Effect of different doses of gibberellic acid GA3 on growth, yield and seed production in rice (Oryza sativa L.)

The present study was conducted in field Experimentation Centre and Seed Testing Laboratory of Department of Genetics and Plant Breeding, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (Uttar Pradesh) during Kharif 2023-2024.

The soil of experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 7.1), low in organic carbon (0.36 %), available N (171.48 kg/ha), available P (15.2 kg/ha) and available K (232.5 kg/ha). The experiment was laid out in randomized block design with eight treatments including control which were replicated thrice.

The results revealed that plant height (213.53 cm), days to 50% flowering (93.67 DAS), days to maturity (123.67 DAS), flag leaf length (37.83 cm), flag leaf width (top) (0.56 cm), flag leaf width (middle) (1.04 cm), flag leaf width (bottom) (1.02 cm), number of tillers (22.63), total productive tillers (18.29), panicle length (32.76 cm), seed yield per plot (35.84 g), test weight (25.87 g), spikelets per panicle (81.43), biological yield (142.84 g) were recorded significantly higher in treatment (T5) followed by T4. The study conducted in seed testing laboratory revealed that germination percent (93.67%), root length (13.84 cm), shoot length (13.67 cm), seedling length (27.51 cm), seedling fresh weight (1.15 g), seedling dry weight (0.28 g), seedling vigor index I (2576.88), seedling vigor index II (25.75) were observed significantly higher in treatment (T5) followed by T4. It was concluded from the study that treatment T5- gibberellic acid (125 PPM) recorded significantly higher physiological, yield parameters and biochemical parameters.