Effects of Pinching Treatments at Raising-seedling Period on Seedling and Growth after Planting of Solanum melongena L. in Double Stem Training

Abstract

In order to obtain fundamental knowledge on a new training method for eggplant, we studied the effects of pinching in raising-seedling period on the seedling and growth after planting. As a result, the raising-seedling period was 9-10 days shorter in the true leaf node pinching (hereinafter as T.P.) compared with the cotyledon node pinching (hereinafter as C.P.). The mature seedling rate was 100 % in T.P. as it was in the conventional but was 70-80 % in C.P. compared with the conventional and T.P.. The number of flowering node on main stem and the number of primary lateral shoots in T.P. were comparable to those in the conventional. In addition, dry weight of the lateral shoot, number of fruits on the lateral shoot, number of marketable fruits, and marketable fruits yield were comparable to, or significantly larger in T.P. than in the conventional. Also, in T.P., leaf number to the first flower were significantly smaller than conventional. From these results, pinching in the raising-seedling period of the eggplant is recommended to be performed in the true leaf node, by which stabilization of the growth of the axillary bud that becomes the main stem and shortening of the raising-seedling period can be expected. Pinching also found to lower the fruit-setting nodes and initial yield was comparable to, or larger than the conventional.