THE SENSITIVITY OF STRAWBERRY CULTIVARS TO MAJOR FUNGAL FOLIAR DISEASES IN CROATIA, AND THE POSSIBILITIES FOR THEIR CONTROL

Abstract

In Croatia, the production of strawberries has been increasing steadily in recent years. The assortment has been changing from year to year, owing to the introduction of new cultivars.The most important common cultivars in production are: Elsanta, Marmolada, Miranda, Maya, Madeleine, Miss and Raurica. The aim of our research was to determine the sensitivity of these cultivars to major fungal diseases of leaves in Croatia, namely leaf spot (Mycospahaerella fragariae), leaf scorch (Diplocarpon earliana), leaf blotch (Gnomonia comari), and leaf blight (Phomopsis obscurans). In order to determine the possibilities for controlling these diseases, we conducted tests foof fungicide efficacy on the most sensitive cultivars. The infection intesity of each disease was assessed according to the Townsend-Heuberg formula based on an analysis of 200 leaves and our own scale of 0-5, while fungicide efficacy was determined by Abbotts formula. Among the cultivars tested for leaf spot, the most sensitive cultivars were Madeleine and Marmolada, while the other cultivars were relatively resistant to this disease. The cultivar most sensitive to leaf scorch was Raurica and somewhat less, Marmolada. All cultivars proved to have a low sensitivity to leaf blotches and leaf blight. Among the fungicides, Folicur M and Euparen M had the best eficacy for all tested diseases. Kidan had a good efficacy on leaf scorch, as did Quadris on leaf spot. Based on the results obtained, we created a leaf protection plan, dependant on the cultivars grown.