Sensitivity of Walnut-associated Alternaria alternata to Four Fungicides

[Methods]The sensitivity of walnut-associated Alternaria alternata to four fungicides was determined by mycelia growth rate test and conidial germination assay.[Results]The results indicated that all tested fungicides had good inhibition of mycelia growth.Prochloraz was the most effective,with the EC50 of(0.7512±0.6551) mg/L,followed by iprodione and tebuconazole with the EC50 of(1.6367±0.7887) and(1.78±0.4302) mg/L,respectively.The sensitivity of conidial germination to the tested fungicides was lower than that of mycelia growth,with the EC50 values of more than 40 mg/L.Prochloraz caused the biggest difference of the sensitivity to both mycelia growth and conidial germination of tested strains.[Conclusions]Blending or alternatively applying prochloraz and/or iprodione could be adopted as effective fungicides for integrated management of disease caused by A.alternata in walnut orchards.