Inhibition of strobilurin fungicides against Phytophthora capsici.

Four commercial formulations of strobilurin fungicides,kresoxim-methyl,azoxystrobin,enestroburin and pyraclostrobin were evaluated for their efficacy,curative and protection action against pepper phytophthola blight caused by Phytophthora capsi-ci.The results in vitro showed that 4 fungicides including kresoxim-methyl,azoxystrobin,enostroburin and pyraclostrobin could inhibit the mycelium growth of Phytophthora capsici with their EC50 at 8.88,34.64,125.90,17.04 ug·mL-1,respectively.Spo-rangium formation of Phytophthora capsici was inhibited significantly by 4 fungicides with their EC50 at 1.31,3.43,6.92,1.92 ug.mL-1.4 kinds of fungicides showed stronger inhibition against sporulation germination with their EC50 values at 0.94,2.50,1.73,0.76ug·mL-1.The results in vivo showed that these fungicides showed more protective and curative activities and protection action was better than curation.Control efficacy of 4 fungicides used before infection of Phytophthora capsici have reached more than 67.9 percent.