Abstract
Postharvest losses are a major impediment to long-term storage of potato tubers. Because of the high costs and lack of infrastructure associated with cold storage, as well as the impracticality of the same during potato transportation, this storage method is often not the most viable option; thus, sprout suppressants are an appealing option that potato producers widely use. The non-renewal of chlorpropham (CIPC), a common sprout suppressant for potato preservation, came into effect in January 2020 within the European Union. This ban on CIPC use, mainly due to toxicity to humans and environmental impact concerns, necessitated the search for novel and natural antisprouting agents. This study aimed to provide a scientific basis for developing postharvest storage and treatment regimes for using sprout suppressants to improve the shelf-life of popular South African potato cultivars, i.e., Mondial, Electra and Panamera, for the export market. The efficacies of selected sprout suppressants in extending the shelf-life of the selected cultivars stored for up to 10 or 12 weeks at ambient temperature (24 ± 1 ℃) were evaluated and compared to untreated controls. The selected anti-sprouting molecules included 1,4-dimethylnaphthalene (1,4-DMN), 3-decen-2-one (SmartBlock), Aloe vera gel 25%, S-carvone and caraway essential oil. Cultivars were separately exposed to 30 μL/Kg S-carvone, 60 μL/Kg caraway essential oil, 98.4 μL/Kg 1,4-dimethylnaphthalene, 25% Aloe vera gel, and 100 μL/Kg SmartBlock. The efficacy of sprout suppressants was monitored by assessing shelflife, the number and length of sprouts, the thickness of sprouts, weight loss, tuber dry matter, firmness and anatomical changes. Also, the effects of three different application techniques (filter paper, fogging, and spraying) on the efficacies of caraway essential oil and SmartBlock in the suppression of potato sprout development were studied. In both cultivars, caraway essential oil delayed sprouting by 21 days after sprouting was observed in the control and reduced number of sprouts (about 2 sprouts per tuber against up to 7 in the control tubers. SmartBlock extended shelf-life for 84 days. For the entire storage period, sprouting did not occur. Sprouting and storage performance was found to be cultivar-dependent...
M.Sc. (Botany)