Effect of different methods of application of Zn with reduced NPK fertilizer levels on growth, yield and grain quality of transplant rice ( Oryza sativa . L) VAR. AT 362

An experiment was conducted during the 2018/2019 Maha and 2019 Yala seasons at Rice Research Station, Ambalantota, Sri Lanka to investigate the effect of different methods of Zn application on growth, yield and grain quality in different reduced levels of NPK application on rice var. At 362. The trials consisted of 10 treatments which included three levels of NPK (100, 80 and 65% levels from the recommended dose) and three methods of the application of Zn fertilizer viz. broadcasting of 8 kg/ ha ZnSO4 two weeks after transplanting, dipping seedling roots in 1.5% ZnSO4 solution for 20 minutes and foliar spraying of 0.5%, ZnSO4, 2, 4 and 6 weeks after trans-planting. A randomized complete block design was used with four replicates for the experiment. All tested growth, yield and grain quality parameters showed statistically insignificant results indicating that there is no effect of rate and method of Zn application but there is a possibility to reduce the level of NPK application up to 65% with the application of ZnSO4. When considering the labour requirement, materials used and the time spent for treatments, the root dipping at the time of transplanting can be identified as the easiest and cost-effective method for the application of Zn for rice.