Effect of mode of application of some growth regulators on the physiology of tomato plants: IV-effect of nicotinamide on the endogenous hormonal contents

ABSTRACT

Application of 10, 40 and 80 ppm nicotinamide either to culture media or used as foliar spray of tomato plants caused stimulatory effects on growth, development, differentiation and fruiting of plants in the order 80 > 40 > 10 ppm, as already mentioned in paper 3 offered simultaneously by the same authors to the same journal. This was accompanied with regular increases in the contents and levels of auxins, gibberellins and cytokinins leading to hormonal balance. However, the IAA oxidase activity was progressively reduced by the increase in the concentration of nicotinamide used. These results safely coordinate with the previously mentioned results in the third paper of this series