Wheat yield potential estimation using active optical sensor for site-specific nitrogen fertilization

Nitrogen fertilization in spring wheat is based on yield potential, soil organic matter content and previous crop. Yield potential definition is difficult, since it is affected by weather conditions. The objective of this research was to evaluate the relationship between normalized difference vegetation index (NDVI) measured by an active sensor and grain yield of four wheat cultivars. The experiment was carried out at field conditions in 2009. NDVI in different growth stages and grain yield were evaluated. NDVI measured was efficient to detect growth variability generated by N availability and correlated well with grain yield for all cultivars tested, indicating that yield potential can be estimated by NDVI evaluations during crop ontogeny. One single model for the relationship between NDVI and yield potential can be used considering cultivars used in this research.