ABSTRACT
This chapter explores the rate-limiting processes which regulate the partitioning of assimilate for fruit production in tomato. The total dry matter production and partitioning within the plant can differ considerably between these two types of tomato. For example, a determinate tomato plant grown in California, without deleafing, would accumulate 445 g dry matter with a harvest index of 55%. The growth pattern of a tomato plant suggests that there is a definite priority in assimilate partitioning among the growing organs. The subsequent inflorescence development is delayed and the growth of shoot and roots is retarded further, even causing early leaf senescence or root death. The competition between sink organs for assimilate may be facilitated by the common transport path between some sink organs and their common source leaves. Hormonal stimulation of flower development or fruit set can also enhance the import of assimilate for reproductive growth at the expense of vegetative growth.
