RESEARCH CONCERNING THE INFLUENCE OF CLIMATE ON EVOLUTION OF PHENOLOGICAL STAGES IN SWEET CHERRY TREE

Carrying out the phenological stages of vegetation and fructification in sweet cherry cultivars is determined by the cumulative action of rainfall registered and daily average temperatures exceeding 5 degrees C, value considered as biological limit of this species. Research was conducted during 2011-2014 at six Romanian cultivars 'Cetatuia', 'Catalina', 'Maria', 'Andreias', 'Margonia' and 'George' and three introduced sweet cherry cultivars 'Van' (Canada), 'Bigarreau Burlat' (France) and 'Bigarreau Donissen' (Germany). Were recorded number of days, active thermal balance (degrees C) and rainfall quantity (mm) on periods between phenological stages: from swelling buds to blooming, flowering period, from end of flowering to ripening of fruits and from ripening of fruits to leaves fall. The number of days recorded in periods between phenological stages from swelling buds to start of blooming was between 20-26 days, the active thermal balance ranged between 192 to 269 degrees C and rainfall quantity ranged between 41 mm to 63 mm. In the blossom period number of days ranged between 8-12 days, with the active thermal balance ranged between 97 degrees C to 151 degrees C and rainfall quantity ranged between 6.5mm to 30 mm. The number of days from swelling buds to start of blooming, from the end of blossom to fruit maturity and from ripening of fruits to leaves fall is positive correlated with the active thermal balance. The number of days from swelling buds to start of blooming and from ripening fruit to leaves fall is positive correlated with the rainfall quantity registered.