Effect of Consecutive Annual Applications of Fluometuron on Cotton (Gossypium hirsutum)

Abstract

Cotton [Gossypium hirsutum(L.) ‘Hancock’] lint yield or quality was not adversely affected under weed free conditions by three consecutive annual preemergence applications of up to 1.68 kg/ha fluometuron [1,1-dimethyl-3-(a,a,a-trifluoro-m-tolyl)urea] alone or in combination with 0.84 kg/ha trifluralin (a,a,a-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) preplant incorporated on silt loam soils of the Memphis catena containing less than 1% organic matter. Similar applications of fluometuron at 3.36 kg/ha delayed maturity of cotton plants and ultimately reduced lint yields. Trifluralin treatments tended to overcome the detrimental effects of high rates of fluometuron. There was no effect on fiber development and maturation because fiber length and fineness (micronaire) were virtually identical for all treatments. The effect on maturity as determined by percent first harvest was a reflection of slower plant growth and fruiting and not of the development of the fiber itself. These results indicate no detrimental effects on cotton yield, maturity, and quality from annual applications of these herbicides at rates recommended and normally used in Tennessee.