Effects of pre-harvest application with natural and synthetic sprout inhibitors on yield and storage quality of potato (Solanum tuberosum L.)

This study was carried out in 2018-2019 to determine the effects of pre-harvest applications of natural and synthetic sprout inhibitors on tuber yield (cv. Alegria and Desiree), dormancy period and some quality characteristics of tubers. Different doses of dill (Anethum graveolens L.), cumin (Carum carvi L.), clove (Syzygium aromaticum L.) and spearmint (Mentha spicata L.) essential oils and chlorpropham (CIPC) and maleic hydrazide (MH) were applied to the plant leaves at 30 days before harvest. Harvested tubers (80-120 g) were stored for 5 months under controlled conditions. Dormancy period, sprout length, weight loss, starch content, reducing sugar content, total soluble solids, tuber hardness, french fries yield and color (L * a *, b *) parameters were examined. Vegetation periods varied between 108-131 days in Alegria, 132-157 days in Desiree, and total tuber yields varied between 2432-4240 kg/da in Alegria and 1980-4249 kg/da in Desiree. The longest dormancy periods in both varieties were determined in MH and 1000 ppm clove and 2500 ppm dill essential oil applications. Weight losses ranged between 5.32-6.53% at the end of the storage period. While the sprout length, french fries yield and starch content increased during the storage period, the reducing sugar contents, hardness and french fries color values of varied but generally decreased. It was concluded that dill and clove essential oils, which prolong the dormancy period of the tubers, can be used as an alternative to synthetic inhibitors, however, these essential oils should be tried at different periods and doses.