02016naa a2200265 a 450000100080000000500110000800800410001910000190006024500740007926000090015350001080016252012040027065000160147465000100149065000140150065000130151465300250152765300210155265300200157370000150159370000170160870000160162570000130164177300960165420832022017-12-21       2017    bl uuuu     u00u1 u    #d1 aLEOLATO, L. S.  aGrowth regulator and maize response to the increase in plant density.  c2017  aTítulo em português: Regulador de crescimento e resposta do milho ao aumento na densidade de plantas.  aThe objective of this work was to evaluate the effect of application of the growth regulator Trinexapac-ethyl on maize response to the increase in plant density at two sowing dates. A field experiment was carried out in the municipality of Lages, state of Santa Catarina, Brazil, during the 2014/2015 and 2015/2016 growing seasons. Two sowing dates (10/15 ? preferential, and 12/5 ? late), four plant densities (5, 7, 9, and 11 plants m-2), with and without Trinexapac-ethyl application, were tested. The growth regulator was sprayed at a rate of 150 g a.i. ha-1, when hybrid P30F53YH was at the V5 and V10 growth stages. The spraying of Trinexapac-ethyl decreased the stem length above the ear insertion node at both growing seasons. Grain yield ranged from 11,422 to 14,805 kg ha-1, and increased in a quadratic way with the increment in plant density. The highest yields were reached when maize was sown in October. The spraying of Trinexapac-ethyl did not affect grain yield, but decreased the 1,000 kernels mass at both sowing dates. The use of Trinexapac-ethyl does not enhance grain yield of maize hybrid P30F53YH at crowded stands in response to the densification, regardless of sowing time.  aGrain yield  aMilho  aSemeadura  aZea Mays  aRendimento de grãos  aTrinexapac-ethyl  aTrinexapac-etil1 aSANGOI, L.1 aDURLI, M. M.1 aPANISON, F.1 aVOSS, R.  tPesquisa Agropecuária Brasileira, Brasília, DFgv. 52, n, 11, p. 997-1005, novembro 2017.