Effects of developmental stage of watermelon on fungicidal control of anthracnose.
X. G. ZHOU and J. A. Duthie.
Phytopathology 89:S90. (suppl.)
1999
บทคัดย่อ
The effectiveness of fungicidal control of anthracnose caused by (Colletotrichum orbiculare) varies with the developmental stage of the crop but this variation has not been assessed critically. In field experiments that conducted over two years, treatments were arranged in a split plot design. Three dates of planting were randomized to whole plots. Weekly applications of chlorothalonil were initiated at the stage of vining, flowering, fruiting, or control consisted of no fungicide application as subplots. An epidemic was initiated in each plot when plants in plots assigned to the first, second, and third planting date had reached the stage of the fruiting, flowering, and vining, respectively. The effectiveness of chlorothalonil varied considerably with the developmental stages at which applications and epidemics were initiated. Chlorothalonil was most effective when applications were applied prior to the crop stage at which epidemics were initiated; otherwise it was least effective. Application initiated at the flowering stage was sufficient to control anthracnose regardless of when epidemics started.