Effect of plant growth regulators on seed germination and seedling characters in terms of root length and shoot length. The seeds of sesame variety TVM -1 were treated with different concentration of gibberlic acid (1.0, 2.0, 3.0 and 4.0 mg/l) and indole acetic acid (1.0, 2.0, 3.0 and 4.0 mg/l). From the results, it was observed that the GA 3 and IAA at 2.0mg/l had regulatory effect on seed germination and seedling characters. Maximum germination, root length and shoot length was observed at 2.0mg/l in GA 3 and 2.0mg/l in IAA than control. And GA 3 at 2.0gm/l was found to be more efficient to modify seed germination and seedling characters when compared to IAA and control.

The experiment was undertaken with an objective to investigate the effect of various concentrations of plant growth regulators, i.e., Gibberellic acid (GA 3 ) and Indole 3-acetic acid (IAA) on seed germination of Macrotyloma uniflorum. Seeds were soaked for 12 hours in different concentrations substances (1.0, 2.0, 3.0 and 4.0 mg/L) of IAA, GA 3 and control set was soaked only in distilled water. Three replicates of each treatment with fifty seeds per replicate were arranged for precise physiological analysis. Significant variation was found in all aspects after analysis of variance (ANOVA) of each mean value. After two weeks of seed soaking, it was noted that germination percentages were significantly accelerated by lower concentrations (1 and 2 mg) of used hormones. Amongst the two potential growth regulators, 2 mg/L was found most effective because it showed highest germination percentage for IAA (93%) and GA 3 (88%). A great deal of information relating to seed germination practices shows that these plant growth regulators were efficient in overcoming dormancy leading to rapid seed germination. IAA was selected as best hormone in this study, which showed highest seed germination (93%).

The influence of hormones viz. Indole acetic acid (IAA), Gibberellic acid (GA3), Cytokinins viz. Benzyladenine (BA), Benzimidazole (BZI), biocides viz. 2,4-Dichlorophenoxy acetic acid (2,4-D), Diathane M-45, Dimecron and metabolic inhibitors viz. Cycloheximide (CHI) and Actinomycin-D (Act-D) on senescence in detached paddy (Oryza sativa L.) leaves was studied under dark and illuminated conditions. Cytokinins were found to be more effective senescence retardants in light than in dark while auxins were effective in light. Biocides proved to be milder senescence retardants. Effective concentration, a concentration away from the ineffective and toxic range, chosen from IAA, GA3, BA, BZI, 2,4-D, Diathane M-45 and Dimecron were 25,100, 5, 100, 25, 1500 and 0.50 ppm respectively. Application of Act-D (inhibitor of mRNA synthesis) with in 15 min after detachment and cycloheximide (inhibitor of cytoplasmic protein synthesis) from the start of the incubation resulted in suppression of peroxidase activity both under light and dark. Catalase activity exhibited an inverse relation with peroxidase activity under both the experimental conditions. It is recommended that attempts must be made in a more sophisticated way to study the changes in activities of different enzymes suspected to be linked with leaf senescence at a deeper level using all modern techniques available so that the exact nature of enzymes, the isoenzymes pattern and their relation with yield can be understood. Such studies may also help in future in manipulating the projects for the improvement of this economically important cereal crop.

Effect of plant growth regulators on seed germination and seedling characters in terms of root length and shoot length. The seeds of sesame variety TVM – 1 were treated with different concentration of gibberlic acid (1.0, 2.0, 3.0 and 4.0 mg/l) and indole acetic acid (1.0, 2.0, 3.0 and 4.0 mg/l). From the results, it was observed that the GA3 and IAA at 2.0mg/l had regulatory effect on seed germination and seedling characters. Maximum germination, root length and shoot length was observed at 2.0mg/l in GA3 and 2.0mg/l in IAA than control. And GA3 at 2.0gm/l was found to be more efficient to modify seed germination and seedling characters when compared to IAA and control.

In this study, the effect of plant growth regulators (IAA and GA 3 ) and living bacteria containing (Azospirillam) biofertilizer were investigated on the germination, root length and shoot length. The seeds of sesame variety TMV -7 were treated with different concentration of gibberlic acid (1.0mgL -1 , 1.5 mgL -1 , 2.0 mgL -1 and 2.5 mgL -1 ) and indole acetic acid(1.0mgL -1 , 1.5 mgL -1 , 2.0 mgL -1 and 2.5 mgL -1 ). The biofertilizer, Azospirillam was mixed with rice Starch in a container to form slurry. Germination, root length and shoot length were evaluated. From the results, it was observed that the biofertilizer had regulatory effect on seed germination, root length and shoot length over control. In plant growth hormones treated plants, 2.0mg/l of GA 3 shows maximum effect compared to IAA. It can be concluded that, the biofertilizer treatment stimulated the germination and growth by excreting phytohormones and enhancing the nutrient mobilization from the seed.