High-speed cultivation and banding for weed management in no-till corn

Replacing herbicides with mechanical cultivation can reduce pesticide use i n row crop production. Although a majority of Iowa's corn land is cultivate d, most is cultivated only once and herbicide is broadcast applied. To incr ease grower confidence in reducing herbicide use and in using cultivation f or interrow weed control, a three-year field experiment compared various si ngle-cultivation plus band-herbicide application strategies with broadcast application strategy and no-control strategy. To cover larger acreages in a narrow window of time, cultivation speed was increased each year from 11.3 to 14.1 to 16.9 km/h (7.0, 8.8, and 10.5 mph). A 38-cm (15-in.) herbicide band treatment had less weed growth, and generally greater yield, extended leaf height, and corn population than did a 19-cm (7.5-in.) band treatment. Few differences were noted among cultivator styles. Weed management and gr ain yield were as good or better with the traditional low-crown sweep as wi th other styles. Its wider cutting width (56-cm or 22 in.) in 76-cm (30-in. ) rows resulted in a lower corn population, however, when operated at 16.9 km/h (10.5 mph) with a crosswind. Differences in weed population and visual weed cover rankings when comparing single-cultivation with broadcast-only strategies varied with years. Grain yield from a treatment using a single c ultivation with a low-crown sweep and a 38-cm (15 in.) herbicide band was s tatistically equivalent to that from a broadcast-only treatment in all thre e years. Results of this study indicate that herbicide use can be halved an d weed control and corn yield can be maintained by use of a 38 cm (15 in.) herbicide band and a single sweep cultivation.