Application of the Nitrogen Nutrition Index to Estimate the Yield of Indica Hybrid Rice Grown from Machine-Transplanted Bowl Seedlings

The purpose was to comprehensively compare the prediction accuracy of different nitrogen nutrition indexes (NNILAI and NNIDM) derived from critical concentration (Nc) models established by leaf area index (LAI) dry matter (DM) in estimating grain yield indica hybrid rice grown machine-transplanted bowl seedlings. Therefore, field experiments were conducted with two high-yielding varieties five application rates 2018 2019. results show that NNIDM peaked stem elongation stage, while NNILAI had its maximal value mid-tillering stage during growth stages. highest correlation relative effective panicle number tillering when compared NNIDM, threshold points NNI 0.971 (active stage) 1.106 (mid-tillering stage). Moreover, seed setting rate elongation–panicle initiation 1.116 (stem 1.053 (panicle In contrast, heading NNILAI, point 1.050 (heading tillering–panicle should be merged effectively improve status evaluation addition This study provides a theoretical basis for improved understanding