Abstract:

Through field experiments, the effectiveness of fungicides for wheat scab control is evaluated to provide reference on fungicide selection for plant protection departments. Taking ‘Zhenmai 12’ and ‘Zhenmai 9’ as the test varieties, the highest registered dose of the tested fungicides was applied twice at the flowering stage of wheat. The disease index of wheat scab and DON toxin content in grains were investigated 25 days after the last application, and the control effect of each fungicide on scab was calculated. The results showed that when the resistance frequency of wheat scab to carbendazim in an area reached more than 50%, the control effect of carbendazim on wheat scab declined from 90% to less than 80%; while when 75% trifloxystrobin·tebuconazole SC, an agent that contained strobilurin, was adopted to control wheat scab, the accumulation of DON toxin in wheat grains would be stimulated. The toxin content came up to 1.405 mg/L, which was higher than 0.598 mg/L of CK. Moreover, the minimum effective dose of tebuconazole for wheat scab prevention and control in this area was preliminarily determined to be 120 g/hm² by effectiveness monitoring. Monitoring the effectiveness of fungicides is a key safeguard mechanism for the effective prevention and control of wheat scab.

Key words: wheat scab, fungicide for disease control, effectiveness monitoring, DON toxin, control effect