Singh, V. - Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan, Israel

Gamrasni, D. - MIGAL – Galilee Institute of Science, Kiryat Shmoneh, Israel; Tel Hai Academic College, Tel Hai, Israel

Parimi, P. - Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan, Israel

Kochanek, B. - Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan, Israel

Naschitz, S. - MIGAL – Galilee Institute of Science, Kiryat Shmoneh, Israel

Zemach, H. - Department of Fruit Tree Science, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan, Israel

Friedman, H. - Department of Postharvest Science of Fresh Produce, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan, Israel

Lenticel breakdown (LB) mainly occurs in susceptible ‘Gala’ and ‘Red Delicious’ apples following storage. Postharvest calcium treatment increased LB of both cultiavrs as well as the less susceptible ‘Orleans’ and ‘Granny Smith’. Calcium increased the number and size of damaged lenticels. Callose was deposited in the sub-lenticular cells and the cuticle of the damaged lenticels, as well as in non- damaged lenticels. Suberin was deposited in the sub-lenticular cells, but only in the most severely damaged lenticels, and especially in calcium-treated fruit. Postharvest calcium treatment increased the micro- cracking of the skin surface and removed the epicuticullar wax following storage. It also decreased the thickness of the cutin and wax layers. Gene expression, mainly of those involved in the wax biosynthesis and cutin and wax transport, were reduced in peel of calcium-treated fruit. Our study suggests that the deleterious effect of calcium on fruit skin occurs due to a decrease in cuticle deposition during storage, resulting in a thinner cuticle, leading to micro-cracks, which culminates in increased lenticel damage.