An experiment was conducted at the UEPG "Capão da Onça" School Farm in 1999, Paraná-Brazil, to evaluate the effects of a growth regulator on the wheat cultivar IAPAR-53 grown at different plant populations and nitrogen rates. The experimental design was a randomized complete block in a 2 x 3 x 4 factorial scheme, with four replications. The treatments consisted of applying 125 g a.i. ha-1 of trinexapac-ethyl and control; plant densities of 44, 60 and 75 plants m-1 in a row spacing of 0.17 m and rates of 0, 45, 90, and 135 kg ha-1 of surface broadcast nitrogen. The application of trinexapac-ethyl resulted in less dry matter and short internodes, increased stem diameter, number of spikes m¹, and grain yield. As nitrogen rate increased, so did plant height, number of spikes m-1, grain weight, and grain yield. With the increase of plant density, stem diameter, plant dry weight and the number of grain/spike decreased; however, the number of spikes m-1 and grain weight increased with no detected effect on wheat productivity. No lodging was observed in any of the treatments.
Triticum aestivum; yield; trinexapac-ethyl
