Growth and Development of Rice as Influenced by Establishment, Residue Retention and Zinc Application

Aims: To investigate the effect of different establishment methods, zinc application and residue retention on the rice plant growth metrics. Study Design: Split-plot design with three replications. Place and Duration of Study: Rice and Wheat Research Centre-CSK HPKV, Malan, Kangra, Himachal Pradesh, India. The study was conducted during Fall of 2021 and 2022. Methodology: We used six main plot treatments viz., M1: transplanting, M2: wet seeding (line sowing under puddle condition), M3: aerobic rice (dry rice cultivation), M4: transplanting + soil application of ZnSO4 (12.5 kg ha-1 + 0.5% ZnSO4 spray) at flowering and early milk stages, M5: wet seeding + soil application of ZnSO4 (12.5 kg ha-1 + 0.5% ZnSO4 spray) at flowering and early milk stages, M6: aerobic rice + soil application of ZnSO4 (12.5 kg ha-1 + 0.5% ZnSO4 spray) at flowering and early milk stages, and three subplot treatments, S1: no residue, S2: 15 cm height of rice straw from ground and incorporation in soil and S3: 30 cm height of rice straw from ground and incorporation. The variety used in the investigation was HPR 1068 of rice. Results: The zinc was treatment resulted in significantly better rice plant height, leaf area index, crop growth rate and net assimilation rate when coupled with transplanting establishment method. Conversely, the aerobic rice establishment without zinc application resulted in significantly (P<0.05) lower rice growth attributes. The days to flowering and physiological maturity were not significantly influenced by the treatments during the study. Conclusion: The transplanting in conjunction with soil application of ZnSO4 12.5 kg ha-1 and foliar application of ZnSO4 0.5% at flowering and early milk stages resulted in significantly higher and better rice plant growth and hence is encouraged.