Morphology and distribution of fully developed root systems of wheat and maize as affected by tillage systems

In fruiting plants there is competition between sinks for photosynthates, ions and hormones. It is affected by sink size, sink activity and progress of senescence of individual organs, and modified by environmental factors. Therefore, fruit-root interaction with respect to partitioning of substances consists of a syndrome of effects, regulated by hormones. Generative organs tend to become dominant sinks exerting strong ‘priority demand’ both for photosynthates and ions. Developing fruits also monopolize hormones (Herzog, 1986), including cytokinins, major endogenous senescence retardants, creating even in some cases deficiency in the leaves (Nooden, 1985). Removal of fruits of grape vines leads to a drastically enhanced cytokinin content in the leaves retarding their senescence (Hoad et al., 1977). Partial defoliation of tomato plants greatly increases the zeatin content of the fruits and even more in the seeds (Monseline et al., 1978; Varga and Bruinsma, 1976).

Z. Starck

Papers

Competition for nutrients between fruits and roots of tomato