Određivanje agroklimatski povoljnih zona za gajenje sorti jabuke duge vegetacije u Srbiji

The favorability for growing apple cultivars with a long vegetation period in Serbia was observed using phenological data form 54 phenological and 24 climatological stations in Serbia in the period from 1961 to 1995. The length of the active period of photosynthesis for the cultivar Jonathan ranges from 169 days in Ivanjica to 211 days in Obrenovac. The average length of this period was strongly correlated with a length of a frost-free period (r = 0.76), while the mean annual air temperature and the mean temperature for the period April-October had a smaller impact on the duration of this period. It was found that the beginning of a growing season was mainly regulated by the temperature after the dormancy was released, while the end and the duration of the growing season were less clearly explained by thermal conditions of a location. The length of the frost-free period may serve as an indicator of favorability of a certain location for the commercial production of apple cultivars with the long growing season in the stated location, although only as necessary but not as sufficient condition. Taking into account the active period of photosynthesis and the length of the frost-free period, four zones of different degrees of favorability for growing apples of the long growing season in Serbia were defined. The most favorable zone encompasses the following regions: Srem, Posavina, Tamnava and lower Podrinje. .U radu su određene zone najmanjeg rizika za gajenje sorti jabuke duge vegetacije na teritoriji Srbije na osnovu srednjeg trajanja fotosinetske aktivnosti listova sorte jonatan i srednje dužine bezmraznog perioda. Za analizu su korišćeni podaci sa 54 fenološke i 24 klimatološke stanice u Srbiji u periodu od 1961. do 1995. godine.