Herbicide and Cultural Practices in Smutgrass (Sporobolus poiretii) Control

Abstract

Dalapon (2,2-dichloropropionic acid) was applied at 3.3 kg/ha during late May or early June to a well-established grass sward consisting of smutgrass [Sporobolus poiretii (R.&S.) Hitchc], pangolagrass (Digitaria decumbens Stent.), and bahiagrass (Paspalum notatum Flugge. ‘Pensacola’). Two cultural treatments, mowing or roller chopping, and two fertilizer treatments, 0 or N-P-K at 112-25-93 kg/ha were superimposed on the dalapon treatments at four different time intervals in a split plot design. Chopping or mowing 2 weeks after the dalapon treatment resulted in the highest bahiagrass ground cover and smutgrass control with a minimum amount of bare soil. Chopping tended to favor pangolagrass recovery, and mowing favored bahiagrass recovery. Fertilizer application increased pangolagrass ground cover 90-days after treatment, and smutgrass control after 1 yr. Fertilizer application 6 weeks after dalapon treatment generally increased pangolagrass ground cover and smutgrass control. Pangolagrass responded to fertilizer regardless of chopping or mowing. Mowing controlled more smutgrass than did chopping on the non-fertilized plots.