Abstract
Coriander (Coriandrum sativum L.) cultivars S-33, RD-44, and CO-2 were tested to determine the effect of number and timing of dinocap treatments on powdery mildew (Erysiphe polygoni DC) and essential oil yields. Generally, four and three applications of dinocap provided satisfactory control of the disease in the late- and early-maturing cultivars, respectively. However, these could be further reduced to three and two if the sprays are timed at flowering (F), seed formation (SF), and full fruiting (FF) stages in the late-maturing cultivars and at SF and FF stages in the early-maturing cultivars. Yield of these plots were statistically at par with the preventive fungicide treatment (applications at 10-day intervals from the pre-flowering stage until maturity). The results also indicated that pre-flowering applications did not contribute much in managing the disease.