Pyrimethanil tolerance of Botrytis cinerea isolates from Egypt and Hungary.

Botryotinia fuckeliana (de Bary) Whetzel, anamorph Botrytis cinerea Pers.:Fr. causes severe damages in vineyards on the yield as well as on quality of grapes at harvest. Pyrimethanil (anilinopyrimidine fungicide class) have been used to control grey mould, the disease caused by this pathogen. The anilinopyrimidine were registered in Switzerland in 1995 to control grey mould in grapes. A dual mode of action has been described involving the inhibition of methionine biosynthesis and the inhibition of hydrolytic enzyme secretion. The anilinopyrimidines inhibit mycelial growth of fungus. The intensive use of anilinopyrimidines may result reduced sensitivity and loss of efficacy. Recently, a reduction in sensitivity to anilinopyrimidines in B. cinerea strains was also reported from France. In the last 35 years B. cinerea developed resistance to virtually all the specific fungicides used to control grey mould. Field resistance to benzimidazoles, phenylcarbamates and dicarboximides was detected shortly after their introduction. Therefore, an antiresistance strategy should be introduced for current fungicides as well. This study was initiated to study the resistance of B. cinerea to one of the main important class of modern fungicides, the anilinopyrimidines viz. pyrimethanil. This information will be useful to provide alternative fungicide options to the growers.