Tolerance of Corn (Zea mays) to Sethoxydim Applied With Precision Postemergence-directed Sprayer Equipment

1989 ◽  
Vol 3 (4) ◽  
pp. 663-667 ◽  
Author(s):  
Craig D. Kleppe ◽  
Robert G. Harvey

The tolerance of 41- and 76-cm tall corn to sethoxydim applied with a precision postemergence-directed sprayer was evaluated in field studies in 1987 and 1988. Corn 41 cm tall at application tolerated directed sethoxydim more than corn 76 cm tall. Sethoxydim plus crop oil concentrate at 110 to 220 g/ha plus 1.3% (v/v) applied to 41-cm corn resulted in little or no injury and no corn grain yield reductions. When sethoxydim at rates exceeding 110 g/ha plus crop oil concentrate was applied to corn 76 cm tall, injury occurred which reduced corn grain yield. Good tolerance of 41-cm tall corn validates the safety and effectiveness of postemergence-directed sethoxydim when applied with precision sprayer equipment.

1997 ◽  
Vol 11 (3) ◽  
pp. 602-607 ◽  
Author(s):  
Eric Spandl ◽  
Thomas L. Rabaey ◽  
James J. Kells ◽  
R. Gordon Harvey

Optimal application timing for dicamba–acetamide tank mixes was examined in field studies conducted in Michigan and Wisconsin from 1993 to 1995. Dicamba was tank mixed with alachlor, metolachlor, or SAN 582H and applied at planting, 7 d after planting, and 14 d after planting. Additional dicamba plus alachlor tank mixes applied at all three timings were followed by nicosulfuron postemergence to determine the effects of noncontrolled grass weeds on corn yield. Delaying application of dicamba–acetamide tank mixes until 14 d after planting often resulted in lower and less consistent giant foxtail control compared with applications at planting or 7 d after planting. Corn grain yield was reduced at one site where giant foxtail control was lower when application was delayed until 14 d after planting. Common lambsquarters control was excellent with 7 or 14 d after planting applications. At one site, common lambsquarters control and corn yield was reduced by application at planting. Dicamba–alachlor tank mixes applied 7 d after planting provided similar weed control or corn yield, while at planting and 14 d after planting applications provided less consistent weed control or corn yield than a sequential alachlor plus dicamba treatment or an atrazine-based program.


Weed Science ◽  
1986 ◽  
Vol 34 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Jon P. Chernicky ◽  
Fred W. Slife

Field studies were conducted to measure the response of corn (Zea maysL. var. ‘Pioneer 3377’) to foliar applications of sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one}, fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy] propanoic acid}, and haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy] propanoic acid} as influenced by corn growth stage and the addition of 7.7, 15,4, 77.7, 140, 280, and 840 g/ai/ha of bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide]. Applications of sethoxydim (16.8, 33.6, 67.2, 100, and 134 g ai/ha), fluazifop, or haloxyfop (1.0, 2.0, 4.0, 8.0, 10.0, and 13.4 g ai/ha) to four- to five-leaf corn did not reduce seed weight, but significant reductions resulted when sethoxydim (100 g/ha) or fluazifop (13.4 g/ha) was applied to 70- to 80-cm (six-leaf) corn with or without bentazon. Corn grain yield was significantly reduced by sethoxydim (>67.2 g/ha) treatment at either growth stage of corn. In contrast, corn injury induced by fluazifop (>8.0 g/ha) and haloxyfop (13.4 g/ha) resulted in reductions in yield only when applications were made to 70- to 80-cm corn. Significant reductions in seed germination also resulted from foliar applications of the graminicides, but these reductions were inconsistent across corn growth stage.


Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 600-603 ◽  
Author(s):  
Jon P. Chernicky ◽  
Roger Gast ◽  
Fred W. Slife

Corn and giant foxtail response to foliar-applied sethoxydim at 67, 134, and 200 g ai/ha was evaluated in field studies. Sethoxydim applied over the top of corn (60 cm tall) caused greater whorl damage and reduced corn grain yield more than postdirected sethoxydim. Sethoxydim controlled giant foxtail best when used in conjunction with a preemergence application of metolachlor (2.2 kg/ha) and atrazine (1.7 kg/ha).


1985 ◽  
Vol 65 (3) ◽  
pp. 481-485 ◽  
Author(s):  
G. J. HOEKSTRA ◽  
L. W. KANNENBERG ◽  
B. R. CHRISTIE

The objective of this study was to determine the effects on grain yield of growing cultivars in mixtures of different proportions. Two maize (Zea mays L.) hybrids, Pride 116 and United 106, were grown for 2 yr in pure stand and in seven mixtures of different proportions (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, 1:7) at plant densities of 61 500, 99 400, and 136 000 plants per hectare. The total number of mixture combinations was 42, i.e. 2 years × three densities × seven proportions. All but one mixture yielded as expected based on the yield of component hybrids in pure stand. The higher yielding hybrid (United 106) yielded significantly less grain per plant in mixtures than in pure stand. The lower yielding hybrid (Pride 116) yielded more in mixtures than in pure stand, although the difference was not significant. These data support previous observations that the ability of a hybrid to yield in pure stands is not necessarily related to its ability to yield in mixtures. High plant densities appear to enhance the likelihood of interactions occurring among hybrids. For United 106, the number of proportions yielding less grain per plant than in pure stand was highly significant at the two higher plant densities. For Pride 116, the number of proportions yielding more than in pure stand was highly significant at the highest plant density.Key words: Corn, grain yield, mixtures of different proportions, high plant densities, Zea mays


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Alexandra M. Knight ◽  
Wesley J. Everman ◽  
David L. Jordan ◽  
Ronnie W. Heiniger ◽  
T. Jot Smyth

Adequate fertility combined with effective weed management is important in maximizing corn (Zea mays L.) grain yield. Corn uptake of nitrogen (N) is dependent upon many factors including weed species and density and the rate and formulation of applied N fertilizer. Understanding interactions among corn, applied N, and weeds is important in developing management strategies. Field studies were conducted in North Carolina to compare corn and weed responses to urea ammonium nitrate (UAN), sulfur-coated urea (SCU), and composted poultry litter (CPL) when a mixture of Palmer amaranth (Amaranthus palmeri S. Wats.) and large crabgrass (Digitaria sanguinalis L.) was removed with herbicides at heights of 8 or 16 cm. These respective removal timings corresponded with 22 and 28 days after corn planting or V2 and V3 stages of growth, respectively. Differences in N content in above-ground biomass of corn were noted early in the season due to weed interference but did not translate into differences in corn grain yield. Interactions of N source and N rate were noted for corn grain yield but these factors did not interact with timing of weed control. These results underscore that timely implementation of control tactics regardless of N fertility management is important to protect corn grain yield.


Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 944-947 ◽  
Author(s):  
Hani Z. Ghosheh ◽  
David L. Holshouser ◽  
James M. Chandler

Experiments were conducted from 1989 to 1991 to determine the critical period of johnsongrass control in field corn. Maximum weed-infested and weed-free periods of 0 to 20 wk after corn emergence were maintained by either hand weeding or nicosulfuron application. Interference duration effects on corn grain yield were not affected by johnsongrass control methods. The critical period for johnsongrass control was determined to be between 3 and 6.5 wk after corn emergence to avoid losses above 5% of yield produced by full-season weed-free corn.


Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 879-883 ◽  
Author(s):  
Hani Z. Ghosheh ◽  
David L. Holshouser ◽  
James M. Chandler

Experiments were conducted from 1990 to 1994 to investigate the density-dependent effects of rhizome and seedling johnsongrass on the magnitude of full-season interference in field corn. Corn grain yield was decreased as rhizome johnsongrass density increased. A maximum density of 3 rhizome johnsongrass plants 9.8 m−1of row was considered critical to avoid yield losses above 5% of full-season weed-free corn. Interference of johnsongrass plants originating from seed and growing at densities up to 128 plants 9.8 m−1of row did not affect grain yield. Seedling johnsongrass plants growing at a constant density of 9.8 plants m−1of row did not affect yield from corn planted at five densities.


Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 903-910
Author(s):  
Gail A. Wicks ◽  
Robert G. Wilson ◽  
Garold W. Mahnken ◽  
Gordon E. Hanson

Field studies were conducted to determine the influence of annual herbicide treatments plus cultivation on weed populations and corn yields in ridge-till corn during a 3-yr period at Mitchell, NE, and a 7-yr period at North Platte, NE. When the experiment was initiated at North Platte, no weeds were present before corn planting. It took 4 yr before triazine-resistant kochia became a problem before corn planting in plots treated with atrazine, but these were controlled by other operations prior to corn harvest. In the cultivated check, green foxtail densities before harvest increased from 0 in 1985 to 32 plants 100 m−2in 1991. Annual applications of dicamba plus 2,4-D 10 d early preplant followed by cultivation controlled triazine-resistant kochia and velvetleaf, but common lambsquarters, nightshade species, and green foxtail increased. Volunteer corn was controlled with cultivation. After 3 yr at Mitchell, the annual weed population increased 10-fold in the cultivated check. Thus, corn yields were reduced 64% with two cultivations compared with an annual early preplant application of dicamba plus 2,4-D followed by alachlor plus cyanazine PRE and two cultivations. With two cultivations under low annual weed populations at North Platte, grain yield from the cultivated check treatment was not different from annual treatments of herbicides after 7 yr. Metolachlor plus atrazine occasionally caused a reduction in corn grain yields.


1997 ◽  
Vol 11 (3) ◽  
pp. 537-542 ◽  
Author(s):  
Thomas L. Rabaey ◽  
R. Gordon Harvey

Field studies were conducted in 1994 and 1995 to determine the contribution of PRE applications of alachlor, metolachlor, acetochlor, SAN 582H, or pendimethalin on woolly cupgrass and wild-proso millet control when followed by POST nicosulfuron at 0, 0.018, 0.027, or 0.036 kg ai/ha. Sequential treatments controlled woolly cupgrass and wild-proso millet greater than single applications of PRE herbicides, which when applied alone resulted in the least wild-proso millet control and lowest corn grain yield. Lack of complete woolly cupgrass control with POST nicosulfuron alone resulted in corn grain yield that was less than with sequential treatments but was equal to PRE treatments. Wild-proso millet control with nicosulfuron at 0.027 kg/ha resulted in corn grain yield that was less than with sequential treatments, but greater than with all PRE treatments except for SAN 582H. All PRE herbicides, regardless of early season performance, when followed by nicosulfuron resulted in woolly cupgrass and wild-proso millet control that was similar. Woolly cupgrass seed production compared to the nontreated check was reduced 98% with acetochlor followed by nicosulfuron. Sequential treatments provided the most consistent woolly cupgrass and wild-proso millet control, the highest corn grain yield, and the greatest reduction in woolly cupgrass and wild-proso millet seed production.


2006 ◽  
Vol 20 (3) ◽  
pp. 640-645 ◽  
Author(s):  
Ehsan Bijanzadeh ◽  
Hossein Ghadiri

Field studies were conducted at Shiraz, Iran, during 2000 and 2001 to investigate the effect of separate and combined herbicide treatments on weed control and corn yield. Separate and combined herbicide treatments included 14 combinations applied at two rates. Herbicides reduced weed biomass compared with the weedy check. In both years, maximum reduction in weed biomass was observed with atrazine plus alachlor at 1 + 2.44 and 1.5 + 1.92 kg ai/ha and minimum reduction in weed biomass was observed with rimsulfuron at 0.02 and 0.04 kg/ha. In 2000 and 2001, 2,4-D plus MCPA at 0.36 + 0.31 and 0.54 + 0.46 kg/ha, and alachlor plus 2,4-D plus MCPA at 1.92 + 0.54 + 0.46 kg/ha, and 2.44 + 0.36 + 0.31 kg/ha, controlled 80 to 100% of field bindweed and rimsulfuron at 0.02 and 0.04 kg/ha controlled 17 to 70% of field bindweed. All herbicide treatments controlled redroot pigweed 60 to 100%. In 2000, at 6 and 17 WAP, minimum biomass reduction of Chinese-lantern-plant was observed with 2,4-D plus MCPA at 0.36 + 0.31 and 0.54 + 0.46 kg/ha, and primisulfuron plus prosulfuron at 0.02 + 0.02 and 0.03 + 0.03 kg/ha. Rimsulfuron plus primisulfuron plus prosulfuron at 0.02 + 0.03 + 0.03 and 0.04 + 0.02 + 0.02 kg/ha reduced johnsongrass biomass 96 to 100% and the efficacy of rimsulfuron increased when tank mixed with primisulfuron plus prosulfuron. Results of both years showed that all herbicide treatments increased corn grain yield as compared with the weedy check. Maximum corn grain yield was obtained with combinations of atrazine plus alachlor at 1 + 2.44 and 1.5 + 1.92 kg/ha.


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