Nitrogen management will influence threshold values of green foxtail (Setaria viridis) in corn

Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 975-986 ◽  
Author(s):  
R. Jason Cathcart ◽  
Clarence J. Swanton
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Response Surfaces ◽  
Corn Yield ◽  
Threshold Values ◽  
Corn Production ◽  
Green Foxtail ◽  
N Rates ◽  
Corn Grain ◽  
Corn Grain Yield

Environmental legislation may impose limitations on the quantity of nitrogen (N) used in corn production on the basis of soil type and ground water flow. If N rates are reduced, this might influence the relative competitiveness of weed species. Therefore, the objectives of this research were to develop a surface response model to provide estimations of the effect of differing N rates on threshold values of green foxtail in corn and to use this model as a theoretical framework for hypothesis testing. Field experiments were conducted from 1999 to 2001 to examine the interaction of N rate and green foxtail density on corn grain yield. The experiment was designed as a two-factor factorial with N levels ranging from 0 to 200 kg N ha−1and targeted green foxtail densities ranging from 0 to 300 green foxtail plants m−2. The addition of up to 200 kg N ha−1increased corn grain yield in both weed-free and weedy treatments. Corn yield loss attributed to green foxtail ranged from 35 to 40% at 0 kg N ha−1to 12 to 17% at 200 kg N ha−1. Ridge analysis of the response surfaces indicated that optimal corn grain yield could be achieved at derived values of 131 to 138 kg N ha−1while maintaining a green foxtail density of 8 to 9 green foxtail plants m−2on a sandy soil with less than 2% organic matter. The analyses of simulation results led to the generation of hypotheses of practical relevance to N management. On the basis of the generated hypotheses, a legislated reduction in N or an increase in the cost of N fertilizer would result in a lower threshold value for green foxtail in corn. If legislation were to ban the use of all herbicides in corn production, higher N rates or an increase in mechanical weed control measures would be required to offset yield losses caused by green foxtail. The human health and environmental consequences of such legislation would be significant.

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.

scholarly journals Corn yield response to weed and fall armyworm controls

2010 ◽  
Vol 28 (1) ◽  
pp. 103-111 ◽  
Author(s):  
M.S. Lima ◽  
P.S.L. Silva ◽  
O.F. Oliveira ◽  
K.M.B. Silva ◽  
F.C.L. Freitas
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Block Design ◽  
Fall Armyworm ◽  
Yield Response ◽  
Corn Yield ◽  
Water Control ◽  
Neem Extract ◽  
Corn Grain ◽  
Corn Grain Yield

The interference imposed the by weeds on corn decreases practically all vegetative characteristics. As consequence, the green ear and grain yield are also reduced. Losses due to the fall armyworm (Spodoptera frugiperda) attack can reduce corn grain yield up to 34%. In general, weed and insect control issues are addressed separately in research papers. Nevertheless, interaction between weeds and insects may exist. This study aimed to evaluate green ear and corn grain yield response to weed and fall armyworm control. A completely randomized block design with split-plots and five replicates was adopted. Corn cultivar AG 1051 was grown under weedy conditions or with control by hand hoeings performed at 20 and 40 days after planting. Fall armyworm control (applied to subplots) was performed with sprays of water (control), deltamethrin (5g active ingredient ha-1); neem oil, at 0.5% (diluted in water), and neem leaf extract at 5%. Each product was sprayed three times, at seven-day intervals, starting at the 7th day after planting, using 150 L ha-1 of the tank solution. Dry mass of the above-ground part, internode diameter, leaf length, leaf width, leaf area, green ear yield and grain yield of corn were reduced due to the lack of weed control. Fall armyworm control in the weeded plots did not influence green ear yield and grain yield, except green mass of marketable, husked ears, which was reduced when the caterpillar was not controlled. Without weed control, neem extracts and deltamethrin sprays provided highest yields of number and total weight of green ears with husks, number and weight of marketable ears with husks and number of marketable ears without husks. The best results for husked ear mass and for grain yield were obtained with neem extract and deltamethrin, respectively.

Simulation of Spring-Seeded Smother Plants for Weed Control in Corn (Zea mays)

Weed Science ◽  
1994 ◽  
Vol 42 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Robert L. De Haan ◽  
Donald L. Wyse ◽  
Nancy J. Ehlke ◽  
Bruce D. Maxwell ◽  
Daniel H. Putnam
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Field Experiments ◽  
Dry Weight ◽  
Yield Reduction ◽  
Maximum Height ◽  
Corn Yield ◽  
Yellow Mustard ◽  
Corn Silk ◽  
Corn Grain

Field experiments were conducted to determine the effect of a short-term spring-seeded smother plant on corn development and weed control. Yellow mustard was managed to provide interference durations of 2,4,6, or 8 wk, and maximum height of 10 or 20 cm. Three yellow mustard planting patterns and eight seeding rates were evaluated during 1989 and 1990 at St. Paul and Rosemount, MN. Yellow mustard seeded at 2120 seeds m−2with an interference duration of 4 wk and a maximum height of 10 cm decreased corn yield 17% and reduced weed dry weight 4 wk after yellow mustard emergence an average of 66%. Yellow mustard with a 2-wk interference duration did not reduce weed dry weight. Yellow mustard seeded at 2120 seeds m−2with a 6- or 8-wk life cycle and 10-cm height reduced weed dry weight at the end of the interference period an average of 82% but delayed corn silk emergence an average of 5.3 d and reduced average grain yield 19%. Increasing yellow mustard height from 10 to 20 cm delayed corn silk emergence and reduced grain yield but did not decrease weed dry weight. Yellow mustard with an interference duration of 4 wk and a maximum height of 10 cm, seeded over the corn row at 530 seeds m−2, reduced weed dry weight 4 wk after mustard emergence an average of 51%, and resulted in an average corn grain yield reduction of 4%, compared with corn grown in monoculture averaged over weedy and weed-free treatments. These results suggest that it may be possible to develop spring-seeded smother plants that reduce weed biomass up to 80% but have only a small impact on corn yield.

Effect of cereal rye and canola on winter and summer annual weed emergence in corn

2020 ◽  
Vol 34 (6) ◽  
pp. 787-793
Author(s):  
Stephanie A. DeSimini ◽  
Kevin D. Gibson ◽  
Shalamar D. Armstrong ◽  
Marcelo Zimmer ◽  
Lucas O.R. Maia ◽  
...  
Keyword(s):  
Grain Yield ◽  
Cover Crops ◽  
Cover Crop ◽  
Corn Yield ◽  
Crop Species ◽  
Weed Biomass ◽  
Cereal Rye ◽  
Giant Ragweed ◽  
Corn Grain ◽  
Corn Grain Yield

AbstractField experiments were conducted in 2017 and 2018 at two locations in Indiana to evaluate the influence of cover crop species, termination timing, and herbicide treatment on winter and summer annual weed suppression and corn yield. Cereal rye and canola cover crops were terminated early or late (2 wk before or after corn planting) with a glyphosate- or glufosinate-based herbicide program. Canola and cereal rye reduced total weed biomass collected at termination by up to 74% and 91%, in comparison to fallow, respectively. Canola reduced horseweed density by up to 56% at termination and 57% at POST application compared to fallow. Cereal rye reduced horseweed density by up to 59% at termination and 87% at POST application compared to fallow. Canola did not reduce giant ragweed density at termination in comparison to fallow. Cereal rye reduced giant ragweed density by up to 66% at termination and 62% at POST application. Termination timing had little to no effect on weed biomass and density reduction in comparison to the effect of cover crop species. Cereal rye reduced corn grain yield at both locations in comparison to fallow, especially for the late-termination timing. Corn grain yield reduction up to 49% (4,770 kg ha–1) was recorded for cereal rye terminated late in comparison to fallow terminated late. Canola did not reduce corn grain yield in comparison to fallow within termination timing; however, late-terminated canola reduced corn grain yield by up to 21% (2,980 kg ha–1) in comparison to early-terminated fallow. Cereal rye can suppress giant ragweed emergence, whereas canola is not as effective at suppressing large-seeded broadleaves such as giant ragweed. These results also indicate that early-terminated cover crops can often result in higher corn grain yields than late-terminated cover crops in an integrated weed management program.

Postemergence herbicide application timing effects on annual grass control and corn (Zea mays) grain yield

Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 138-143 ◽  
Author(s):  
Larry S. Tapia ◽  
Thomas T. Bauman ◽  
Robert G. Harvey ◽  
James J. Kells ◽  
George Kapusta ◽  
...  
Keyword(s):  
Grain Yield ◽  
Corn Production ◽  
Tall Grass ◽  
Application Timing ◽  
Proso Millet ◽  
Giant Foxtail ◽  
Woolly Cupgrass ◽  
And Control ◽  
Corn Grain ◽  
Corn Grain Yield

Giant foxtail, woolly cupgrass, and wild-proso millet infest millions of hectares of land devoted to corn production in the midwestern U.S. Control of these species and effects on corn grain yield were evaluated at various timings using POST applications of nicosulfuron vs. applications of various PRE herbicides at 17 locations across the midwestern U.S. in 1992 and 1993. Nicosulfuron applied to 5 to 10 cm giant foxtail and woolly cupgrass provided greater control than that observed with selected PRE herbicides. Giant foxtail control with nicosulfuron averaged 88%, and control of woolly cupgrass averaged 77% across all sites. Nicosulfuron, applied to 5 to 10 cm wild-proso millet, provided a level of control similar to that of selected PRE herbicides. Corn grain yield was greater when giant foxtail was controlled POST with nicosulfuron vs. PRE control with selected soil-applied herbicides. Corn grain yields were similar when nicosulfuron was applied POST to 5 to 10 cm woolly cupgrass or wild-proso millet vs. PRE control of these grass weeds. Across a broad range of geographical locations, nicosulfuron, applied POST to 5 to 10 cm tall grass, provided greater or similar levels of weed control vs. the selected PRE herbicides, with no deleterious effect on grain yield.

Long-term (35 years) effects of fertilization, rotation and weather on corn yields

1995 ◽  
Vol 75 (2) ◽  
pp. 355-362 ◽  
Author(s):  
C. F. Drury ◽  
C. S. Tan
Keyword(s):  
Grain Yield ◽  
Crop Rotation ◽  
Potential Evapotranspiration ◽  
Corn Yield ◽  
Weather Factors ◽  
Grain Yields ◽  
Continuous Corn ◽  
Corn Grain ◽  
Corn Grain Yield

Long-term effects of fertilization, crop rotation and weather factors [temperature, precipitation, net radiation, maximum (potential) evapotranspiration (ET) and corn heat units (CHU)] on the sustainability of corn grain yields were investigated over 35 yr. Treatments included fertilized and unfertilized continuous com and rotation corn-oats-alfalfa-alfalfa. The fertilized rotation corn treatment produced the greatest corn grain yields (15% moisture content) with an average of 7.75 t ha−1 followed by the fertilized continuous corn treatment with 6.02 t ha−1. Fertilization increased grain yield for continuous corn treatments by 279% and increased grain yields in the rotational corn treatments by 70%. Corn grain yields increased with time with the fertilized rotation treatment, remained relatively constant with the fertilized continuous corn and decreased with the unfertilized treatments. Growing season precipitation was the only weather variable tested which was significantly related to corn grain yield. Precipitation in July was proportional to corn grain yield for all fertilized treatments. Weather variation played little role for unfertilized corn. Continuous corn production was sustained (yields did not decrease with time) when fertilizer was added. There was a considerable yield advantage with fertilized corn when grown in a rotation compared with fertilized continuous corn. Fertilization and crop rotation practices increased and buffered corn yields. Key words: Long-term, corn, yield, fertilization, rotation, weather

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.

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.

scholarly journals Monitoring Within-Field Variability of Corn Yield using Sentinel-2 and Machine Learning Techniques

2019 ◽  
Vol 11 (23) ◽  
pp. 2873 ◽  
Author(s):  
Ahmed Kayad ◽  
Marco Sozzi ◽  
Simone Gatto ◽  
Francesco Marinello ◽  
Francesco Pirotti
Keyword(s):  
Machine Learning ◽  
Grain Yield ◽  
Precision Agriculture ◽  
Machine Learning Techniques ◽  
Corn Yield ◽  
Learning Techniques ◽  
Field Variability ◽  
Sentinel 2 ◽  
Corn Grain ◽  
Corn Grain Yield

Monitoring and prediction of within-field crop variability can support farmers to make the right decisions in different situations. The current advances in remote sensing and the availability of high resolution, high frequency, and free Sentinel-2 images improve the implementation of Precision Agriculture (PA) for a wider range of farmers. This study investigated the possibility of using vegetation indices (VIs) derived from Sentinel-2 images and machine learning techniques to assess corn (Zea mays) grain yield spatial variability within the field scale. A 22-ha study field in North Italy was monitored between 2016 and 2018; corn yield was measured and recorded by a grain yield monitor mounted on the harvester machine recording more than 20,000 georeferenced yield observation points from the study field for each season. VIs from a total of 34 Sentinel-2 images at different crop ages were analyzed for correlation with the measured yield observations. Multiple regression and two different machine learning approaches were also tested to model corn grain yield. The three main results were the following: (i) the Green Normalized Difference Vegetation Index (GNDVI) provided the highest R2 value of 0.48 for monitoring within-field variability of corn grain yield; (ii) the most suitable period for corn yield monitoring was a crop age between 105 and 135 days from the planting date (R4–R6); (iii) Random Forests was the most accurate machine learning approach for predicting within-field variability of corn yield, with an R2 value of almost 0.6 over an independent validation set of half of the total observations. Based on the results, within-field variability of corn yield for previous seasons could be investigated from archived Sentinel-2 data with GNDVI at crop stage (R4–R6).

Control of glyphosate-resistant horseweed (Conyza canadensis L.) with tiafenacil mixes in corn

2021 ◽  
pp. 1-12
Author(s):  
Nader Soltani ◽  
Christy Shropshire ◽  
Peter H. Sikkema
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Conyza Canadensis ◽  
Herbicide Application ◽  
Industry Standards ◽  
Dry Biomass ◽  
Corn Fields ◽  
Biomass Reduction ◽  
Corn Grain ◽  
Corn Grain Yield

Abstract Four field experiments were completed in commercial corn fields during 2019 and 2020 to determine glyphosate-resistant (GR) horseweed control in corn with tiafenacil alone or in combination with bromoxynil, dicamba, or tolpyralate applied preplant (PP). Corn planted 1 to 10 d after herbicide application was not injured with any of the herbicides tested. GR horseweed interference reduced corn grain yield 32% when left uncontrolled. Herbicides reduced GR horseweed interference and resulted in corn grain yield that was similar to the weed-free control. Glyphosate (900 g ae ha−1) + tiafenacil at 12.5, 25, and 37.5 g ha−1 controlled GR horseweed 63, 68, and 72% at 4 weeks after treatment (WAT) and decreased GR horseweed density 64, 43, and 83%, and dry biomass 69, 55, and 83%, respectively. Glyphosate + tiafenacil at 12.5, 25, and 37.5 g ha−1 plus bromoxynil (280 g ai ha−1) controlled GR horseweed 81, 88, and 87% at 4 WAT, and reduced GR horseweed density 82, 94, and 93% and dry biomass 93, 93, and 98%, respectively. Glyphosate + tiafenacil at 12.5, 25, and 37.5 g ha−1 plus dicamba (300 g ai ha−1) controlled GR horseweed 86, 88, and 88% at 4 WAT and decreased GR horseweed density 76, 89, and 86% and dry biomass 94, 98, and 98%, respectively. Glyphosate + tiafenacil at 12.5, 25, and 37.5 g ha−1 plus tolpyralate (30 g ai ha−1) controlled GR horseweed 90, 90, and 91% at 4 WAT and decreased GR horseweed density 93, 91, and 95% and dry biomass 98, 97, and 97%, respectively. The industry standards in Ontario, glyphosate + dicamba/atrazine and glyphosate + saflufenacil/dimethenamid-p controlled GR horseweed 95 and 100% at 4, 8 and 12 WAT and caused a 99 and 100% density or biomass reduction, respectively.

Sign in / Sign up

Export Citation Format

Share Document