Forma korony a uszkodzenia mrozowe pędów i pąków kwiatowych drzew brzoskwini

The experiment was conducted at the Experimental Fruit - Growing Station in Samotwór, belonging to the Wroc ł aw University of Environmental and Life Sciences. The aim of the study was to determine the extent of damage to the shoots and flower buds of peach trees after the winter of 2009/2010, when the temperature fell to - 24 to - 26 o C. Under evaluation were six - year - old trees of the cultivars ‘Redhaven’ and ‘Inka’ grown at a spacing depending on the type of canopy: 4 x 3 m (open vase), 4 x 1 m (vertical axis), and five - year - old trees of ‘Suncrest’ and ‘Cresthaven’ grown at 3.5 x 1 m (vertical axis), 3.75 x 2 m (spindle), and 4.25 x 3 m (open vase). The degree of damage to one - year - old shoots was estimated by using a five - point scale according to Ho ł ubowicz’s test. Flower buds were dissected and divided into two groups (healthy and damaged). The shoots under assessment came from the top and bottom part of the crown. The trees were of different heights, depending on the form of the crown. The highest trees were trained in the form of a vertical axis and the lowest as an open vase. The temperature of - 24 o C did not cause large differences in the degree of damage to the shoots of ‘Inka’ and ‘Redhaven’ trees in relation to the type of crown. Only in the case of ‘Redhaven’ trees, greater damage to lower shoots was noted in the open vase system in comparison with vertical axis. Following the - 26 o C frost, the crown form was found to have no effect on the extent of damage to t he lower shoots of 'Suncrest' and 'Cresthaven' peach trees. Only in the case of the shoots at the top of the tree, more serious damage was found in 'Cresthaven' trees shaped as an open vase. Irrespective of the crown shape, the low temperatures had caused severe damage to flower buds in the lower part of the crown. In the upper part of the crown, considerably fewer damaged buds were found in the taller trees shaped as a vertical axis in comparison with the shorter ones shaped as an open vase.