Resource re‐allocation following fruit removal in cucurbits: patterns in cantaloupe melons

Abstract

SUMMARYThe effects of removal of fruits of marketable size on investment to male, female and vegetative activities., were evaluated using cantaloupe melons, Cucumis melo L., cv. Retata Degli Ortolani. Leaf and flower demography were used to examine the dynamics of potential trade‐offs among these activities. Treated plants and controls had similar total biomass, but it was distributed differently. Treated plants had more vegetative biomass, both above ground and in roots, whereas control plants allocated more, in both absolute and proportionate terms, to fruits. Treated plants produced more leaves than controls, but individual leaf life expectancies were the same. Developing fruits on control plants thus seem to act as sinks at the expense of new leaves. Fruit removal also significantly stimulated production of male flowers and fruit, though these fruits contained significantly fewer, and smaller, seeds. Once fruit removal had begun, lability of floral sex expression was evident. In treated plants there was a significant increase in the production of male flowers. Both treated and control plants produced the same number of pistillate flowers; adjustments of fruit production occurred because of differences in the rate of successful fertilization, and later, differences in fruit set. In control plants (but not in treated plants) there were obvious tradeoffs between yield components. The costs of fruit maturation in treated plants appeared to be decoupled from other yield components.