Control Effect of Different Pesticides on Rice Seedling Blight in Mechanized Transplanting Rice Fields

doi:10.3969/j.issn.1005-6114.2025.03.013

Abstract：To effectively control the occurrence of rice seedling blight during the concentrated seedling cultivation process of early rice mechanized transplanting, this study investigated the effects of the pesticides imazalil and cyproconazole on seedling growth and the control effect on rice seedling blight under different seed soaking times and when combined with five types of seed dressing agents. The results showed that the tested pesticide treatments had a certain inhibitory effect on the early growth of seedlings, and some seed soaking treatments led to a decrease in the seedling survival rate. The pesticide treatments had a significant control effect on rice seedling blight, delaying the onset of disease. Soaking seeds for 72 hours showed a higher control effect than soaking for 24 or 48 hours. The control effect of cyproconazole soaked for 72 hours reached 93.21%, which was significantly higher than that of imazalil at 79.64%. In the treatment combining seed soaking and seed dressing, the control effect of imazalil soaking combined with seed dressing was significantly higher than that of single imazalil soaking. Considering the control effect, seedling survival rate, cost of pesticide application, and the need to control other diseases in early rice seedling fields, it is recommended to use the following combinations for seed treatment: 25% cyproconazole SC diluted 2000 times for 72 hours soaking + 24% benzovindiflufen + prothioconazole + thiamethoxam FS 500 mL/100kg seeds for dressing; 25% cyproconazole SC diluted 2000 times for 72 hours soaking + 10% metrafenone + prothioconazole + pyraclostrobin FS 200 mL/100kg seeds for dressing; 25% cyproconazole SC diluted 2000 times for 72 hours soaking + 25 g/L fludioxonil FS 500 mL/100kg seeds for dressing; or 450 g/L imazalil EW diluted 1800 times for 72 hours soaking + 62.5 g/L metrafenone + fludioxonil FS 300 mL/100kg seeds for dressing.