scholarly journals Interactions of Nitrogen Source and Rate and Weed Removal Timing Relative to Nitrogen Content in Corn and Weeds and Corn Grain Yield

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Alexandra M. Knight ◽  
Wesley J. Everman ◽  
David L. Jordan ◽  
Ronnie W. Heiniger ◽  
T. Jot Smyth
Keyword(s):  
Grain Yield ◽  
Weed Management ◽  
Management Strategies ◽  
Field Studies ◽  
Weed Species ◽  
Weed Interference ◽  
Coated Urea ◽  
N Fertility ◽  
Corn Grain ◽  
Corn Grain Yield

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.

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.

Herbicide Rate Effects on Weed and Root Maggot Dynamics in Canola

Weed Science ◽  
2008 ◽  
Vol 56 (3) ◽  
pp. 477-483 ◽  
Author(s):  
Jim S. Broatch ◽  
Lloyd M. Dosdall ◽  
John T. O'Donovan ◽  
K Neil Harker ◽  
George W. Clayton
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Management Strategies ◽  
Dry Weight ◽  
Field Studies ◽  
Crop Damage ◽  
Weed Species ◽  
Alternate Host ◽  
Insect Management ◽  
Root Maggot

Weed management strategies can influence insect infestations in field crops, yet no attempts have been made previously to manipulate weed populations in canola for integrated weed and insect management. Field studies were conducted during 2003 to 2005 at Lacombe and Beaverlodge, Alberta, Canada to manipulate weed and root maggot, Delia spp. (Diptera: Anthomyiidae), interactions in canola. Densities of monocot weeds were varied by altering herbicide applications, with rates ranging from 0 to 100% of the rate recommended. Weed populations declined, and yields were variable with increased herbicide rates. Root maggot damage decreased with increases in monocot weed dry weight for both canola species at both study sites. Results support the hypothesis that heterogenous environments, arising from mixed populations of monocot weeds with canola, minimize opportunities for females of Delia spp. to complete the behavioral sequence required for oviposition, leading to reduced infestation levels in weedy systems. However, effects of dicot weeds on root maggot infestations varied between sites as a result of site-related differences in weed species complexes. When wild mustard was common, crop damage increased, because this weed can serve as an alternate host for root maggots. The study emphasizes the importance of adopting crop management practices that are compatible for both weed and root maggot control.

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).

Sequential Applications Control Woolly Cupgrass (Eriochloa villosa) and Wild-Proso Millet (Panicum miliaceum) in Corn (Zea mays)

1997 ◽  
Vol 11 (3) ◽  
pp. 537-542 ◽  
Author(s):  
Thomas L. Rabaey ◽  
R. Gordon Harvey
Keyword(s):  
Grain Yield ◽  
Seed Production ◽  
Field Studies ◽  
Proso Millet ◽  
Millet Seed ◽  
Woolly Cupgrass ◽  
Eriochloa Villosa ◽  
Sequential Treatments ◽  
Corn Grain ◽  
Corn Grain Yield

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.

Effect of Separate and Combined Treatments of Herbicides on Weed Control and Corn (Zea mays) Yield

2006 ◽  
Vol 20 (3) ◽  
pp. 640-645 ◽  
Author(s):  
Ehsan Bijanzadeh ◽  
Hossein Ghadiri
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Field Studies ◽  
Corn Yield ◽  
Weed Biomass ◽  
Field Bindweed ◽  
Herbicide Treatments ◽  
Biomass Reduction ◽  
Corn Grain ◽  
Corn Grain Yield

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.

Rimsulfuron for Postemergence Weed Control in Corn in Humid Tropical Environments of Nigeria

2007 ◽  
Vol 21 (4) ◽  
pp. 977-981 ◽  
Author(s):  
David Chikoye ◽  
Udensi E. Udensi ◽  
A. Fontem Lum ◽  
Friday Ekeleme
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Field Studies ◽  
Small Scale ◽  
International Institute ◽  
Tropical Environments ◽  
Perennial Weeds ◽  
Dry Biomass ◽  
Corn Grain ◽  
Corn Grain Yield

Cogongrass and guineagrass are serious perennial weeds in small-scale farms in lowland subhumid zones of West Africa. Field studies were conducted in 2002 and 2003 at two sites in Ibadan, Nigeria [Ijaye and the International Institute of Tropical Agriculture (IITA)], to evaluate the effect of rimsulfuron on weed communities dominated by cogongrass and guineagrass in corn. At both sites, treatments were rimsulfuron dosages of 0 (nontreated control), 10, 20, 30, 40, 50, 60, 70, and 80 g ai/ha. Rimsulfuron did not cause any visible phytotoxicity on the corn at any dosage at either site. There was a rapid increase in weed control as the dosage of rimsulfuron increased from 0 to 20 g/ha. Weed control was not improved at rates higher than 20 g/ha. Rimsulfuron was very effective against sedges,Ipomoea involucrata, Bengal dayflower, gulf leafflower, old-world diamond-flower, and wild jute providing more than 80% control at dosages between 10 and 20 g/ha at Ijaye. Rimsulfuron was less effective for cogongrass, with a maximum of only 38% control observed. At IITA, the herbicide was very effective against guineagrass, Bengal dayflower, nodeweed, coat buttons, redfruit passionflower, and waterleaf; all of which were controlled more than 70% with any rate of rimsulfuron. Regression analysis showed that the dosage of rimsulfuron required to reduce shoot dry biomass by 70% was 5 g/ha for guineagrass and 35 g/ha for cogongrass at 3 wk after treatment (WAT). At crop maturity, the dosage of rimsulfuron required to reduce shoot dry biomass by 70% was 43 g/ha for guineagrass and 200 g/ha for cogongrass. The dry biomass of cogongrass and guineagrass was higher at crop harvest than at 2 WAT regardless of herbicide dosage. Corn grain yield was 1.8 times higher at IITA than at Ijaye. At both sites, corn grain yield increased with increased herbicide dosage. Maximum corn grain yields were obtained at a rimsulfuron dosage of 20 g/ha.

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.

scholarly journals Weed control in corn via intercropping with gliricidia sown by broadcasting

2011 ◽  
Vol 29 (3) ◽  
pp. 535-543 ◽  
Author(s):  
A.M Oliveira ◽  
P.S.L Silva ◽  
C.C Albuquerque ◽  
C.M.S.B Azevedo ◽  
M.J Cardoso ◽  
...  
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Environmental Degradation ◽  
Block Design ◽  
Planting Density ◽  
Seeding Density ◽  
Weed Species ◽  
Randomized Block Design ◽  
Corn Grain ◽  
Corn Grain Yield

There has been interest in reducing the use of herbicides for weed control in order to decrease environmental degradation problems. The objective of this study was to evaluate the effects of gliricidia planting density sown by broadcasting and intercopping on green ear and corn grain yield as well as on weed control. A randomized block design with split-plots and five replicates were adopted. Cultivars AG 1051, BM 2022, and BM 3061, assigned to plots, were submitted to the following treatments: no hoeing, two hoeings (at 20 and 40 days after sowing), and intercropped with gliricidia sown at densities of 10 and 20 seeds m-2. Thirty weed species occurred in the experiment area, with Cucumis anguria as the most frequent ones. Cultivar BM 2022 was the best for the total number of ears (TNE) and number (NMHE) and weight of marketable husked ears. Together with cultivar AG 1051, this cultivar had the highest total weight and marketable unhusked ear weight (MUEW). However, the cultivars did not differ with respect to grain yield (GY). The highest green ear and corn grain yield and weed control percentages were obtained with two hoeings; in MUEW, NMHE and GY, intercropping provided intermediate means in comparison with those obtained in hoed and non-hoed plots, indicating that gliricidia was partially beneficial to corn. Increased gliricidia seeding density heightened the benefits to corn (TNE and MUEW). The lack of hoeing produced the poorest green ear and grain yields.

A Comparison of Economic and Economic Optimum Thresholds for Two Annual Weeds in Soybeans

1992 ◽  
Vol 6 (1) ◽  
pp. 228-235 ◽  
Author(s):  
Troy A. Bauer ◽  
David A. Mortensen
Keyword(s):  
Weed Management ◽  
Threshold Model ◽  
Field Studies ◽  
Weed Species ◽  
Financial Benefit ◽  
Weed Interference ◽  
Economic Thresholds ◽  
Annual Weeds ◽  
Optimum Threshold

Long term weed management programs for annual weeds should take into account seed production as well as yield losses from weeds. In this research economic optimum thresholds, determined with a simulation model, were compared to the economic thresholds derived from field studies with common sunflower and velvetleaf in soybean. An economic optimum threshold model, including a biological submodel and a submodel evaluating the financial benefit from controlling each weed species in soybean, was constructed to estimate the biological events and processes and economic costs of each weed. Long-term weed management programs were simulated in continuous soybean over a 15-yr period. The model optimized a POST treatment of bentazon by computing costs associated with weed interference and changes in estimated seedbank size. The economic optimum threshold populations were estimated to be 0.3 to 0.4 velvetleaf plants per 10 m2and 0.4 common sunflower plants per 10 m2. The economic thresholds calculated to be 2.6 velvetleaf plants per 10 m2and 1.5 common sunflower plants per 10 m2. The economic optimum threshold was calculated to be 7.5-fold and 3.6-fold lower than the economic thresholds for velvetleaf and common sunflower, respectively. The larger ratio for velvetleaf reflected the large quantity and longevity of seeds produced. The smaller ratio for common sunflower reflected the shorter persistence of the seeds and higher seed predation rates.

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