Toxicity of fungicides to six pathogens of Fagopyrum esculentum in Gansu Province

Fungal diseases are a serious threat to buckwheat (Fagopyrum esculentum), affecting its yield and quality. This study aimed to determine the role of fungicides in preventing the most prevalent diseases of buckwheat in Gansu Province. For this purpose, the inhibitory effect of seven types of high-efficiency and low-toxicity fungicides on the mycelial growth of six targeted pathogens was studied. The results showed that 80% mancozeb (EC₅₀: 0.030 4 mg·L⁻¹), 80% carbendazim (EC₅₀: 0.049 0 mg·L⁻¹), 80% mancozeb (EC₅₀: 0.052 5 mg·L⁻¹), 20% difenoconazole·prochloraz (EC₅₀: 0.041 8 mg·L⁻¹), 40% pyrimethanil (EC₅₀: 0.068 4 mg·L⁻¹), and 80% mancozeb (EC₅₀: 0.010 5 mg·L⁻¹) had the strongest inhibitory effect on mycelial growth of pathogens such as Alternaria alternata, Botrytis cinerea, Botrytis polygoni, Bipolaris zeae, Hedymella rhei, and Stemphylium vesicarium, respectively. In addition, 80% mancozeb showed the highest inhibitory effect against five pathogens: Alternaria alternata, Botrytis cinerea, Botrytis polygoni, Didymella rhei, and Stemphylium vesicarium. This study provides comprehensive information on types of control agents and preventive fungicides as well as reference values for disease prevention and green buckwheat production.