Effect of gibberellic acid and plant nutrition on the growth and yield of transplanted rice (Oryza sativa L.) in Cauvery Delta Zone

Abstract

The present rate of rice production growth is far below the population growth rate. Therefore, the present deceleration trend in production and yield is a cause of concern and has to be reversed to meet the growing demand. Moreover, the profit margin in rice cultivation has eroded making rice cultivation unattractive. Therefore, new technologies are essential to increasing rice production in the country to meet the future demand of exploding population. Hence, there is an urgent need for enhancement of the productivity of rice by proper agronomic practices. One among them is foliar application of PGRs and NPK fertilizers for exploiting genetic potential of the rice crop. Therefore, a field experiment was conducted during 2022 at the Agronomy Experimental Farm, Faculty of Agriculture, Annamalai University, Tamil Nadu, India to study the effect of plant growth regulators and nutrients on growth and yield of transplanted rice under wetland ecosystem. The rice variety ADT - 43 was used as test variety. The experiment was laid out in randomized block design and replicated thrice with ten treatments includes foliar spray of plant growth regulators (Gibberellic acid, Triacontanol, Sodium para- nitrophenolate) (20 DAT) alone and in combination with macro nutrients like DAP, KCl and NPK (19:19:19) (40 and 50 DAT). The growth, yield parameters, grain and straw yield of rice viz., plant height (101.43 cm), number of tillers/hill (11.85), dry matter production (14847.67 kg/ha), number of panicles/m2 (372.30 m-2) number of filled grains/panicle (125.41), grain yield (6485.25 kg/ha) and straw yield (8890.34 kg/ha) were strikingly impressive by foliar application of gibberellic acid 40 % WSG @ 20 g/ha (20 DAT) along with 2 % DAP + 1 % KCl (40 and 50 DAT). The same trend was followed in harvest index (42.18 %). These combinations showed remarkable promise and seemed to hold greater potential as efficient systems.