Pomological and phenological characteristics of the main pistachio cultivars in Greece

Abstract
The present study aimed to evaluate the pomological and phenological traits, as well as kernel antioxidant potential of the dominant Greek pistachio cultivars, ‘Aegina’ and ‘Pontikis’ (Pistacia vera L.). Blooming of ‘Aegina’ cultivar occurred from early to mid of April, and nut maturation at middle to late of August. Production started at 6 to 7 years from grafting and full production observed at year 13. Blooming and nut maturation of ‘Pontikis’ occurred about 1 to 2 days later than ‘Aegina’ and production started 6 to 7 years from grafting, with full production observed in the 14th year. Mean tree yields reached 18.0 ± 1.0 kg and 17.4 ± 1.1 kg of dry nuts, in ‘Aegina’ and ‘Pontikis’ cultivar, respectively. ‘Aegina’ cultivar presented intermediate tree vigour and spreading growth habit, whereas ‘Pontikis’ high tree vigour and semi-erect growth habit. ‘Aegina’ nut had a narrowly cordate shape and the percentage of split nut was found at 78.5 ± 6.5. ‘Pontikis’ nut had ovoid shape and the percentage of split nut was 84.1 ± 6.2. In ‘Aegina’ cultivar 100 nuts weighted 101.0 g and in ‘Pontikis’ 114.4 g. Color of kernel was green externally and green to green-white internally, greener in ‘Pontikis’. The antioxidant potential of pistachio kernel measured by FRAP assay, total polyphenolic substances, flavonoids, flavanols and hydroxycinnamic acids content, did not differ (P > 0.05) between cultivars. Evaluation of ‘Aegina’ and ‘Pontikis’ pistachio cultivars revealed that both are high yielding, with large nut sizes of acceptable appearance and high quality.