APPLICATION OF ANTITRANSPIRANT AND REDUCED RATE FUNGICIDE COMBINATIONS FOR FRUIT ROT MANAGEMENT IN CRANBERRIES

Studies were conducted over a 3-year period to evaluate the efficacy o f reduced rate combinations of chlorothalonil and an antitranspirant ( AT), Wilt-PNf, for control of fruit rot in cranberries. Several reduce d rate combinations provided control comparable to that with the fungi cide used alone at suggested label rates of 0.76 to 1.34 liters/ha (4 to 7 pt/A) in field trials. In two trials, higher concentrations of th e AT (3 to 5%) had a detrimental effect on total and usable yield at h igher fungicide rates. The lowest tate of chlorothalonil that can be e ffectively used in combination with any tested rate of Wilt-Pruf is 0. 76 liters/ha (4 pt/A). Using 0 or 0.38 liters/ha (0 or 2 pt/A) with an y tested rate of the AT inadequately protected the berries against fru it rot infection. The incorporation of reduced rate combinations may o ffer the management advantage of lowered environmental risk per fungic ide application in certain situations.