Influence of spray schedules on fungicide resistant populations of Botrytis cinerea Pers. on grapevine

Abstract

Treatments with dicarboximide fungicides provided only 20 to 40o70 control of grey mould on grape (cv. Moscato d'Asti) in vineyards where benzimidazole and dicarboximide resistant strains of Botrytis cinerea Pers. constituted about 50~ of the fungal population and a high disease pressure existed. The percentage of dicarboximide resistant strains increased after treatment. Fungicide combinations of a benzimidazole with diethofencarb, sprayed twice per season or once alternated with a dicarboximide, provided satisfactory control of grey mould and decreased the percentage of benzimidazole resistant strains. A combination of thiram and procymidone controlled grey mould, but increased dicarboximide resistance in the population.

Integrated Control of Botrytis Cinerea on Greenhouse Tomatoes

“…The aim of maintaining satisfactory levels of control in the presence of strains resistant to one of the fungicides used in the alternation, and of preventing an increase in the incidence of resistance, was sometimes achieved for certain combinations of multisite fungicides with dicarboximides or benzimidazoles (e.g. Gullino and Garibaldi, 1982;L6cher et al, 1987;Northover, 1988;Gullino et al, 1989). The implementation of such strategies in the context of greenhouse vegetable production is attractive, but complicated by the small number of chemicals available for control (Gullino and Kuijpers, 1994).…”

Multiple Fungicide Resistance in Botrytis: A Growing Problem in German Soft-Fruit Production

“…In general terms, broad-spectrum fungicides such as tolylfluanid, chlorothalonil, folpet or thiram possess a lesser efficacy against B. cinerea than single-site fungicides (Gullino et al, 1989;Singh & Milne, 1974;, but they are also less susceptible to resistance development (Leroux, 2007). Future experiments should focus on examining their impact on the development of resistance against the current single-site fungicides when applied as tank mixtures.…”

“…Future experiments should focus on examining their impact on the development of resistance against the current single-site fungicides when applied as tank mixtures. Detailed experiments under regional conditions are required because previous workers have obtained heterogeneous results (Gullino et al, 1989;Hunter et al, 1987;Northover & Matteoni, 1986). If a suitable broad-spectrum fungicide can be found, this should be registered for grey mould control with some urgency.…”

Botrytis cinerea in greenhouse vegetables: chemical, cultural, physiological and biological controls and their integration

“…They are less effective than the specific fungicides employed against grey mould, but are common in anti-resistance strategies. Mixtures of fungicides or rotation in their use may help to reduce the spread of resistance Gullino et al 1989). New compounds are being tested for Botrytis control (Gullino 1992) and may add new tools for chemical control of the disease.…”