几种杀菌剂防控小麦赤霉病穗腐及籽粒脱氧雪腐镰刀菌烯醇(DON)毒素的评价

小麦赤霉病是小麦穗期的主要病害之一。化学防控一直是小麦主产区防控赤霉病的主要措施。为明确几种新型杀菌剂对小麦赤霉病的防效和对小麦籽粒DON毒素含量的影响,于2018年进行了氰基丙烯酸酯类和三唑类杀菌剂单剂及其复配剂对赤霉病的防效试验。结果表明:30%戊唑·多菌灵悬浮剂(SC)1500 mL/hm^2处理对赤霉病病穗防效达92.40%,病指防效达93.20%,小麦籽粒DON毒素检出量较不用药对照降低80.38%;25%氰烯菌酯SC 2000 mL/hm^2处理对赤霉病的病穗防效达86.80%,病指防效达88.78%,小麦籽粒DON毒素检出量较不用药对照降低88.19%;48%氰烯·戊唑醇SC 900 mL/hm^2和40%丙硫·戊唑醇SC 600 mL/hm^2对小麦赤霉病的病穗防效分别为77.20%、78.00%,病指防效分别为80.27%和79.59%,对籽粒DON毒素检出量较不用药对照分别降低73.87%和81.42%。在小麦赤霉病较重发生的情况下,上述4种杀菌剂单剂或复配剂1次用药既能高效控制病情,又能有效控制小麦籽粒DON毒素不超标。本试验研究进一步阐明,氰烯菌酯、戊唑醇、丙硫菌唑等杀菌剂及其复配剂均能有效控制小麦赤霉病的危害,并能有效降低小麦籽粒DON毒素含量;吡唑醚菌酯单剂及其复配剂虽然对小麦赤霉病的病穗和病指防效也较高,但控制小麦籽粒DON毒素含量效果相对较差。研究结果为小麦穗期赤霉病化学防控提供了科学参考。

Evaluation of several fungicides for controlling the Fusarium head blight and deoxynivalenol content in wheat grain

Fusarium head blight is one of the main diseases at wheat earing stage, and chemical control has been the main measure to control the wheat scab in the main wheat producing areas. To clarify the control effects of several new fungicides on Fusarium head blight and deoxynivalenol (DON) concentration in wheat grain, the experiment of single agent of cyanoacrylate and triazole fungicide and its compounded agent against Fusarium head blight were carried out in 2018. The results showed that tebuconazole·carbendazim 30% SC 1 500 mL/hm2had the best control effect on Fusarium head blight, the control efficacy on diseased ears rate was 92.40%, the control efficacy on disease index was 93.20%, and the decrease rate of DON compared to CK was -80.38%. In the phenamacril 25% SC 2 000 mL/hm2 treatment, the control efficacy on diseased ears rate was 86.80%, the control efficacy on disease index was 88.78%, and the decrease rate of DON compared to CK was -88.19%. In the other treatments, phenamacril·tebuconazole 48% SC 900 mL/hm2 and prothioconazole·tebuconazole 40% SC 600 mL/hm2had a better control effect on Fusarium head blight and DON content in wheat grain, the control efficacies on diseased ears rate were 77.20% and 78.00%, the control efficacies on disease index were 80.27% and 79.59%, the decrease rates of DON compared to CK were -73.87% and -81.42%, respectively. In the case of heavier occurrence and damage of wheat scab, the four kinds of fungicides single or compounded agent above not only controlled the disease, but also controlled the DON toxin in wheat grain not exceeding the standard. This experiment further clarified that the single agent of phenamacril, tebuconazole and prothioconazole and their compounded agent could not only effectively controlled the damage of wheat scab, but also could effectively reduce the DON toxin in wheat grain. Although the single agent of pyraclostrobin and its compounded agent had higher control efficacy on the diseased ears rate and disease index, the effect of controlling the content of DON toxin in wheat grain was relatively poor. The research results provide a scientific reference for chemical control of wheat scab.