Effects of Genetic Parthenocarpy and Gynoecious Flowering Habit on Fruit Production and Growth of Cucumber Cucumis sativus L.1

Abstract

Abstract Genetically parthenocarpic cultivars produced significantly less fruit fresh weight when pollinated than without pollination. The development of seed was found to have a dual effect on the development of fruit tissue. In terms of percentage dry weight, seed was produced at the expense of fruit tissue, but from the standpoint of percentage fresh weight, seed development stimulated fruit tissue development. Cucumbers appeared to possess a regulatory mechanism that limits the percentage dry weight that can be devoted to fruit and seed production. Seed dry weight accumulated at the expense of fruit rather than vine dry weight. The presence of fruit was observed to have an inhibitory effect on vine growth that was greater when the fruit contained seed than when it did not. Gynoecious flowering habit, compared to monoecious, did not increase the production of mature fruit. The combination of parthenocarpy, gynoecious flowering, small mature fruit size, and perhaps determinate growth, should help maximize fruit production under a single harvest regime, produce a high fruit to vine ratio, and provide flexibility in harvest timing. The results may apply to other crops where the fruit is harvested in a relatively mature state and where the seed constitutes a substantial proportion of the dry weight.