Effect of mode application of some growth regulators on the physiology of tomato plants I effect of indole-acetic acid [IAA] on morphology, growth, metabolism and productivity

In the present study spraying the vegetative parts of tomato plants or root exposure to the different concentration of IAA [10, 20, 40, 80 ppm] gave evidence that IAA can be absorbed and translocated from the rooting media to the shoots and vice-versa. The length of the main stem of treated plants was maximum when 80 ppm IAA concentration was used accompanied by minimum lengths of the corresponding main roots. The changes in total carbohydrates was mainly in polysaccharide fractions, while those of the total nitrogen were mainly in proteins and nucleic acids mainly RNA, 10 ppm concentration was the most promotive but 80 ppm was the least promotive. IAA activated the intake of some mineral elements studied; the maximum increase was shown by 10 ppm which then decreases by the increase of IAA concentrations. IAA induced flower and fruit giving in number and weight and the greatest induction was noticed with 10 ppm concentration whether the plants were sprayed once or twice

Effect of mode of application of some growth regulators on the physiology of tomato plants: I effect of IAA on the endogenous hormonal contents

Application of 10 ppm IAA concentrations to the culture media or used as foliar spray of tomato plants caused stimulatory effects on growth, differentiation, development and fruiting of plants. 40 ppm concentration however, caused less activation than that exerted by 10 ppm concentration. This was accompanied with regular increases in the contents and levels of auxins, gibberellins and cytokinins leading to hormonal balance. The high concentration of IAA [80 ppm] however induced inhibiting effect on the previously mentioned phenomena which were accompanied with increases in the level and activity of endogenous inhibitors mainly unsaturated lactones and also with low levels of auxins, gibberellins and cytokinins leading to hormonal imbalance. Also the IAA oxidase activity was enhanced by the application of higher concentration of IAA. These results can easily interpret the previously mentioned results in the first paper of this series

Effect of mode of application of some growth regulators on the physiology of tomato plants III effect of nicotinamide on morphology, growth, metabolism and productivity

The present results showed evidence that nicotinamide is absorbed and translocated from the roots to the shoots and vice-versa. The length of the main stem and root as well as their lateral branches was increased by the increase of nicotinamide concentrations applied. This led to parallel increases in fresh and dry weights of the plant organs. The apical dominance of plants sprayed with 80 ppm nicotinamide was less than that of those sprayed with 10 ppm concentration. However, plants sprayed twice were more responsive than those sprayed once. Carbohydrates mainly polysaccharides, nitrogenous compounds mainly proteins, nucleic acids and uptake of some mineral elements-were increased by the increase of nicotinamide concentrations applied. Nicotinamide induces flowering and fruit growth in number and weight of fruits consequent to spraying mainly with 80 ppm concentrations

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

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