Production weight and its variability in 24 apricot genotypes over six years

Productivity and its stability were evaluated in a set of 24 apricot genotypes of the world collection and some promising new selections in 1994-1999. The productivity of most genotypes was higher than that of control variety Velkopavlovická LE-6/2. Genotypes with higher productivity in the years favorable for apricot productivity gave higher yields also in the years unfavorable for productivity. It was proved by a significantly close highly significant correlation (r = 0.64++). It is a reason for the necessary regulation of fruit set in highest-yielding varieties in the years favorable for apricot productivity when overproduction and undesirable reduction in the fruit size occur. The variability of yields in kg per tree, expressed by coefficients of variation over a six-year period, was high in the years of observation. The variability of yields was significantly lower in the years favorable for apricot productivity. To express yield variability the coefficient of variation and index of fluctuation can be used. Their similar conclusiveness was proved by the significant positive closeness of correlation between the values determined by both calculations (r = 0.51+). The varieties Vynoslivyj and Volšebnyj showed the highest and most stable productivity. From the producer's and breeder's aspects, of these two the Vynoslivyj variety is one of the most remarkable genotypes of the evaluated set due to its fruit quality and late ripening.