Field studies were conducted in 2007 and 2008 near Lubbock and Lamesa, TX, to determine the effects of propazine alone and in combination with glyphosate applied PRE and POST on cotton growth, yield, and lint value (fiber quality). Propazine at 0.56, 0.84, and 1.12 kg ai ha⁻¹ and in combination with glyphosate at 0.86 kg ae ha⁻¹ was applied PRE, early POST, and mid-POST. Up to 11% injury was observed after propazine applied early POST and mid-POST at Lubbock in 1 of 2 yr, and up to 13% at all three application timings was observed at Lamesa in 1 of 2 yr. The greatest injury was observed 58 d after application following propazine at 1.12 kg ai ha⁻¹ applied PRE; however, no injury was apparent 80 d after application. Cotton yield, lint values, and gross revenues were not affected by any treatment.

Nomenclature: Glyphosate; propazine; cotton, Gossypium hirsutum ‘FiberMax 9058 F’, ‘Americot 1532 B2RF’