Panicle

Myclobutanil

Biology

Azoxystrobin

Fungicide

Propiconazole

Tebuconazole

Toxicology

Agronomy

Horticulture

Mancozeb

Carbendazim

Scientific Reports

In this study, the fungicidal activities of the fungicides azoxystrobin, difenoconazole + propiconazole, carbendazim, flutriafol, fluopyram + tebuconazole, mancozeb and thiophanate-methyl against rice blast and dirty panicle pathogens were evaluated under laboratory and field conditions. Mancozeb exhibited the highest level of fungicidal activity against the blast pathogen Pyricularia oryzae , with an EC 50 value of 0.25 parts per million (ppm). The combination of two fungicides, fluopyram + tebuconazole, showed the strongest fungicidal effect against Bipolaris oryzae and Curvularia lunata , with EC 50 values of 0.587 ppm and 0.435 ppm , respectively. Meanwhile, carbendazim and flutriafol demonstrated the best level of fungicidal activity against Fusarium incarnatum , with the lowest EC 50 values of 0.211 ppm and 0.214 ppm , respectively. The results showed that the fungicides, triazole and strobilurin, had significant effects against rice blast and dirty panicle diseases. The combination of fluopyram + tebuconazole, when applied twice, was the most effective in reducing dirty panicle disease by up to 60% and increasing rice yield by 29% more than the untreated control. Fluopyram + tebuconazole, difenoconazole + propiconazole, flutriafol and azoxystrobin achieved stronger fungicidal activity against rice blast disease, reducing its severity by 32–33% when applied twice by foliar spraying. However, carbendazim, mancozeb and thiophanate-methyl had low to moderate fungicidal activity against both rice diseases in this study.

Efficacy of fungicides in controlling rice blast and dirty panicle diseases in Thailand