A morphological and phenological comparison of chestnut (Castanea) cultivars 'Serdar' and 'Marigoule'

Abstract

Morphological and phenological characteristics of the chestnut (Castanea sativa Mill.) cultivar (cv) 'Serdar' were examined and compared to the cv 'Marigoule', a European x Japanese (C. sativa x C. crenata) hybrid. Morphological characteristics such as tree vigor and growth habit, shoot, leaf, flower, bur and fruit characteristics and phenological characteristics such as time of bud break, flowering, nut ripening and leaf fall were studied. Three trees per genotype and 10-50 samples per tree were examined for each quantitative characteristic. Cultivar 'Serdar' was represented by vigorous trees with semi-upright growth similar to cv 'Marigoule'. Shoots of 'Serdar' were thinner and the shoot bark was browner than 'Marigoule'. 'Serdar' had a higher lenticel density than 'Marigoule' and 'Serdar' had relatively short internodes similar to 'Marigoule'. 'Serdar' initiated break bud 11 days later than 'Marigoule', bloomed 1-2 days later than 'Marigoule', and nuts ripened 20 days later than nuts from 'Marigoule'. Leaf fall of cv 'Serdar' was one day earlier than cv 'Marigoule'. The lamina, petioles and leaves of the 'Serdar' were longer than those of 'Marigoule'; however, 'Serdar' had a lower ratio of lamina width/lamina length and lamina width/leaf length. 'Serdar' and 'Marigoule' were placed in the same group with respect to all flower characteristics investigated. 'Serdar' had globular burs with long spines. Its density of spine was also higher than 'Marigoule'. 'Serdar' had very bright, reddish brown coloured shells, with light cream coloured kernels; and, the fruit had good flavor. Peeling of the seed coat of 'Serdar' was easier than that of 'Marigoule'. The fruit of 'Serdar' was smaller than those of 'Marigoule' and the relative size of the hilum in relation to the upper part of fruit was intermediate in 'Serdar' and large in 'Marigoule'. 'Serdar' showed a higher propensity for splitting of the pericarp although both cultivars were placed within the same group. The cv 'Serdar' can be recommended for new chestnut orchards due to some of its positive advantages such as earlier bearing, blooming twice in a single growing season, resistance to spring frosts and its low susceptibility to chestnut blight.