The aim of this study was the estimation of blossoming of 14 apricot cultivars in Boldogkôváralja in 2009, 2010 and 2011 seasons. And this will help growers to select appropriate varieties to their weather conditions. For this target the blooming period of 19 apricot varieties of different origin was observed in three subsequent years. There...was no large difference in the beginning of blooming in the different years, and the greatest variation between the start date of flowering was about 1 to 3 days as the place of experiment site near to northern border and also, length of flowering period of apricot trees is also inversely related to date when blooming started. The little differences in flowering dates and flowering periods due to the high temperature through the three seasons of study.
There are four apricot varieties grown in Hungary derived from local selections known to bear fruits of giant (60 - 100 g) size: Ceglédi óriás, Nagykőrösi óriás, Szegedi mammut and Ligeti óriás. Being morphologically similar, they seem to be closely related to each other. The detailed study of the morphology (of leave...s and fruits) and phenology (of blooming and ripening dates) as well as the fertility relations was aimed to find out the degree of kinship between the varieties in question.
It was stated that the value of morphological traits is variable from the taxonomic point of view. The most important signs of common origin were the time of blooming and the leaf size. Less valuable are the date of m:iurity and the size of fruit because of their variability. In the literature Satin') & Nyeki (1991) published the first proof of inter-incompatible relation between apricot varieties. This should be considered as an argument of close genetic relation between those "giant" varieties of apricots.
The first three varieties. Ceglédi óriás, Nagykőrösi óriás and Szegedi mammut are closer related in blooming and ripening date, as well as in size of fruit to each other than the variety Ligeti óriás.
Information concerning the blooming time of stone fruit varieties is, first of all, an important condition of finding suitable pollinisers securing adequate fruit set. For that purpose, varieties are assigned to blooming-time-groups. Depending on the number (3 or 5) of the groups, i.e. the length of intervals separating the groups established,...pollenisers are to be chosen for self-incompatible and partially self-fertile varieties belonging to the same blooming-time-group. The mutually most overlapping blooming periods of the respective varieties should be found by raising data of their blooming phenology, i.e. dynamics, which is compared by drawing their phenograms and calculating blooming (V) indices. Variety combinations have to be checked, however, concerning mutual fertility relations of the respective pairs of varieties. That is most important in the case of Japanese plums because of the abundant incompatible combinations. Synchronous blooming has been determined by assigning the varieties to blooming-time-groups, or comparing overlaps of blooming phenograms, or by blooming (V) indices. Synchronous blooming phenology has been studied in European plum varieties (111 varietiy combinations) Japanese plums (156 variety combinations) and apricots (153 variety combinations) under Hungarian conditions, over several seasons. In determining overlaps, the less favourable season has been considered as decisive. Polliniser combinations have been chosen with at least 70% synchronous blooming. Blooming time of varieties is an important part of the variety descriptions. Blooming dates may serve also for the estimations of frost risk or security of yield.