| Phytophthora was a kind of worldwide distribution plant pathogen and caused severe diseases on crops, fruits, trees, ornamental plants, herbs and shrubs. Phytophthora often infected roots of plants, root cervical, leaf, flower and fruit and caused some symptoms such as root rot, root cervical and fruit rot, canker, wilting and spots. One of the useful measure to control Phytophora was to screen powerful fungicides.Five plant extracts 50% Theaflavin,90% Panax Notoginsenosides, 80% Baicalin,80% Gynostemma extract and Eugenol after diluted 1250 times were assayed their inhibition to several plant pathogenic fungi. The result showed that Eugenol was a potential botanical fungicide to control Phytophthora blight.The toxicity test showed that EC50 of 3g/Kg Eugenol and 25% metalaxyl-propamocarb hydrochloride to Phytophthora capsici were 0.0851 and 23.8451μg/mL, respectively. Based on EC50,3g/Kg eugenol was better inhibition ability to control Phytophthora blight than 25% metalaxyl-propamocarb hydrochloride.Field efficacy trials showed that:3g/Kg Eugenol and 25% metalaxyl-propamocarb hydrochloride could control Phytophthora blight. Control efficacy were over 70% to control Phytophthora blight after 3g/Kg Eugenol was diluted 2000 times and 25% metalaxyl-propamocarb hydrochloride was diluted 1000 times. |
