regulatorsThe experiments were conducted from 2007 to 2009 withthe cultivar Hale, a semi-dwarf genotype selected in West Texas,USA (Brigham, 1970). The planter was adjusted to deliver sixseeds per meter. Treatments consisted of a control and a fac-torial distribution of two PGR applied at three doses and atfive stages of plant development. The PGR were Pix®(mepi-quat chloride—1,1-dimethylpiperidinium chloride) and Stance®(mepiquat chloride + cyclanilide—1-(2,4-dichloroanilinocarbonyl)cyclopropanecarboxylic acid). The doses of both products were0.38, 0.51, and 0.73 L ha−1applied at one time. The doses werein the range of rates commonly recommended for cotton crop.Sprayings were made in the following stages of development: (i)expanding leaf in the 6th node of the primary stem, (ii) expand-ing leaf on the 8th node of the primary stem, (iii) appearance ofthe first inflorescence, (iv) one expanding leaf in a secondary stemafter the appearance of the first inflorescence, and (v) appear-ance of the second inflorescence. The experiment in 2007 didnot include Pix®, and the spraying at the stage of 6th nodein 2009 was not performed because of excessive rains duringthe period