Chen, Y., The Seagram Center for Soil and Water Sciences, The Hebrew University, Faculty of Agriculture, P.O.B. 12, Rehovot, 76100, Israel
Steinitz, B., Division of Ornamentals, Agricultural Research Organization, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Cohen, A., Division of Ornamentals, Agricultural Research Organization, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Elber, Y., Division of Ornamentals, Agricultural Research Organization, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel

Plants of Gladiolus grandiflorus 'Friendship' were grown on a CaCO3-containing soil treated with the following soil-applied Fe fertilizers: (1) self-produced Fe-enriched peat (Bar-Teva 55); (2) Fe-enriched ammonium polyphosphate (APP); (3) FeEDDHA (sequestrene 138). Foliar application of FeSO4 solution in the presence of a wetting-agent (L-77) was also tested. Bar-Teva 55, FeEDDHA and FeSO4+L-77 were found to be effective in the prevention of chlorosis, while APP was not. About 95% of the Bar-Teva 55-treated plants flowered, compared to 79-89% for the other treatments. Flowering in Bar-Teva 55-treated plants started a few days earlier. None of the fertilizers affected inflorescence stem length or the post-harvest keeping-quality of the flowers. With the exception of APP, the fertilizer treatments improved daughter corm growth. The number of cormels per corm in the Bar-Teva 55-treated plants was markedly higher than in other treatments. FeEDDHA and FeSO4+L-77 treatments also increased cormel number per corm when compared to APP-treated plants and control. Effective Fe-containing fertilizers seem to be of great importance to flowering, corm growth and cormel formation. Fe-enriched peat was found to be the most efficient fertilizer among the ones tested. © 1982.