Influence of Prohexadione-Calcium and Ethephon on Vigor of Sweet Cherry Cultivars

Abstract

In Serbia, in the majority of sweet cherry orchards, vigorous rootstocks (Mazzard and Mahaleb seedlings and clonal rootstock ‘Colt’) are used. Cherry trees grafted on these rootstocks are characterized by vigorous growth and the subsequent late coming into bearing. The aim of this study was to examine the effect of the combined use of two bioregulators: Prohexadione-calcium and Ethephon on vigor of sweet cherry cultivars. Studies were carried out in a cherry orchard in Grocka (near the Belgrade) on five cultivars: ‘Bigarreau Hatif Burlat’, ‘Sunburst’, ‘Carmen’, ‘Kordia’ and ‘Regina’ grafted on the rootstock ‘Colt’. There were two treatments with Prohexadione-calcium (250 mg/l) and Ethephon (175 mg/l). The first treatment was done when the shoots were 8-10 cm long, and the second one three weeks later. At the end of the growing season were conducted measurements of the following parameters: length of shoots, diameter of shoots, number of nodes per shoot, leaf area, and the number of spurs per tree. All parameters of vigor had less values on the trees treated with bioregulators. Length of the terminal shoots on treated trees was lower by 24-35% comparing to control. In addition, bioregulators influenced significant increase in the number of spurs (by 12-74%) in all tested cultivars, except for the cultivar ‘Burlat’.

Cilj ovog rada je bio ispitivanje uticaja kombinovane primene dva bioregulatora: proheksadion-kalcijuma i etefona na bujnost sorti trešnje. Ipitivanja su obavljena u proizvodnom zasadu trešnje u Grockoj na pet sorti: Burlat, Karmen, Sanberst, Kordija i Regina okalemljenih na podlozi Kolt. Tretman bioregulatorima je obavljen u proleće u dva navrata: početkom i krajem maja. Na kraju vegetacionog perioda izmereni su sledeći parametri: dužina i prečnik letorasta, broj nodusa, dužina internodija i površina lista. Svi ispitivani parametri bujnosti su, u manjoj ili većoj meri, imali manje vrednosti na stablima na kojima je obavljeno tretiranje bioregulatorima. Pored toga, bioregulatori su uticali na značajno povećanje broja formiranih majskih buketića kod svih ispitivanih sorti, osim kod sorte Burlat.