Nir, G., Department of Olei- and Viticulture, ARO, The Volcani Center, Bet Dagan, Israel
Shulman, Y., Department of Olei- and Viticulture, ARO, The Volcani Center, Bet Dagan, Israel
Lavee, S., Department of Olei- and Viticulture, ARO, The Volcani Center, Bet Dagan, Israel

Growth of grapevine and olive shoots was inhibited by dikegulac-sodium (sodium 2,3;4,6-di-o-isopropylidene-2-Keto-L-gulonate). Concentrations of 500-6000 mg l-1 were effective in grapevine 'Perlette', while only 3000 or 6000 mg l-1 inhibited the growth of 'Manzanillo' olive shoots. Dikegulac inhibited growth of grapevine shoot apices, but induced the outgrowth of many lateral buds. It reduced the size of young leaves and clusters; mature leaves, however, were not affected. Application to dormant grapevine buds caused delayed bud opening, weak growth and deformed shoots. Dikegulac reduced the size of young 'Manzanillo' olive trees. At 3000 mg l-1, growth of olive shoot apices was inhibited and numerous laterals grew out below the treated area. At 6000 mg l-1, shoot apices abscised and many small laterals developed from each node. Both concentrations caused swelling of nodes on olive shoots. The possibility of utilizing the material as a growth inhibitor in intensive vineyards and olive orchards was considered. © 1983.