POLYPROPYLENE ROW COVER IN PESTICIDE-FREE PRODUCTION OF STRAWBERRY IN FINLAND
The effect of row cover on the yield and incidence of pests and diseases of six strawberry (Fragaria × ananassa) cultivars was studied in 1986–1990, with no application of pesticides. Half of the plots were covered with polypropylene from the beginning of the growing season until the beginning of flowering, and again after harvest until mid-September. The cultivars Hiku, Mari, and Ostara yielded more than Senga Sengana, Zefyr, and Jonsok. The row cover accelerated crop ripening, but had only a minor effect on marketable yield and its value. In 1990, the row cover decreased (in 2 years) and increased (in 1 year) the incidence of fruit diseases, m mainly gray mold (Botrytis cinerea) on Hiku, the latest cultivar. The row cover tended to decrease the incidence of powdery mildew (Sphaerotheca macularis fsp. macularis) on young plants and stem-end rot (Gnomonia comari). The cover increased numbers of two-spotted spider mites (Tetranichus urticae) in spring, and in the last year increased injury caused by the strawberry blossom weevil (Anthonomus rubi) was observed.
Dalman, P., Parikka, P. and Touvinen, T. (1993). POLYPROPYLENE ROW COVER IN PESTICIDE-FREE PRODUCTION OF STRAWBERRY IN FINLAND. Acta Hortic. 348, 489-492