Correlative relation of yield and fruit quality with some phenological phases in peach

Ripening time of peach cultivars that are grown up in our country is extended over a time period of almost four months. In addition to that, one of more important objectives of the peach breeding is creation of the cultivars having either very early or very late ripening time. Our so far experience is that the peach cultivars which ripening time is in the extremes is of lower fruit quality. The aim of this study, therefore, was to determine relationship and the nature of the dependence between flowering time or ripening time from one side and yield, yield components (initial and final fruit set, fruit weight and stone weight) and chemical composition of fruit (content of total dry matter, content of soluble solids, content of total, invert and reduced sugar and content of total acid) on the other side. Twenty peach cultivars each having a different ripening time were using as material. The relationship between characteristics was determined on the basis of values of genetic and phenotypic correlation coefficients. Genetic and phenotypic coefficients of correlation were calculated based on the results of monofactorial analysis of covariance where the years considered as replications. It was confirmed that flowering time was positive genetic and phenotypic correlated with initial fruit set and with final fruit set. The existence of significant genetic and phenotypic correlation between ripening time and fruit weight, between ripening time and dry matter content and between ripening time and soluble solid content represented difficulty in creation of new peach cultivars of early ripening time and improved fruit quality .