Akademik Veri Yönetim Sistemi
ACTA HORTICULTURAE, cilt.1379, ss.191-198, 2023 (SCI-Expanded)
Harvesting hazelnuts is generally done by hand from the trees in Turkey. Some growers tend to harvest early to avoid labor shortages, to escape from rains, to pick the clusters before falling to the ground on very steep slopes or to return to where they live before school starts. This study was performed to determine the optimal harvest date, and the effects of early and late harvest on the pomological and some chemical properties. The nuts were harvested at one-week intervals from mid-July to the end of August. The color change in the husks, development of shell color specific to cultivar, the nuts becoming loose in their husks, darkening of the basal scar of the nut, and the onset of cluster fall were recorded. The change in husk color was not a reliable indicator for the date of harvest except for ‘Tombul’. In general, nut dimensions (length, width, thickness and size), and shell thickness were stable after mid-July while kernel dimensions, nut and kernel weight, percent kernel and oil content increased but protein content decreased as the harvest date progressed. Picking the nuts before August 6 for ‘Allahverdi’, ‘Okay28’ and ‘Tombul’, and August 13 for ‘Çakıldak’ was considered early harvest where lower in-shell and kernel weight, and smaller kernel size were the main reasons for reduced yield. The most affected quality parameter was pellicle removal; there was little or no blanching of the kernels from the early harvest dates. Negative effects of late harvest were observed in ‘Okay28’, including increased number of split nuts, black-tips and moldy kernels. The frequency of blanks, double kernels, fiber and insect damage were not associated with the harvest date. In general, harvesting at the onset of cluster drop is suggested to reduce yield loss and increase crop quality.