ABSTRACT
In this chapter, the author summarizes important control points in assimilate partitioning and transport of major crops and describe possible hormonal control within various tissues. A note of caution: Many of the current data provide equivocal evidence that applied hormones or other biochemical regulators may exert significant effects on assimilate partitioning. The definitive role of endogenous hormones as regulators of carbohydrate metabolism, transport, and partitioning remains to be clarified. Regardless of whether a plant is annual or perennial, one of the earliest events affecting productivity is the establishment of the canopy and leaf area. The physical link between the source and sink tissue is provided by the phloem. The rate of translocation along the phloem is believed to be determined by sucrose concentration gradients between source and sink.
