RIPENING TIME OF PEACH CULTIVARS IN THE CENTRAL PART OF HUNGARY IN A LONG-TERM OBSERVATION.

The ripening time of peach cultivars is genetically determined, but it is greatly influenced by environmental factors. Prediction of ripening time is very useful from a scientific point of view and for practice as well. Generally, the sum of temperature and the days from flowering to ripening are used for prediction. Our work examined the phenological characteristics of 50 peach cultivars for 26 years in our experimental plantations in the central part of Hungary. We found that the number of days from flowering to ripening and the heat units (temperature sum units) vary greatly from year to year, so these values are not suitable for accurate prediction of the ripening time of cultivars. From a practical point of view, using reference cultivars is more effective for growers. The gradual shift towards earlier ripening time is proved during 26 years. Depending on the cultivar, the starting date of ripening of the investigated peach cultivars was 0.28 to 0.36 days earlier each year in our experimental plantations. [ABSTRACT FROM AUTHOR]