Impact of Agronomic Management of Overaged Rice Seedlings on Growth Parameters in North Coastal Andhra Pradesh, India

Abstract

Rice is cultivated in more countries than any other grain crop and belongs to the subfamily Oryzoideae of the Poaceae family. It is the most nutrient-dense grain after wheat, and epidemiological studies have shown that consuming whole grains can reduce the risk of metabolic disorders. A field experiment was carried out on sandy loam soil at the Agricultural College farm in Naira, Srikakulam. The aim was to evaluate the yield attributes and nutrient uptake of various rice varieties influenced by different agronomic management techniques under late-sown and over-aged seedling conditions. The experiment used a split-plot design with three rice varieties: MTU 1210 (M1), MTU 1224 (M2), and BPT 2411 (M3), transplanted at 45 days old as the main plot treatments. The subplot treatments included seven agronomic techniques Planting 33 hills per m² with 6 seedlings per hill + 100% RDN (120 kg N in 2 splits, 70:30) (S1), Planting 44 hills per m² with 3 seedlings per hill + 100% RDN (S2), Planting 44 hills per m² with 6 seedlings per hill + 100% RDN (S3), Planting 33 hills per m² with 6 seedlings per hill + 125% RDN (150 kg N in 2 splits, 70:30) (S4), Planting 44 hills per m² with 3 seedlings per hill + 125% RDN (S5), Planting 44 hills per m² with 6 seedlings per hill + 125% RDN (S6), Planting 33 hills per m² with 3 seedlings per hill + 100% RDN (S7). Results indicated that higher plant densities and increased nitrogen levels significantly improved both growth and yield. Additionally, the interaction effect between rice varieties and agronomic management techniques on days to 50% flowering and days to maturity was not statistically significant. This suggests that the combined effects of different varieties and agronomic practices did not result in notable differences in the timing of these growth stages. The optimal results were observed with the treatment of 44 hills per m², 6 seedlings per hill, and 125% recommended nitrogen dose (RDN). These findings offer valuable insights for enhancing rice cultivation practices using over-aged seedlings, leading to higher productivity and better resource use efficiency in similar agro-climatic regions.