CERCOSPORA BETICOLA INSENSITIVITY IN MICHIGAN AND MICHIGAN SUGAR COMPANY'S RESISTANCE MANAGEMENT STRATEGIES

摘要

Cercospora leafspot, caused by the fungus Cercospora beticola, is the most serious ioliar disease of sugarbeets in Michigan. Research trials conducted in Michigan show that poorly controlled Cercospora leafspot (25 to 50% canopy desiccation) resultedin losses of 2 to 4 tons per acre and from 0.25 to 1.0 point of sucrose. The disease is managed with an integrated program which includes proper rotations, varietal tolerance and fungicide sprays. Most of the varieties in Michigan have relatively good tolerance to Cercospora; however, our highest producing varieties are quite susceptible to the disease.