Modelling the phenological processes of dormancy in frost-sensitive stone fruit species in the central part of the Carpathian Basin.

摘要

The safety of fruit production depends to a great extent on developmental processes and frost tolerance during dormancy. This is especially true of early flowering, frost-sensitive stone fruit species. In the past 15 years, detailed examinations have been made on floral bud development, its effect on frost tolerance and on the relationship with environmental factors in various genotypes of three species, almond, apricot and peach, sampled from an experimental orchard located in the centre of Hungary, 30 km from Budapest. In addition to field tests a range of laboratory experiments were used to measure frost tolerance. Based on these data, models have been elaborated for phenological processes and for changes in the frost tolerance of floral buds in varieties of each fruit species representing different frost tolerance levels. Of the three fruit species, apricot genotypes, especially those with low demand for chilling units, are the most sensitive to temperature fluctuations, resulting in the largest seasonal effects on the floral bud development rate. Temperature influences the development rate of almond and peach to a smaller extent, though there are, nevertheless, large variations among the genotypes of these fruit species. Not only the floral bud development rate, but also the frost tolerance of overwintering organs, is strongly influenced by temperature changes during dormancy. No correlation has been found between these two plant characteristics, confirming their separate genetic determination. The models elaborated may promote (1) the evaluation of breeding materials and the selection of varieties suited to the Carpathian Basin and to areas with similar climatic conditions, and (2) the planning of technological measures necessary for increasing yield safety, improving the profitability of cultivating frost-sensitive stone fruit species as a potential outcome. In addition, these models provide basic information on the relationship between fruit trees and their environment and on the possible impact of climate change on floral bud development.