Control Of Gray Mould (Botrytis Cinerea) On Strawberry Fruits By Foliar Spray Of Mono-Potassium Phosphate

Mona A. El-Shamy and Shawky M. El-Desouky
Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt
E-mail: monash512@hotmail.com

Abstract

A foliar spray of 1% (w/v) solution of mono-potassium phosphate (MKP), applied at two weeks interval starting from flowering till the end of the fruiting stage, on fruiting strawberry grown in the open field, significantly reduced both the disease incidence and disease severity of gray mould (Botrytis cinerea). This was expressed by a reduction in fruit area covered with sporulating colonies, and in conidia production on fruit tissues. The efficacy of MKP was compared with that of other salts i.e. sodium bicarbonate, ammonium bicarbonate and calcium chloride as well as with fungicides recommended to control the disease. All treatments significantly inhibited gray mould development as compared with the non-treated controls. A remarkable control of strawberry fruit gray mould was obtained when strawberry fruits were sprayed with mono-potassium phosphate, followed by sodium bicarbonate while ammonium bicarbonate and calcium chloride were the least effective treatments. Microscopic examination suggested the destruction of fungal hyphae and conidia structures in MKP-treated fruits. Phosphate solutions were not phytotoxic to plant tissues, and had no residual effects in fruit yield. Lower yields were recorded in non-treated control plots due to fruit infection. It is suggested that MKP may be used as an alternative practice to control gray mould on strawberry fruits at a commercial scale.