Effects of protected cultivation on the earliness, yield and fruit quality characteristics of some peach-nectarine cultivars

This study was carried out to determine the effects of protected cultivation on the earliness, yield and fruit quality characteristics of Astoria and Maya peaches and Garbaja nectarine cultivars. In the study phenological observations such as first flowering, full flowering, end of flowering, harvest dates; yield parameters such as yield per tree, yield per trunk cross sectional area (kg/cm2), yield per acre and fruit quality characteristics such as fruit weight, fruit diameter, fruit height, seed weight, flesh/seed ratio, total soluble solids (TSS), pH and acidity were investigated. In addition, fruit skin and flesh colors (L, a*, b*, C and h°) were measured by Minolta chromometer. In the study, flowering times under protected cultivation ranged between January 31 and February 22, while open flowering ranged between February 15 and March 3 in Antakya/Hatay ecological conditions. The harvest dates of the cultivars under plastic cover were between 29 April and 24 May whereas the harvest dates of the cultivars under open area were between 20 May and 7 June. The fruit ripening of Astoria and Maya cultivars occurred 21 days earlier than the open area and fruit maturation of Garbaja cultivar occurred 10 days earlier than the open area. Astoria cultivar had the highest fruit weight (149.41 g) under plastic cover, while Garbaja and Astoria cultivars had the highest fruit weight (153.70 g and 136.15 g, respectively) under open area. The red color value and its density of the fruit skin under open area was higher than that of plastic cover. The highest yields per tree and per acre were found in Astoria cultivar (21.36 kg/tree and 3545.8 kg/acre, respectively) under plastic cover. In open area, yield parameters were highest in Garbaja (26.58 kg/tree and 4413.7 kg/acre, respectively) and Astoria (25.60 kg/tree and 4296.6 kg/acre, respectively) cultivars. As a result, Astoria cultivar under plastic cover was very promising in terms of earliness, yield and fruit quality characteristics.