Chilling Requirements of Cherries Grown Under Subtropical Conditions of Adana

Abstract

3 Abstract: The chilling requirements of different cherry cultivars and the chilling durations of two different cherry growing areas (Pozanti at 1100 m and Adana at 50 m elevations) were investigated. Results depicted that Lapins and Larian gave the lowest (400-450 hours and 94 chill units) chilling requirement. They were followed by Nafrina with 500-550 hours and 120 chill units. Kordia found to be the highest chilling requiring cherry cultivar (700-750 hours and 150 chill units). While, the others were moderate in chilling response. Calculating total growing degree hours, the highest chilling requiring cherry cultivar Kordia needed the least GDH values (14.000 GDH), the others were around 14.00-16.000 GDH. Calculating the hours below 45°F, Pozant (1100 m elevation) gave 3 or 4 times higher chilling accumulation comparing subtropical conditions of Adana (50 m elevation). However, the chill unit values of Adana and Pozanti were quite similar to each other according to the Richardson's chill units (except 2001-2002-winter period). In comparison of cherry cultivars for dormancy breaking initiation of the buds, Kordia, Larian, Nafrina and Sunburst showed an apical dominancy effect and this effect was the strongest in Sunburst whereas the lightest in Summit. Top cut cuttings of these four cherry cultivars broke dormancy earlier in lateral buds than apical buds. Bud breaks rates of apical and lateral buds in Lapins, Summit and 0900 Ziraat were quite similar to each other.