Biomass production and wheat grain yield and its relationship with NDVI as a function of nitrogen availability

Evaluate the ideal doses of nitrogen fertilizer on wheat crops, in addition to avoiding unnecessary costs, assists in sustainability of the production system. The objective was to evaluate the effect of nitrogen (N) doses on the biomass and grain productivity, and the correlation between the normalized difference vegetation index (NDVI), biomass at flowering and grain yield, in wheat crop. The experiment was carried out in the experimental area of UFRGS, in Eldorado do Sul, in 2017 and 2018, under randomized block, with four replications. The treatments consisted of N doses at sowing (0, 15, 30 e 45 kg de N ha(-1)) and in topdressing (2017 - 0, 20, 40, 60 e 80 kg de N ha(-1) and 2018 - 0, 40 e 80 kg de N ha(-1)). The wheat cultivars BRS Parrudo and TBIO Toruk were used. The treatment with 30 and 45 kg de N ha(-1) applied at sowing combined with 80 kg de N ha(-1) applied in topdressing, were those that obtained the highest yields of both grain and biomass, for both years and cultivars. The correlation between NDVI and biomass and grain yields were high for both years and cultivars.