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.

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.

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 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.

scholarly journals Weed control in corn and weed sample size for growth evaluations

2014 ◽  
Vol 32 (1) ◽  
pp. 51-59 ◽  
Author(s):  
L.B. Tavella ◽  
P.S.L. Silva ◽  
V.R. Oliveira ◽  
P.L.O. Fernandes ◽  
R.P. Sousa
Keyword(s):  
Grain Yield ◽  
Sample Size ◽  
Weed Control ◽  
Block Design ◽  
Corn Yield ◽  
Weed Growth ◽  
Randomized Block Design ◽  
Experimental Variation ◽  
Yield Values ◽  
Viable Seeds

The objectives of this study were to evaluate baby corn yield, green corn yield, and grain yield in corn cultivar BM 3061, with weed control achieved via a combination of hoeing and intercropping with gliricidia, and determine how sample size influences weed growth evaluation accuracy. A randomized block design with ten replicates was used. The cultivar was submitted to the following treatments: A = hoeings at 20 and 40 days after corn sowing (DACS), B = hoeing at 20 DACS + gliricidia sowing after hoeing, C = gliricidia sowing together with corn sowing + hoeing at 40 DACS, D = gliricidia sowing together with corn sowing, and E = no hoeing. Gliricidia was sown at a density of 30 viable seeds m-2. After harvesting the mature ears, the area of each plot was divided into eight sampling units measuring 1.2 m² each to evaluate weed growth (above-ground dry biomass). Treatment A provided the highest baby corn, green corn, and grain yields. Treatment B did not differ from treatment A with respect to the yield values for the three products, and was equivalent to treatment C for green corn yield, but was superior to C with regard to baby corn weight and grain yield. Treatments D and E provided similar yields and were inferior to the other treatments. Therefore, treatment B is a promising one. The relation between coefficient of experimental variation (CV) and sample size (S) to evaluate growth of the above-ground part of the weeds was given by the equation CV = 37.57 S-0.15, i.e., CV decreased as S increased. The optimal sample size indicated by this equation was 4.3 m².

scholarly journals Phosphorus and Potassium Fertilizer Application Strategies in Corn–Soybean Rotations

Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 195 ◽  
Author(s):  
Timothy Boring ◽  
Kurt Thelen ◽  
James Board ◽  
Jason De Bruin ◽  
Chad Lee ◽  
...  
Keyword(s):  
Grain Yield ◽  
Seed Yield ◽  
Soybean Seed ◽  
Fertilizer Application ◽  
High Yield ◽  
Yield Response ◽  
Soil Test ◽  
Soil Test P ◽  
Corn Grain ◽  
Corn Grain Yield

To determine if current university fertilizer rate and timing recommendations pose a limitation to high-yield corn (Zea mays subsp. mays) and soybean (Glycine max) production, this study compared annual Phosphorous (P) and Potassium (K) fertilizer applications to biennial fertilizer applications, applied at 1× and 2× recommended rates in corn–soybean rotations located in Minnesota (MN), Iowa (IA), Michigan (MI), Arkansas (AR), and Louisiana (LA). At locations with either soil test P or K in the sub-optimal range, corn grain yield was significantly increased with fertilizer application at five of sixteen site years, while soybean seed yield was significantly increased with fertilizer application at one of sixteen site years. At locations with both soil test P and K at optimal or greater levels, corn grain yield was significantly increased at three of thirteen site years and soybean seed yield significantly increased at one of fourteen site years when fertilizer was applied. Site soil test values were generally inversely related to the likelihood of a yield response from fertilizer application, which is consistent with yield response frequencies outlined in state fertilizer recommendations. Soybean yields were similar regardless if fertilizer was applied in the year of crop production or before the preceding corn crop. Based on the results of this work across the US and various yield potentials, it was confirmed that the practice of applying P and K fertilizers at recommended rates biennially prior to first year corn production in a corn–soybean rotation does not appear to be a yield limiting factor in modern, high management production systems.

Evaluation of Application Program and Timing in Herbicide-Resistant Corn

2012 ◽  
Vol 26 (4) ◽  
pp. 617-621 ◽  
Author(s):  
Laura E. Lindsey ◽  
Wesley J. Everman ◽  
Andrew J. Chomas ◽  
James J. Kells
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Herbicide Application ◽  
Application Timing ◽  
Common Lambsquarters ◽  
Giant Foxtail ◽  
Residual Herbicide ◽  
Herbicide Programs ◽  
Corn Grain ◽  
Corn Grain Yield

Field studies were conducted from 2007 to 2009 in East Lansing, MI to evaluate three residual herbicide programs, three POST herbicide application timings, and two POST herbicides in glyphosate- and glufosinate-resistant corn. Herbicide programs included a residual PRE-applied herbicide followed by (fb) POST application (residual fb POST), a residual herbicide tank-mixed with a POST herbicide (residual + POST), and a nonresidual POST. Three POST herbicide application timings included early POST (EP), mid-POST (MP), and late POST (LP) at an average corn growth stage of V3/V4, V4/V5, and V5/V6, respectively. The two POST herbicides evaluated were glyphosate and glufosinate. Control of common lambsquarters and giant foxtail was evaluated 28 d after the LP application. Glyphosate often provided greater weed control than glufosinate. The LP application resulted in greater giant foxtail control compared with the EP application timing, which may be attributed to control of late-emerging weeds. The EP application timing improved common lambsquarters control compared with the LP application timing. The residual + POST program resulted in greater weed control compared with the residual fb POST program in all years. The effect of residual herbicide program, POST herbicide, and POST application timing on corn grain yield varied by year. In 2007, the use of glyphosate resulted in higher grain yield compared with glufosinate. In 2008, corn grain yield was the highest in the PRE fb POST program and with POST applications at EP and MP. To provide the most consistent weed control and minimize the likelihood of grain yield reductions, a PRE fb POST program applied at EP or MP is recommended.

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.

scholarly journals The response of corn (Zea mays L.) cultivars to row spacing under weed interference condition

2018 ◽  
Vol 111 (3) ◽  
pp. 525
Author(s):  
Gholamreza MOHAMMADI ◽  
Mehdi NOOKANI ◽  
Hamidreza MOHAMMADDOUST ◽  
Danial KAHRIZI
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Block Design ◽  
Seed Mass ◽  
Growing Season ◽  
Dry Mass ◽  
Row Spacing ◽  
Corn Yield ◽  
Weed Interference ◽  
Corn Grain

<p>This study was carried out in order to study the response of corn cultivars to row spacing and weed interference at the Research Farm of Agricultural and Natural Resources Faculty, Razi University, Kermanshah, Iran in 2011. The experiment was a split block factorial based on a randomized complete block design with three replications. Factors consisted of three corn cultivars ('KSC 704', 'Simon' and 'Maxima') and three plant row spacings (45, 60 and 75 cm) under weeded and un-weeded conditions for all of the growing season. Results indicated that for all three corn cultivars, the highest weed dry mass occurred in the row spacing of 75 cm. Weed interference throughout the growing season reduced corn grain yield by 20 %. This condition also significantly decreased corn yield components except the 100-seed mass. Increasing plant row spacing increased weed density, while decreased corn yield by 16.5 %. Corn cultivars were significantly different in terms of the number of seed per ear and 100-seed mass, as 'KSC 704' and 'Simon' showed the highest values for these yield components, respectively. However, the number of ear per plant and grain yield were not significantly different between the corn cultivars under study.</p>

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