Replacing herbicides with mechanical cultivation can reduce pesticide use in row crop production. Although a majority of Iowa’s corn land is cultivated, most is cultivated only once and herbicide is broadcast applied. To increase grower confidence in reducing herbicide use and in using cultivation for interrow weed control, a three-year field experiment compared various single-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 grain yield were as good or better with the traditional low-crown sweep as with 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 cultivation with a low-crown sweep and a 38-cm (15-in.) wide herbicide band was statistically equivalent to that from a broadcast-only treatment in all three years. Results of this study indicate that herbicide use can be halved and weed control and corn yield can be maintained by use of a 38 cm (15 in.) herbicide band and a single sweep cultivation.
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