Effect of irrigation on fruit quality and yield of ʻRed Capʼ apple cultivar depending on crop load

Effect of irrigation on fruit quality and yield of Red Cap apple variety depending on crop load were studied. The aim of the paper is to determine how many apple fruits can be left on trees in third vegetation, growth under different irrigation treatments (without irrigation, normal irrigation - control and increased irrigation - double irrigation rate). For the Red Cap variety in the third year after planting, in order to achieve good fruit quality and satisfactory yield, it is necessary to leave a maximum of 25 fruits per tree, or 3.5 fruits per cm2of trunk cross-sectional area (TCSA). Different irrigation treatments have influence on the fruit size, the proportion of first class fruits, as well as the degree of ripeness of the fruits. Increased irrigation during the months of July and August affects these parameters, but to a lesser extent than the crop load. The largest irrigation effect on the increase of fruit size had trees from crop load III, who had 5,5 fruits per cm2 of TCSA. Increased irrigation during July and August had no statistically significant effect on tested parameters on trees that had less than 4,5 fruits per cm2 of TCSA and trees that had more than 6,5 fruits per cm2 of TCSA