The Critical Period of Johnsongrass (Sorghum halepense) Control in Field Corn (Zea mays)

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 944-947 ◽  
Author(s):  
Hani Z. Ghosheh ◽  
David L. Holshouser ◽  
James M. Chandler
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Critical Period ◽  
Sorghum Halepense ◽  
Control Methods ◽  
Field Corn ◽  
Hand Weeding ◽  
Corn Grain ◽  
Corn Grain Yield

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.

Influence of Density on Johnsongrass (Sorghum halepense) Interference in Field Corn (Zea mays)

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 879-883 ◽  
Author(s):  
Hani Z. Ghosheh ◽  
David L. Holshouser ◽  
James M. Chandler
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Maximum Density ◽  
Sorghum Halepense ◽  
Constant Density ◽  
Yield Losses ◽  
Density Dependent ◽  
Field Corn ◽  
Corn Grain ◽  
Corn Grain Yield

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.

Annual Grass Control in Corn (Zea mays) with Primisulfuron Combined with Nicosulfuron

1997 ◽  
Vol 11 (1) ◽  
pp. 171-175 ◽  
Author(s):  
Thomas L. Rabaey ◽  
R. Gordon Harvey
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Annual Grass ◽  
Grain Yields ◽  
Proso Millet ◽  
Field Corn ◽  
Giant Foxtail ◽  
Woolly Cupgrass ◽  
Corn Grain ◽  
Corn Grain Yield

Efficacy of primisulfuron and reduced rates of nicosulfuron on woolly cupgrass, wild-proso millet, and giant foxtail in field corn was evaluated in 1994 and 1995. Nicosulfuron was applied at 18, 27, and 36 g ai/ha alone and with 20 g ai/ha primisulfuron. Woolly cupgrass control from nicosulfuron at 18 and 27 g/ha was less than control from 36 g/ha (79% and 84% vs. 90%, respectively). Woolly cupgrass control was 5% greater when primisulfuron was combined with nicosulfuron at 27 and 36 g/ha than when nicosulfuron was applied alone. Corn grain yields were similar among all nicosulfuron plus primisulfuron treatments applied to control woolly cupgrass in 1994. In 1995, corn grain yield was increased 900 kg/ha when primisulfuron was combined with nicosulfuron at 18 g/ha compared to nicosulfuron applied at the same rate alone. Wild-proso millet control 3 WAT with nicosulfuron at 18 g/ha was less than control with nicosulfuron at 36 g/ha. Wild-proso millet control 8 WAT with nicosulfuron alone was greater than when nicosulfuron at any rate was applied with primisulfuron. No differences in corn grain yields were observed across nicosulfuron rates or combinations with primisulfuron to control wild-proso millet either year. Giant foxtail control and corn grain yield were not affected by nicosulfuron rate or combined applications of nicosulfuron and primisulfuron either year.

GRAIN YIELD COMPARISON OF PURE STANDS AND MIXTURES OF DIFFERENT PROPORTIONS FOR TWO HYBRIDS OF MAIZE

1985 ◽  
Vol 65 (3) ◽  
pp. 481-485 ◽  
Author(s):  
G. J. HOEKSTRA ◽  
L. W. KANNENBERG ◽  
B. R. CHRISTIE
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Zea Mays L ◽  
Pure Stand ◽  
Higher Plant ◽  
Data Support ◽  
Plant Densities ◽  
The Difference ◽  
Corn Grain ◽  
Corn Grain Yield

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

Application Timing for Weed Control in Corn (Zea mays) with Dicamba Tank Mixtures

1997 ◽  
Vol 11 (3) ◽  
pp. 602-607 ◽  
Author(s):  
Eric Spandl ◽  
Thomas L. Rabaey ◽  
James J. Kells ◽  
R. Gordon Harvey
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Weed Control ◽  
Field Studies ◽  
Corn Yield ◽  
Application Timing ◽  
Common Lambsquarters ◽  
Giant Foxtail ◽  
Corn Grain ◽  
Corn Grain Yield

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.

Effects of Sublethal Concentrations of Bentazon, Fluazifop, Haloxyfop, and Sethoxydim on Corn (Zea mays)

Weed Science ◽  
1986 ◽  
Vol 34 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Jon P. Chernicky ◽  
Fred W. Slife
Keyword(s):  
Zea Mays ◽  
Seed Germination ◽  
Grain Yield ◽  
Seed Weight ◽  
Growth Stage ◽  
Field Studies ◽  
Propanoic Acid ◽  
Sublethal Concentrations ◽  
Corn Grain ◽  
Corn Grain Yield

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.

The Effect of Sethoxydim on Corn (Zea mays) and Giant Foxtail (Setaria faberi)

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 600-603 ◽  
Author(s):  
Jon P. Chernicky ◽  
Roger Gast ◽  
Fred W. Slife
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Field Studies ◽  
Setaria Faberi ◽  
Giant Foxtail ◽  
Over The Top ◽  
Corn Grain ◽  
Corn Grain Yield

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).

Cultivation and Herbicides for Weed Control in Corn

Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 232-234 ◽  
Author(s):  
K. P. Buchholtz ◽  
R. E. Doersch
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Weed Control ◽  
Corn Yield ◽  
Triazine Herbicides ◽  
Grain Yields ◽  
Yield Increase ◽  
Weed Growth ◽  
Corn Grain ◽  
Corn Grain Yield

Corn (Zea mays L.) plots receiving broadcast spray applications of triazine herbicides without cultivation yielded as much as plots receiving the standard two cultivations for weed control. One cultivation resulted in an average 6% increase in corn grain yield on herbicide treated plots. This yield increase probably was due to improved weed control. Weed growth reduced grain yields an average of 1.23 bu/A for each 100 lb/A of dry weeds. In some experiments, increases in corn yield due to improved weed control by cultivation on plots treated with herbicides were less than increases expected based on weed growth reductions. This disparity may have been due to injury to the corn by cultivation.

Corn (Zea mays) Yield in Relationship to Johnsongrass (Sorghum halepense) Population

Weed Science ◽  
1986 ◽  
Vol 34 (3) ◽  
pp. 449-451 ◽  
Author(s):  
Leo E. Bendixen
Keyword(s):  
Triticum Aestivum ◽  
Zea Mays ◽  
Glycine Max ◽  
Grain Yield ◽  
Sorghum Halepense ◽  
Kernel Development ◽  
Grain Yields ◽  
Herbicide Treatments ◽  
Maize Grain ◽  
Corn Grain

Corn (Zea maysL.) grain yield was measured in a 5-yr study at two locations in central Ohio in relationship to johnsongrass [Sorghum halepense(L.) Pers. # SORHA] populations infesting the plots. Herbicide treatments were EPTC + R-25788 (S-ethyl dipropyl carbamothioate) + (N,N-diallyl-2,2-dichloroacetamide) at 6.7 kg ai/ha to corn in a monoculture and in a 3-yr rotation of winter wheat (Triticum aestivumL.), corn, and soybeans [Glycine max(L.) Merr.], with each crop being grown each year. There were large increases in johnsongrass populations in the monocultures during the course of the 5-yr study, and corn grain yield fell to zero, even though ear formation was not greatly reduced. Conversely, johnsongrass populations in the rotation were low and maize grain yields and numbers of ears remained high. The differential in grain yields between the two treatments was apparently due chiefly to lack of pollination or kernel development, since ears were formed in approximately equal numbers, except for the last year.

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
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Field Studies ◽  
Good Tolerance ◽  
Corn Grain ◽  
Corn Grain Yield

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.

CORRELATIONS BETWEEN GRAIN YIELD AND PERCENTAGE GRAIN MOISTURE AT HARVEST IN ONTARIO HYBRID CORN TRIALS

1989 ◽  
Vol 69 (1) ◽  
pp. 223-225 ◽  
Author(s):  
D. E. MATHER ◽  
L. W. KANNENBERG
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Zea Mays L ◽  
Trial Data ◽  
Hybrid Corn ◽  
Grain Moisture ◽  
Positive Correlations ◽  
Performance Trial ◽  
Corn Grain ◽  
Corn Grain Yield

The correlation between hybrid corn (Zea mays L.) grain yield and percentage grain moisture at harvest was measured in Ontario performance trial data. Positive correlations were detected in mid- to full-season areas.Key words: Zea mays L., hybrid corn, grain yield, grain moisture, maturity, correlation

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