Identification of growth‐related indicators affecting the appearance and protein content of rice grains

To facilitate the stable production of rice (Oryza sativa L.) in a changing climate, it is imperative to establish optimal N application rate via growth diagnosis. In this study, field experiments were conducted identify useful indicators white-back grains and protein content rice. During reproductive stages 2018 2019, we applied at different rates recorded soil plant analyzer development (SPAD) readings normalized difference vegetation index (NDVI) measurements. The grain percentage more strongly correlated with SPAD NDVI during stage when 2019 data combined than separate for each year. data, most dominant factor affecting 4–2 wk before heading, whereas was 1 heading. Similarly, factors on all measurement days, one These results suggest that heading are determining reduce occurrence regulate content.