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

ABSTRACT

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