It depends on the ability of an implement to kill surface weeds without mortally disturbing the germinating crop. For preemergent treatments to be effective, the crop must be planted deeper than the working depth of the broadcast tillage tool. Postemergence, the crop must be more firmly rooted than competing weeds to survive the weeding pass. Years of crusted spring soils boost rotary hoe sales. In these times, the tool s flicking and shattering of soil particles to kill weeds takes second place to its ability to aerate a rain-packed soil surface.
Extra weight helps crust penetration but makes gauge wheels a necessity.
A pair of these supporting tires, one under either side of the rotary hoe toolbar, maintains even penetration by the hoe points. On rough fields, the tires prevent gouging by the hoe wheels on one end of the toolbar. Rotary hoes are not good weeders in tilthy, soft soils. In these conditions, the dragging action of soil-stirring harrows and tine weeders tend to be more effective. The rotary hoe is an effective and efficient tool within a sharply limited window of weed size.