Folia Horticulturae

Current issue content   Search      

Effect of paclobutrazol on certain properties of fruits of the apple of cvs. Jonagold and Gloster

Jan Ben, Władysław Poniedziałek

Department of Pomology
Faculty of Horticulture, Agricultural University
29 Listopada 54, 31-425 Kraków, Poland

Jonagold and Gloster trees on MM 106 and M 26 rootstocks were sprayed with paclobutrazol for three successive years at different times and at various concentrations. Some parameters of fruits were determined at their harvest maturity phase. An increase in colouring of fruits was observed in 1991 on Jonagold trees grafted on MM 106 in all treatments with paclobutrazol as compared with those on control trees. Apples of the same cultivar on M 26 increased their colouring as a result of four-fold spraying of the trees with paclobutrazol at a concentration of 250 mg l-1, and twice spraying at 500 mg l-1 during green inflorescence and the end of blooming. An incraese in the colouring of fruits was visible on Gloster trees on M 26 but only in the treatment in which the subsequent effect of spraying applied in 1989 was studied. In 1991, a larger blush area was noted on the fruits of Gloster trees on MM 106 rootstock when paclobutrazol at 100 mg l-1 was used three weeks after the end of blooming and on fruits of trees on M 26 rootstock sprayed four times beginning from green inflorescence, after blooming, and 10 or 20 days later. In both years, the mean fruit weight of Jonagold trees as a rule decreased from trees on MM 106 sprayed after full bloom with paclobutrazol at a concentration of 500 mg l-1 and higher. Fruit with a smaller mass often showed better flesh firmness. An increase in the mass density of Jonagold apples was also most frequently achieved with higher concentrations of paclobutrazol after full bloom.

Ben J., Poniedziałek W., 1994. Effect of paclobutrazol on certain properties of fruits of the apple of cvs. Jonagold and Gloster. Folia Horticulturae VI/1: 73-81.