Abstract
There are doubts about nitrogen (N) management and the use of growth regulator in wheat. Thus, the objective was to evaluate the wheat performance as a function of topdressing N applied at different phenological stages of crop, and the use of trinexapac-ethyl (TE) growth regulator associated with N fertilization in subtropical regions in southern Brazil. In each environment, two experiments were carried out, all with an experimental design in 2 × 4 factorial scheme. The factors in experiment 1 were topdressing N application at seedling emergence and tillering stages and N rates (0, 40, 80, and 120 kg N ha−1); and in experiment 2: use of TE (with and without) and N rates (0, 40, 80, and 120 kg N ha−1) applied at tillering. The augment of N in topdressing increases the lodging. The use of TE minimizes the lodging. In environment with irrigation, the application of intermediate N rates at crop emergence reduces lodging. The yield components are altered by the rates and stages of N application, with variable responses according to the cultivation environment. The stage of application does not affect grain yield. N fertilization increases the yield, being that in Ponta Grossa the wheat is more responsive to higher N input. In certain environments, TE reduces the number of spikes m−2 and increases the number of grains per spike. TE impairs yield when associated with N non-application in topdressing. On the other hand, it maximizes the effect of N fertilization on yield, when using higher N rates in topdressing.
Disclosure statement
No potential conflict of interest was reported by the author(s).