The efficacy of the mixture of azoxystrobin and difenoconazole on the control of both watermelon-anthracnose and watermelon Fusarium wilt and the improvement of watermelon qualities
Abstract:The mycelial growth inhibition method and spore germination inhibition method were used to assess the efficacy of the mixture of azoxystrobin and difenoconazole to control Fusarium oxysporum f.sp. nveum and Colletotrichum lagenarium. Experiment results showed the mixture at the rate of 1∶ 2 (azoxystrobin∶ difenoconazole) could take the best efficacy on the inhibition of mycelial growth and spore germination. The CTC of the mixture to inhibit the mycelial growth of Fusarium oxysporum f.sp. nveum and Colletotrichum lagenarium was 220.81 and 242.64 respectively. The CTC to inhibit the spore germination of two pathogens was 282.73 and 547.56 separately. The concentration of 0.12gai/L of the mixture could take the best effect. The prevention and therapy effect on the watermelon-anthracnose in the greenhouse was 78.20% and 73.00%, respectively. Meanwhile the therapy effect in the field was 76.48% and 76.32% separately. Furthermore, in the greenhouse the prevention and therapy effect on watermelon Fusarium wilt was 79.16% and 83.33%, while in the field the therapy effect after two and three times treatment was 77.27% and 71.43%, respectively. In addition, the mixture of azoxystrobin and difenoconazole with concentration of 0.12g ai/L could improve the watermelon s quantities of vitamin C, sugar, soluble solid product, with the increasing ratio of 51.16%,13.64%,15.45% and 22.58%, respectively.