A compact incorporator-planter, which incorporates herbicides into moist soil simultaneously with planting of cotton (Gossypium hirsutum L.), was constructed and evaluated over 3 yr using six herbicides. Weed control was consistent with that reported for large, cumbersome units utilizing standard planters and incorporating units from ground-driven rotary tillers and was enhanced in seasons in which rain fell during the first 3 weeks after planting. Among the dinitroaniline herbicides, dinitramine (N4,N4-diethyl-α,α,α-trifluoro-3,5-dinitrotoluene-2,4-diamine) controlled barnyardgrass [Echinochloa crus-galli (L.) Beauv.], and redroot pigweed (Amaranthus retroflexus L.) most effectively. Cotton stands and yields were equivalent to those obtained using standard cotton-planting methods.

Combinations of rotary hoeing, cultivation, and band- or broadcast-applied herbicides were compared for weed management in corn at 64 locations in Iowa from 1987 to 1991. Cultivation alone resulted in denser weed populations than herbicide treatments at 41% of the locations; however, corn yields were reduced at only 22% of the locations when weeds were controlled mechanically rather than with herbicides. Compared with broadcast applications, herbicides applied in a band resulted in increased weed populations at 8% of the locations; however, corn yields were reduced at only 1% of the locations.

Most farmers now rely on herbicides and, to a lesser extent, cultivation to control weeds in Glycine max in the Midwest. However, the general public is concerned that widely used herbicides will contaminate surface and groundwater. Alternative ways to control weeds in field crops are needed to reduce or prevent herbicide contamination of surface and groundwater. A new between-row-mowing weed management system that consists of band-applied herbicides over crop rows + two or more between-row mowings was tested in G. max over 6 yr in Missouri. Mowing weeds close to the soil surface two or more times between crop rows killed or suppressed annual grass and broadleaf weeds, chiefly Setaria faberi, Ambrosia artemisiifolia, and Amaranthus spp., if properly timed. Shading by crop canopy closure contributed to weed suppression in this weed management system. G. max yield also could not be distinguished from weed-free check plots and was greater than the weedy check plots. Herbicide use was reduced 50% by banding because only 50% of the field area was sprayed. The between-row-mowing weed management system may have use in environmentally sensitive areas to help reduce soil erosion or water contamination by herbicides.

Reduced-rate zone herbicide application (ZHA) consists of banding reduced herbicide rates between crop rows (≤ full broadcast registered rate, 1×) and banding much reduced herbicide rates over crop rows (≪ 1×). The objective of this research was to compare the mechanically complicated dual-boom ZHA sprayer with a much simpler, single-boom ZHA sprayer for controlling giant foxtail and common waterhemp in field corn in 2003 and 2004 in Missouri. The dual-boom ZHA sprayer employed two different herbicide solutions, which were propelled through two booms on separate sprayer systems to apply different herbicide rates over in-row and between-row areas while maintaining similar carrier volumes and coverage through two booms. In contrast, the single-boom ZHA sprayer is a mechanically simpler system in which both herbicide rates and carrier volumes were varied across one boom over in-row (IR) and between-row (BR) areas. In single-boom ZHA, two different nozzle tips were alternated on one boom over in-row and between-row areas, the number of nozzles per boom was doubled, and the distance between nozzles was halved compared with a conventional sprayer boom. In a 2-yr study, these different ZHA sprayers were used to apply preemergence atrazine + S-metolachlor between and over crop rows at various reduced rates (1× = 2,240 + 1,750 g ai/ha, respectively). Among all single- and dual-boom ZHA sprayer treatments and the weed-free checks, corn yields and in-row total weed cover were statistically indistinguishable for both years and for between-row total weed cover in 1 of 2 yr. In both years, a single-boom ZHA system prevented yield loss from competing weeds as effectively as the dual-boom ZHA system. The new single-boom ZHA system is a mechanically simple, inexpensive, generic alternative for reducing herbicide rates and lowering input costs.

In previous research, summer annual weeds were successfully controlled in no-till corn with between-row mowing systems that consisted of soil-residual preemergence herbicides banded over corn rows followed by mowing weeds close to the soil surface one or two times later during the growing season. The objective of this research was to determine whether between-row mowing systems could successfully control both winter annual and summer annual weeds as well as broadcast herbicides perform in no-till corn. In two of three years in Missouri, between-row mowing systems controlled and reduced both winter annual and summer annual weed cover and prevented weeds from reducing corn yields. Corn yields for the following no-till weed management systems equaled the weed-free check: winter annual weed control with between-row mowing plus preplant, banded, postemergence-applied glyphosate at 1.1 kg ae/ha and later summer annual weed control with postplant, banded, preemergence-applied atrazine plus S-metolachlor at 2.2 plus 1.8 kg ai/ha followed by between-row mowing. Winter annual weeds growing between rows were controlled with one mowing, and later summer annual weeds were controlled with either one late or “middle” mowing or two mowings (i.e., early and late). Total herbicide use was reduced 50% (i.e., 25 and 25%, respectively) in no-till corn. Commercially acceptable corn stands were needed for between-row mowing systems to adequately control weeds. In one of three years when corn stands were half of those of the other two years, broadcast herbicides performed better than between-row mowing systems in no-till corn.

Alternative methods are needed to control weeds in no-till corn and soybean which minimize herbicide contamination of surface or ground water. The objective of this research was to determine whether between-row (BR) mowing + band-applied herbicide could help reduce herbicide use, without sacrificing summer annual weed control or yield, in no-till soybean and field corn. Glyphosate was applied shortly before or at planting to control emerged winter annual weeds in all treatments. In the BR mowing weed management system, the band-applied soil residual herbicides imazaquin + alachlor in soybean or atrazine + alachlor in corn were applied shortly before or after planting followed by two or more between-row mowings to control summer annual weeds. Annual weeds were first mowed when they were about 8 cm tall and again just before crop canopy closure. Between-row mowing weeds very close to the soil surface two or three times killed or suppressed summer annual grass and broadleaf weeds, chiefly giant foxtail, common cocklebur, and horseweed, when timed properly. The BR mowing weed management system increased yield above a weedy check in these no-till crops. It also controlled weeds and yielded as well as or better than broadcast-applied herbicide at the same rates. Use of soil residual herbicides to control summer annual weeds was reduced 50% by banding because only 50% of the field area was sprayed.