Apical Dominance in the 'Rogue' Tomato

The rogue tomato exhibits less apical dominance than the normalplant though the degree of correlative inhibition varies considerablybetween winter- and summer-sown plants. An examination of thelevel of endogenous hormones in both rogue and normal plantsat both times of year indicates that the degree of branchingis strongly associated with the levels of auxin in the tissue.It is suggested that this hormone has an effect on apical dominanceby virtue of its role in hormone-directed transport and by itseffect on the formation of abscisic acid in the region of thelateral buds. The results are discussed in relation to currenthypotheses of the mechanism of apical dominance.