Abstract
In this experiment, the growth of peach and nectarine trees was determined to be related to the cultivar. ‘Inka’ peach trees grew weaker than ‘Harbinger’ trees. The ‘John Rivers’ nectarine was characterized by stronger growth than the ‘Harko’. The amount of crops produced by the trees was related to the cultivar and the meteorological conditions during winter and spring. ‘Inka’ produced higher yields and bigger fruits as compared to ‘Harbinger’. The ‘Harko’ cultivar provided significantly higher yields than the ‘John Rivers’ only in 2006. Peach and nectarine fruit production in the Sandomierska Plateau in the years 2004 − 2007 was risky. In 2006, damage to the flower buds during winter caused no crop yield in young peach trees and the older ones of the ‘Harbinger’ cultivar. A minor reaction to the temperature drop, down to -26.8oC, was found for nectarines in comparison with peach trees. In 2007, the spring frost injured flower pistils and caused a lack of crops from the studied cultivars.