Toxicity assay and field control effect of several chemicals against corn stalk rot.

The biological activities of nine different chemicals comprising of single-dose and mixtures were tested against the corn stalk rot pathogens by toxic media method in lab.The results indicated that both Azoxystrobin and Metalaxyl showed strong toxicity against Phthium graminicola,and EC50 for mycelial growth was 0.57mg/kg and 0.58mg/kg respectively,besides,the toxicity of Maxim and Difenoconazole against Phthium graminicola was also strong.Fludioxonil,Maxim,Carbendazim and Difenoconazole showed strong toxicity against Fusarium graminearum,and the EC50 for mycelial growth was 0.03mg/kg,0.30mg/kg,0.56mg/kg and0.89mg/kg respectively.The corn seeds treated with above chemicals have certain control effect on corn stalk rot.