Co-Authors:
Teper-Bamnolker, P., Department of Postharvest Science, The Volcani Center, 50250 Bet Dagan, Israel
Dudai, N., Newe Ya'ar Research Center, Agricultural Research Organization, 30095 Ramat Yishai, Israel
Fischer, R., Newe Ya'ar Research Center, Agricultural Research Organization, 30095 Ramat Yishai, Israel
Belausov, E., Department of Ornamental Horticulture, The Volcani Center, 50250 Bet Dagan, Israel
Zemach, H., Department of Fruit Tree Sciences, The Volcani Center, 50250 Bet Dagan, Israel
Shoseyov, O., The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
Eshel, D., Department of Postharvest Science, The Volcani Center, 50250 Bet Dagan, Israel
Abstract:
Sprouting of potatoes during storage, due to tuber dormancy release, is associated with weight loss and softening. Sprout-preventing chemicals, such as chlorpropham (CIPC), can negatively impact the environment and human health. Monthly thermal fogging with mint (Mentha spicata L.) essential oil (MEO) inhibited sprouting in eight potato cultivars during large-volume 6-month storage: the tubers remained firm with 38% lower weight loss after 140 days of storage. The sprout-inhibitory action may be nullified: treated tubers washed with water resumed sprouting within days, with reduced apical dominance. MEO application caused local necrosis of the bud meristem, and a few weeks later, axillary bud (AX) growth was induced in the same sprouting eye. MEO components analysis showed that 73% of its content is the monoterpene R-carvone. Tubers treated with synthetic R-carvone in equivalent dose, 4.5 μl l-1, showed an inhibitory effect similar to that of MEO. Surprisingly, 0.5 μl l-1 of MEO or synthetic R-carvone catalyzed AX sprouting in the tuber. To the best of our knowledge, this is the first report of an essential oil vapor inducing early sprouting of potato tubers. R-carvone caused visible damage to the meristem membrane at sprout-inhibiting, but not sprout-inducing doses, suggesting different underlying mechanisms. After 5 days' exposure to R-carvone, its derivatives transcarveol and neo-dihydrocarveol were found in buds of tubers treated with the inhibitory dose, suggesting biodegradation. These experiments demonstrate the potential of MEO vapor as an environmentally friendly alternative to CIPC in stored potatoes and as a research tool for the control of sprouting in plants. © 2010 Springer-Verlag.