Improvement of grain filling in rice through foliar spray by nutrients and growth promoters
V Ravichandran, K Ragadevi, K Vanitha, M Raju, K KrishnaSurendar, G Senthilkumar
An investigation was carried during 2018 at Department of Rice, Tamil Nadu Agricultural University, Coimbatore. The objective of the experiment was to identify the suitable foliar nutrient/ growth promoter for enhancing grain filling in rice. Three rice genotypes, ADT (R) 49, RICE CO 52 and CO 50 were grown under different foliar treatments. The treatments are 2% DAP+ 1% KCl, 2% MAP+ 1% KCl, ZnSO4 0.5%, 6-Benzylaminopurine 30 ppm, Homobrassinolide 0.3 ppm, NAA100 ppm and 1-MCP 20 ppm and the control plots were sprayed with water. Foliar spray was taken up at two stages, pre-anthesis (just before heading) and post-anthesis (2 weeks after flowering or during grain filling stage). The grain filling characteristics of rice genotypes significantly varied with the different foliar nutrients. The grain filling duration (25.0 days) significantly increases with the treatment 6 - Benzylaminopurine (30 ppm) in the genotype Rice CO 52 and the grain filling rate (1.24 mg grain-1 day-1) was found to be higher in genotype in the genotype CO (R) 50 under the treatment T3 – 2% MAP + 1% KCl. The hormone concentration in grains showed a significant increase with the different foliar application. High ABA and ethylene ratio was observed in the treatments. The treatment 1- MCP (20 ppm) had recorded the high ABA and ethylene ratio in superior grains in the genotype Rice CO 52 (7600.0) and in inferior grains (954.6) followed by the genotype ADT (R) 49 (4250.0 and 833.3) in the superior and inferior grains respectively.The maximum grain yield of 8536.7 kg ha-1 was registered by CO (R) 50 with an increase of 19.2 per cent under the treatment of 1- MCP (20 ppm) over other treatments and genotypes. To conclude, foliar application of 1- MCP (20 ppm) and 6-Benzylaminopurine (30 ppm) at pre-anthesis and post anthesis stage to suppress ethylene production further strengthened the grain sink strength of inferior spikelets at same time development of more number of cells in endosperm by synthetic cytokinin (BAP) thereby registered better grain filling process and yield components in the rice genotype CO (R) 50.
V Ravichandran, K Ragadevi, K Vanitha, M Raju, K KrishnaSurendar, G Senthilkumar. Improvement of grain filling in rice through foliar spray by nutrients and growth promoters. International Journal of Ecology and Environmental Sciences. 2020; 2(4): 599-604.