Use of growth regulators as priming agent for improvement of seed vigour in tomato (Lycopersicum esculentum)

Seeds of tomato cv. Keabi were primed with of three important growth regulators viz Gibberellic acid (GA3), Napthlene acetic acid (NAA) and potassium nitrate (KNO3). Four concentration of each, Gibberellic acid and Napthlene acitic acid (25ppm, 50ppm, 75ppm.100ppm) and two concentration of KNO3 (1% and 2%) were compared with the distilled water as control. For each treatment seeds were soaked in growth regulator for 24 hrs before put for the germination test. Fifty seeds in four replications were germinated on top of paper at 200C in seed germinator for 14 days. Normally germinated seedlings were counted which gave an estimation of germination percentage. Data was recorded on the germination percentage, shoot length, seed vigour index. Most of the treatments had significant positive effect on all the quality parameters. NAA had showed adverse effect on the root length while other growth regulators were found to be significant role to improve the root length. Maximum seed germination (74%) was observed at 50 and 75ppm GA3. Highest shoot length (4.83cm) was found at 25ppm of GA3 whereas enhancement of root length occurred with the priming of 1% KNO3 (3.52cm ). Seed vigour-I, on the basis of seedling length was observed higher at 25ppm. GA3 (720) and seed vigour –II on the basis of seedling dry weight was also observed maximum priming with 100ppm GA3 (1460). From this study it was suggested that GA3 priming has important growth regulator to enhance the seed germination as well as seed vigour. Before sowing seed should be priming with GA3 for obtaining high % germination and vigorous seedling that survive under adverse condition it also increase the uniformity of field plant stand.