토마토 잎마름역병 발생 예측 및 방제 시기 연구

Tomato leaves were inoculated with 1x104 spores · mL-1 and placed in an acryl box at 10, 15, 20, 25, and 30oC for 24 h. Ten days after inoculation, the incidence of late blight appeared as a typical symptom in 6 hrs treatment of leaf wet duration when the temperature is between 15 and 20oC at that time. The incidence of disease was 26% and 41% at 10oC and 25oC treatment although the disease did not occur even after treatment at 30oC for 16 h, respectively. The most important factors in the incidence of Late blight were leaf wet duration and temperature. Optimum growth temperature of tomato is from 15 to 25oC, thus the management of leaf wet duration is better than control by temperature to prevent the incidence of Late blight. After inoculation, the symptoms of Late blight occurred in 5 days, therefore the latency period was estimated to be 5 days. The incidence rate of Late blight was the highest at 15 and 20oC. At the time of chemicals application, when Fluopicolide 5%+Propamocarb hydrochloride 25% was applied at 12 h of leaf wet duration, the control effect was the highest as 95% at 36 h but decreased by 70% when treated after 48 h. On the other hand Cymoxanil 12% + Famoxadone 9% was applied at 18 h of leaf wet duration, the control effect was the highest as 95% at 36 h but decreased by 70% after 48 h as similar as Fluopicolide 5% +Propamocarb hydrochloride 50% treatments. In the application of Dimethomorph 15% +Dithianon 30%, the control effect was more or less low as 80% at 20 h of leaf wet duration and was decreased to 60% at 48 h.