Nerson, H., Agricultural Research Organization, Department of Vegetable Crops, Newe Ya'ar Research Center, P.O. Box 1021, Ramat Yishay 30095, Israel

Two field experiments were conducted in Bet Hashita (1992) and Newe Ya'ar (1993), Israel, in order to examine the possibility of using plant growth habit, chlorflurenol, and plant population density to concentrate yield of pickling cucumber (Cucumis sativus L.) under a simulated once-over mechanical harvest system. Two near-isogenic cucumber lines, WI 1983G normal and WI 1983G little leaf, were grown under three plant densities, 5, 10, and 20 plants/m2, and at flowering half of the plants were treated with 50 mg·L-1 chlorflurenol solution. The little leaf line produced a smaller canopy than the normal line under five plants/m2 but a larger canopy under 20 plants/m2. The average commercial yield of the little leaf line was higher than that of the normal leaf line by 28 % and 55% in Bet Hashita and in Newe Ya'ar, respectively. The highest yield of each line was achieved under the highest plant density. The average commercial yields under 20 plants/m2 were 1.13 and 0.91 kg·m-2 in Bet Hashita and 1.86 and 0.92 kg·m-2 in Newe Ya'ar for little leaf and normal leaf, respectively. Chlorflurenol increased fruit number per unit area but did not increase yield. Nevertheless, it increased the proportion of small fruits, which are more valuable. The present study shows that the little leaf growth habit can increase the yield concentration in pickling cucumber and make this crop more suitable for a once-over mechanical harvest. Chemical name used: methyl-2-chloro-9-hydroxyfluorene-9-carboxylate (chlorflurenol).