A Smooth-Cone Spreader for Application of Dry Herbicide Formulations

Abstract

A new machine consisting of a detachable hopper of containerized granules with a preselected circular orifice to regulate flow of granules, and a revolving hollow-cone spreader turned by an electric motor, was tested. Flow of herbicide granules at typical use rates was linearly correlated with orifice diameter. Coefficients of determination for flow rates of alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide], trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine], and norflurazon [4-chloro-5-(methylamino)-2-(3-(trifluoromethyl)phenyl)-3 (2H)-pyridazinone] were 0.96 or greater. Based on patterns of distribution of commercial trifluralin granules parallel and perpendicular to a linear path, the machine could be used to apply herbicide granules in row crops. Control of johnsongrass [Sorghum halepense(L.) Pers. # SORHA] with alachlor plus oryzalin [4-(dipropylamino)-3,5-dinitrobenzenesulfonamide] applied preemergence (pre) as sprays and granules did not differ significantly in soybean [Glycine max(L.) Merr. ‘Forrest′]. Trifluralin granules applied preplant incorporated (ppi) at 1.1 kg ai/ha controlled 80 to 95% of the johnsongrass and doubled soybean yield compared to the cultivated control plot. Norflurazon plus alachlor pre at 1.7 to 2.2 plus 2.2 to 3.0 kg ai/ha controlled annual grasses and prickly sida (Sida spinosaL. # SIDSP) equally with sprays and granules.