Effect of cowpea intercropping on weed control and corn yieid

Herbicides have simplified weed control, but the use of herbicides, besides being costly, resulted in the selection of herbicide-resistant weed biotypes and has become an environmental contamination factor. Herbicide use reduction is one of the goals of modern agriculture, with several alternatives being investigated, including intercropping. The objective of this study was to evaluate the effects of cowpea and corn cultivar intercropping on weed control and corn green-ear (immature ears with 80% humidity grains) and grain yield. A completely randomized block design with split-plots and four replications was used. AG 1051, AG 2060 and PL 6880 corn cultivars (assigned to plots) were submitted to the four treatments: no weeding, two hoe-weeding (22 and 41 days after planting), and intercropping with cowpea (BR 14 and IPA 206 cultivars, with indeterminate growth). The cowpea was planted (with corn planting) between the corn rows, in pits 1.0 m apart, with two plants per pit. The corn cultivars did not differ from each other as to weed density (WD), fresh above-ground weed biomass (WB), green-ear yield and grain yields. Higher WD and WB mean values were found in no weeding subplots; lower mean values in two hoe-weeding subplots; and intermediate mean values in intercropped subplots, indicating that cowpea plants had, to a certain extent, control over weeds. The no-weeded plots and the intercropped plots had lower green-ear and grain yields. Although the cowpea cultivars had a certain control over weeds (mean reductions of 22.5 and 18.3%, in terms of green matter density and weight of the above-ground part of weeds, respectively), they also competed against the corn plants, leading to yield reduction (mean reductions of 17.0 and 32% in green ear and grain yield, respectively). The cowpea cultivars did not produce grain, certainly due to the strong competition exerted by the corn and weeds on cowpea plants.

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AGRONOMIC PERFORMANCE OF COWPEA CULTIVARS DEPENDING ON SOWING SEASONS IN THE CERRADO BIOME

Revista Caatinga ◽

10.1590/1983-21252017v30n211rc ◽

2017 ◽

Vol 30 (2) ◽

pp. 361-369 ◽

Cited By ~ 2

Author(s):

FERNANDO DA SILVA ALMEIDA ◽

FÁBIO LUIZ CHECCHIO MINGOTTE ◽

LEANDRO BORGES LEMOS ◽

MÁRCIO JOSÉ DE SANTANA

Keyword(s):

Grain Yield ◽

Block Design ◽

Plant Population ◽

Agronomic Performance ◽

Grain Yields ◽

Cerrado Biome ◽

Cowpea Cultivars ◽

Randomized Block Design ◽

Full Flowering ◽

Pod Length

ABSTRACT The objective of this work was to assess the agronomic performance of cowpea cultivars depending on sowing seasons in the Cerrado biome. Thus, an experiment was conducted in Uberaba, State of Minas Gerais, Brazil, in a complete randomized block design, in a 6x3 factorial arrangement, using six cowpea cultivars (BRS-Itaim, BRS-Guariba, BRS-Potengi, BRS-Cauamé, BRS-Novaera and BRS-Tumucumaque) and three sowing seasons (Dec 14, 2012; Jan 14, 2013; and Feb 14, 2013), with four replications. The interaction between the cultivars and sowing seasons was assessed regarding the number of days for full flowering, number of days for pod maturation, number of trifoliate leaves, height of the first pod -bearing node, pod length, number of pods per plant, final plant population, 100-grain weight and grain yield. The cowpea cultivars sown in December produced the lowest numbers of pods per plant and grains per pod, resulting in the lowest grain yields. The cultivar BRS-Tumucumaque had the highest grain yield in the January sowing. The highest grain yields were found in the February sowing, especially when the cultivars BRS-Itaim (3,439 kg ha-1), BRS-Novaera (3,435 kg ha-1), BRS-Guariba (3,168 kg ha-1) and BRS-Potengi (3,107 kg ha-1) was used.

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Ammonium Glufosinate Associated with Post-Emergence Herbicides in Corn with the cp4-epsps and Pat Genes

Planta Daninha ◽

10.1590/s0100-83582019370100042 ◽

2019 ◽

Vol 37 ◽

Cited By ~ 2

Author(s):

F.H. KRENCHINSKI ◽

V.J.S. CESCO ◽

E.B. CASTRO ◽

C.A. CARBONARI ◽

E.D. VELINI

Keyword(s):

Weed Control ◽

Block Design ◽

Yield Reduction ◽

Genetic Constitution ◽

Ammonium Glufosinate ◽

Randomized Block Design ◽

Visual Damage ◽

Herbicide Mixture ◽

Corn Plants ◽

Cp4 Epsps

ABSTRACT: With the possibility of using ammonium glufosinate in corn, studies on its association with other herbicides are essential. The aim of this study was to assess weed control and herbicide selectivity in association with ammonium glufosinate in corn containing the pat and cp4-epsps genes. The experiment was carried out under field conditions in two sites in a randomized block design with four replications. Treatments consisted of ammonium glufosinate, glyphosate, ammonium glufosinate + glyphosate, ammonium glufosinate + nicosulfuron, ammonium glufosinate + atrazine, ammonium glufosinate + tembotrione, ammonium glufosinate + mesotrione, ammonium glufosinate + carfentrazone ethyl, ammonium glufosinate + bentazon, ammonium glufosinate + 2,4-D, control without weeding, and hand-weeded control. Visual assessments were performed regarding damage, electron transport rate in photosystem II (ETR), ammonia quantification, height, and grain yield of corn plants, as well as weed control at both sites. The application of ammonium glufosinate and its associations did not provide a reduction in productivity when compared to the hand-weeded control. Some treatments presented higher levels of visual damage and ammonia accumulation, but without a yield reduction. Therefore, herbicide mixture with ammonium glufosinate may be an alternative to weed control without damaging corn crop, which presents in its genetic constitution the cp4-epsps and pat genes.

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Weed control in corn and weed sample size for growth evaluations

Planta Daninha ◽

10.1590/s0100-83582014000100006 ◽

2014 ◽

Vol 32 (1) ◽

pp. 51-59 ◽

Cited By ~ 1

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.

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The effect of leaf area reduction on corn plants during the reproduction phase

Revista CERES ◽

10.1590/s0034-737x2011000400002 ◽

2011 ◽

Vol 58 (4) ◽

pp. 413-418 ◽

Cited By ~ 1

Author(s):

Karen Rodrigues de Toledo Alvim ◽

Césio Humberto de Brito ◽

Afonso Maria Brandão ◽

Luiz Savelli Gomes ◽

Maria Teresa Gomes Lopes

Keyword(s):

Grain Yield ◽

Leaf Area ◽

Block Design ◽

Plant Leaves ◽

Spike Density ◽

Area Reduction ◽

Randomized Block Design ◽

Minas Gerais State ◽

Corn Plants ◽

Root Resistance

Reduction in leaf area in corn plants during reproduction changes physiological metabolism and consequently the accumulation of dry matter in grains. The aim of this work was to study changes in agronomic characteristics caused by defoliation in corn during the reproduction phase. The experiment was carried out in Uberlândia, Minas Gerais state, in the agricultural year 2007/2008. The experiment was arranged in a randomized block design, consisting of seven treatments: control without defoliation, removal of two apical leaves, removal of four apical leaves, removal of all leaves above spike, removal of four intermediate leaves, removal of all leaves below spike, and removal of all plant leaves, with five repetitions. The genotype used for the evaluations was hybrid NB 7376. Defoliation was carried out when plants were at the growth stage R2. The variables assessed were: yield, density of spikes and corncobs, root resistance and stem integrity. When all leaves above the spike were removed, grain yield was reduced by 20%. Corncob density, stem integrity and root resistance to uprooting were also affected. Spike density was only affected when all plant leaves were removed. The leaf area remaining physiologically active above the spike was found to be most efficient in terms of grain yield.

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Agronomic Performance of Soybean With Seeds Treated With an Algae Extract Base Biostimulant

Journal of Agricultural Science ◽

10.5539/jas.v13n1p147 ◽

2020 ◽

Vol 13 (1) ◽

pp. 147

Author(s):

Gabriel Bressiani Melo ◽

Alessandro Guerra da Silva ◽

Adriano Perin ◽

Guilherme Braga Pereira Braz ◽

Christiano Lima Lobo de Andrade

Keyword(s):

Grain Yield ◽

Block Design ◽

Natural Compounds ◽

Soybean Seeds ◽

Agronomic Performance ◽

Grain Yields ◽

Beneficial Effects ◽

Agronomic Characteristics ◽

Organic Components ◽

Randomized Block Design

The use of biostimulants in the treatment of soybean seeds can provide beneficial effects on the crop due to the synergism between the organic components present in products from natural compounds. Due to the scarcity of results of research on biostimulants in the treatment of soybean seeds, the objective of this study was to evaluate the effects of doses of a biostimulant in the treatment of seeds, on agronomic characteristics, productivity components and profitability of soybean culture. Therefore, two experiments were carried out in the field in the 2016/17 and 2017/18 harvests, using a randomized block design with six replications and four treatments referring to doses of 0.00; 0.05; 0.10; and 0.15 L 100 kg seeds-1. The agronomic characteristics of soybeans, grain yield and profitability of using the biostimulant were evaluated. From the obtained results, it can be seen that the dose of 0.15 L 100 kg seeds-1 provided greater profitability in both harvests. In addition, doses above 0.12 L 100 kg seed-1 provide higher grain yields and a higher grain mass, in addition to other productivity components.

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Weed dynamics, weed control efficiency and yield of aerobic rice as influenced by different weed management practices in eastern U.P.

Journal of Environmental Biology ◽

10.22438/jeb/41/6/si-264 ◽

2020 ◽

Vol 41 (6) ◽

pp. 1735-1740

Author(s):

R.K. Parihar ◽

◽

V.K. Srivastava ◽

S. Kumar ◽

V. Kumar ◽

...

Keyword(s):

Grain Yield ◽

Weed Control ◽

Weed Management ◽

Management Practices ◽

Block Design ◽

Aerobic Rice ◽

Control Efficiency ◽

Randomized Block Design ◽

Weed Control Efficiency ◽

Broad Leaf

Aim: To identify the best sequence of pre- and post-emergence herbicides for achieving better weed control efficiency in aerobic rice. Methodology: A field experiment was conducted in Randomized Block Design with eleven treatment combinations, replicated thrice.? The dominant weeds in field were C. dactylon, E. colona and E. crusgalli among grasses, C. rotundus, C. difformis and F. maliaceae among sedges and C. axillaris and P. niruri among broad-leaf weeds. Treatments consisting sequential application of two pre-emergence application [Pendimethalin (30 EC) @ 1.00 kg a.i. ha-1; Butachlor (50 EC) @ 1.5 kg a.i. ha-1] followed by three post emergence herbicides [Bispyribac-Na (10% SC) @ 35 g a.i. ha-1; 2, 4-D Na salt (80 WP) @ 0.06 kg a.i. ha-1; Almix (CME + MSM ) (20 WP) @ 40 g a.i. ha-1] and straw mulching @ 4 t ha-1;? Mechanical weeding at 20 and 45 DAS, weed free and unweeded check.? Results: Among herbicidal treatments, pre-emergence application of pendimethalin at 3-4 DAS fb Bispyribac-Na at 15-20 DAS as post-emergence was most effective in minimizing weed density (4.81 m-2), biomass (6.20 g m-2), weed index (1.11%) and in enhancing the weed control efficiency (84.50%), grain yield (3.68 t ha-1) and straw yield (4.87 t ha-1) over rest of the treatments. Interpretation: Sequential application of pendimethalin at 3-4 DAS fb bispyribac-Na at 15-20 DAS is prominent in enhancing herbicide efficacy and reducing weed flora abundance resulting in higher weed control efficiency and grain yield due to their broad spectrum weed control.

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Effect of the use of pre- and post-emergence herbicides on nodulation and production of cowpea (Vigna unguiculata L.) in the Amazonian savannah

Agronomía Colombiana ◽

10.15446/agron.colomb.v38n2.82196 ◽

2020 ◽

Vol 38 (2) ◽

pp. 280-286

Author(s):

Anna Bárbara De Souza Cruz ◽

José de Anchieta Alves de Albuquerque ◽

Paulo Roberto Ribeiro Rocha ◽

Leandro Torres de Souza ◽

Diego Lima de Souza Cruz ◽

...

Keyword(s):

Grain Yield ◽

Root System ◽

Weed Control ◽

Dry Matter ◽

System Development ◽

Control Strategies ◽

Control Measure ◽

Block Design ◽

Root System Development ◽

Randomized Block Design

As a control measure against weeds, the use of herbicides is an effective and inexpensive alternative. However, there are no products recommended for the cultivation of cowpea in Brazil, making it necessary to search for alternative solutions. The objective of this study was to evaluate the effect of herbicides applied in the pre- and post-emergence on cowpea nodulation and production under conditions of the Amazonian savannah. Two experiments were carried out in a randomized block design with four replicates, using the cowpea cultivar BRS Aracê subjected to the pre-emergence herbicides: Metribuzin, Sulfentrazone, Smetolachlor, Pendimethalin, Oxadiazon, Alachlor, Metribuzin + Pendimethalin, Metribuzin + Alachlor and Quizalofop-p-ethyl, Bentazon, Fomesafen, Imazethapyr, Imazamox + Bentazon, Quizalofop-p-ethyl + Imazethapyr, Quizalofop-p-ethyl + Imazamox and Quizalofop-p-ethyl + Bentazon, and post-emergence herbicides: Quizalofop-p-ethyl, Bentazon, Fomesafen, Imazethapyr, Imazamox + Bentazon, Quizalofop-p-ethyl + Imazethapyr, Quizalofop-p-ethyl + Imazamox, and Quizalofop-p-ethyl + Bentazon. The number of nodules in each plant, the dry matter of nodules, dry matter of roots and the grain yield were evaluated. According to the results obtained, the management of weeds in pre- or post-emergence according to the herbicide used affects the nodulation and productivity of cowpea under the conditions of the Amazonian savannah. The herbicides Metribuzin in preemergence,and Fomesafen and the mixture of Quizalofop-pethyl + Imazethapyr in post-emergence are not recommended for weed control in cowpea. The application of Oxadiazon, Alachlor, and Pendimethalin in pre-emergence can be considered interesting because they do not inhibit the development of the root system or the nodulation of cowpea which provides agreater grain yield. Regarding weed control strategies at postemergence, the application of the herbicide Imazethapyr and the combination of the herbicides quizalofop-p-ethyl + imazamox, Quizalofop-p-ethyl + Bentazon and Imazamox + Bentazon allow satisfactory levels of grain yield, root system development and nodulation of cowpea.

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Corn and soybean yields as affected by cover crops and herbicide timing under no-tillage system

Planta Daninha ◽

10.1590/s0100-83582013000400020 ◽

2013 ◽

Vol 31 (4) ◽

pp. 939-946

Author(s):

P. Oliveira ◽

A.S. Nascente ◽

J. Kluthcouski ◽

T.A.P. Castro

Keyword(s):

Grain Yield ◽

Common Bean ◽

Cover Crops ◽

Cover Crop ◽

Block Design ◽

No Tillage ◽

Brachiaria Brizantha ◽

Grain Yields ◽

Randomized Block Design ◽

Tillage System

To achieve better results in the no-tillage system (NTS), it is important to properly manage the cover crop prior to planting by using herbicides, usually glyphosate. The effect of glyphosate on plant coverage is slow, and plants take a few days to die completely. Thus, when applying the herbicide on the same day of planting soybean or corn, cover crops are still alive and standing, causing initial shading on seedlings of the crop and delaying its establishment. Therefore, this study aimed to evaluate the effect of distinct cover crops and their timing of desiccation prior to planting soybean or corn, on crop yield and yield components. Two experiments were installed, one for soybean and another for corn. Each experiment consisted in combining three cover crops (Brachiaria brizantha, common bean or millet) chemically desiccated at two timings before planting the crop (15 or 0 days before planting) under no-tillage system (NTS). Experiments were installed in a completely randomized block design with five replications. Brachiaria brizantha produced the highest amount of biomass; common bean and millet as cover crops allowed higher soybean grain yields; herbicide application under common bean, millet and Brachiaria brizantha 15 days before planting soybean allowed higher crop grain yields; desiccation timing of common bean did not affect corn grain yield; Brachiaria brizantha should be desiccated 15 days before planting corn to allow maximum grain yield; when millet was used as a cover crop, glyphosate application at planting of corn allowed the highest grain yield.

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Influence of corn sowing density and gliricidia intercropping on weed control

Planta Daninha ◽

10.1590/s0100-83582010000200006 ◽

2010 ◽

Vol 28 (2) ◽

pp. 271-279 ◽

Cited By ~ 3

Author(s):

P.S.L. Silva ◽

A.D. Souza ◽

V.F.S. Paula ◽

F.H.T. Oliveira ◽

K.M.B. Silva

Keyword(s):

Grain Yield ◽

Weed Control ◽

Block Design ◽

Seeding Density ◽

Corn Hybrids ◽

Weed Growth ◽

Randomized Block Design ◽

Yield Values

There is interest in the identification of the best seeding density for new corn hybrids and on reduced use of herbicides for weed control. The objective of this study was to evaluate the effects of seeding density (30, 50, 70, and 90 thousand plants ha-1) and weed control on green ear yield and grain yield in corn cultivar AG 1051. A completely randomized block design was adopted with split-plots (seeding densities assigned to plots) and ten replicates. Weed control was achieved by means of two hoeings and by planting corn intercropped with gliricidia (between corn rows, in pits spaced 0.3 m apart). A "no weeding"treatment was included as well. Increased seeding density increased the total number and weight of marketable green ears and decreased the biomass of both weeds and gliricidia. In non-weeded, intercropped and hoed plots, the maximum grain yield values achieved as seeding density increased were 7,881, 7,021, and 9,213 kg ha-1, respectively, obtained with populations of 67 thousand, 74 thousand, and 67 thousand plants per hectare, respectively. Intercropping did not control weeds (26 species) and provided weed growth, green ear yield, and grain yield (at the lowest densities) similar to those obtained without hoeing, except for total number of green ears, in which no influence of weed control was observed. At densities of 70 thousand and 90 thousand plants per hectare, grain yield with two hoeings was not different from yield values obtained without weeding or in the treatment intercropped with gliricidia, respectively, indicating that increased corn seeding density as well as gliricidiamay help to control weeds.

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Growth and yield of corn grain and green ear in competition with weeds

Planta Daninha ◽

10.1590/s0100-83582009000500008 ◽

2009 ◽

Vol 27 (spe) ◽

pp. 947-955 ◽

Cited By ~ 8

Author(s):

P.S.L Silva ◽

A.P.A.B Damasceno ◽

K.M.B Silva ◽

O.F Oliveira ◽

R.C.F Queiroga

Keyword(s):

Weed Control ◽

Block Design ◽

Statistical Analyses ◽

Growth And Yield ◽

Yield Reduction ◽

Weed Species ◽

Randomized Block Design ◽

Random Block ◽

Block Experiment ◽

Ground Part

Studies on plant growth are interesting because they provide explanations for the factors that influence yield in various crops. The objective of this work was to evaluate growth and yield in corn cultivar AG1051, when in competition with weeds. Cultivar AG 1051 was submitted to two groups of treatments: weed control, and sampling periods for dry biomass evaluation. The weed control treatments consisted of hoeing (two hoeings performed at 20 and 40 days after sowing) and no hoeing. Sampling periods consisted of collecting the above-ground part and roots of corn every fifteen days, until 105 days after sowing (DAS); the first sampling was performed 30 DAS. A completely randomized block design with ten replicates was used. For the characteristics evaluated in a single season, statistical analyses were carried out as a random block experiment. For the characteristics evaluated in several periods, statistical analyses were carried out as random blocks with split-plots (weed control assigned to plots). Fourteen weed species, unevenly distributed throughout the experimental area, were the most important. The growth observed for the above-ground part and root system of corn was 30% smaller in the non-hoed plots, compared to the hoed plots. Lack of weed control increased dry matter of the above-ground part of the weeds and reduced the number of unhusked and husked marketable green ears by 23% and 49%, respectively. Grain yield reduction caused by lack of weed control reached 38%.

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