CHLOROPHYLL FLUORESCENCE BASED COPPER TOXICITY ASSESSMENT OF TWO GRAPE VARIETIES

Abstract

Pesticides with copper active ingredient are commonly used in integrated grapevine pest management against downy mildew disease. It is known that copper can be toxic to young leaves. Different varieties have different sensitivity. In this research two grape varieties were examined regarding this problem. Narancsízű variety is a hybrid of Chasselas which is known to be sensitive to copper while Pannon frankos is a new variety whose sensitivity to copper is not known. This variety is very suitable for integrated grape growing. Chlorophyll fluorescence of the 3^rd and 5^th leaves was evaluated with MINI PAM in four days. F_o and F_m values were measured in 3 repetition and photochemical utilization (YII) was calculated. Significant differences were found in the inhibition of Y(II) between the two varieties by copper-hydroxide active ingredient.