction was 3.3%.At the rate of 700 a.i.g ha^-1,the fresh weight reduction of wheats were between 7.6%-13.7%.The selectivity index of QYM102 between three tested wheat varieties Shannong 6?Jimai 20?Weimai 8 and three species of weeds Capsella bursa-pastoris,Malachium aquaticumL,Descurainia sophia were in the range of 32.89-56.31,which were much better than that of tribenuron-methyl.In other words,QYM102 is much safer to wheat than tribenuron-methyl.The results of QYM102 and fluroxypyr-mepthyl mix experiments showed that the joint effect type was additive effect.the selectivity index of QYM102 between three tested wheat varieties Shannong 6,Jimai 20,Weimai 8 and three species of weeds Galium aparine,Capsella bursa-pastoris,Descurainia Sophia were in the range of 8.34-17.56.It showed that the mixture of QYM102 and fluroxypyr-mepthyl was safe to wheat.The field experiment showed that QYM102 had good herbicidal activity for broadleaf weeds in wheat field such as Capsella bursa-pastoris and Descurainia Sophia.The mixture of QYM102 and fluroxypyr-mepthyl can expand the weed control spectrum.The effect of the rate of 30.0 a.i.g ha^-1+90.0 a.i.g ha^-1,30.0 a.i.g ha^-1+120.0 a.i.g ha^-1,40.0 a.i.a.i.g ha^-1+120.0 a.i.g ha^-1,40.0 a.i.g ha^-1+160.0 a.i.g ha^-1were better than single dose.The 40d after herbicide application,the plant control efficiency were 89.4%,91.2%,95.3%,97.4%;the fresh weight control efficiency were 89.8%,92.2%,95.8%,98.3%.In addition,all the tested rates were safe to wheat.Overall,QYM102 had high herbicidal activity in most of the broadleaf weeds in wheat field,and QYM102 had good safety to wheats,the mixture of QYM102 and fluroxypyr-mepthyl can expand the weed control spectrum.These findings suggested that QYM102 had a good application prospect in wheat.