scholarly journals Chemical control of signalgrass in alfalfa crops

2017 ◽  
Vol 38 (6) ◽  
pp. 3695 ◽  
Author(s):  
Renan Coelho Dias ◽  
Márcia Vitória Santos ◽  
Fabiana Lopes Ramos de Oliveira ◽  
Evander Alves Ferreira ◽  
José Barbosa dos Santos ◽  
...  
Keyword(s):  
Dry Matter ◽  
Physiological Stress ◽  
Block Design ◽  
Photosynthetic Apparatus ◽  
Herbicide Application ◽  
Brachiaria Decumbens ◽  
Physiological Variables ◽  
Randomized Block Design ◽  
Forage Species ◽  
Tiller Density

The use of herbicides to control grass in Medicago sativa (alfalfa) pastures is still incipient. Therefore, the objective of this study was to evaluate the efficiency of fluazifop-p-butyl in the control of Brachiaria decumbens (signalgrass) in alfalfa. Thus, randomized block design was used, with seven doses of fluazifop-p-butyl (0, 25, 50, 100, 200, 300, 400 g ha-1), and four replications. Herbicide application was performed when the plants had about 20 cm height. Chlorophyll fluorescence, control of signalgrass and alfalfa toxicity were evaluated at 7, 15 e 30 days after application (DAA) and, at 45 DAA and 45 days after cut (DAC), both species were cut and tiller density, as well as branches and dry matter of forage species, were determined. Fluazifop-p-butyl does not affect the integrity of the photosynthetic apparatus of alfalfa plants, due to high tolerance to this mechanism of action presented by dicotyledonous species. However, signalgrass had physiological variables negatively affected by the herbicide, indicating the presence of physiological stress, even at the lowest doses of the product. The dose of 50 g ha-1 of fluazifop-p-butyl is effective in controlling signalgrass, without causing physiological and growth damage in alfalfa plants.

scholarly journals Influence of glyphosate underdoses on the suppression of Panicum maximum cultivars

2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Suzete Fernandes Lima ◽  
Leandro Spíndola Pereira ◽  
Gustavo Dorneles Sousa ◽  
Simonny Araújo Vasconcelo ◽  
Adriano Jakelaitis ◽  
...  
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Block Design ◽  
Treatment Plant ◽  
Dry Matter Production ◽  
Panicum Maximum ◽  
Initial Growth ◽  
Randomized Block Design ◽  
Matter Production ◽  
Forage Species

ABSTRACT: The use of herbicide underdoses allows minimizing the competition of grasses on annual crops, enabling simultaneous cultivation. In this context, the objective of this study was to investigate glyphosate underdoses on the suppression of the initial growth of three Panicum maximum cultivars aiming at the integrated cultivation, in addition to the effects of forage species on the incidence and development of weeds. Three field experiments were conducted. The experimental design was a randomized block design with four replications and eight treatments consisting of increasing glyphosate doses (0, 54, 108, 270, 378, 540, 756, and 1,080 g a.e. ha−1). An atrazine dose of 1,200 g a.i. ha−1 was added to each treatment. Plant phytotoxicity assessments were performed at 7, 14, 21, and 28 days after application. At 80 and 125 days after sowing, the assessments of total dry matter production, leaf dry matter, stem dry matter, and leaf to stem ratio were carried out, in addition to density and dry matter production of weed community. Glyphosate underdoses below 215, 65, and 90 g a.e. ha-1 have a potential to be investigated aiming at the management of P. maximum cv. Atlas, P. maximum cv. Mombasa, and P. maximum cv. Tanzania under intercropping. The three forage species are effective in suppressing weeds.

scholarly journals HERBICIDE SELECTIVITY TO SIGNAL GRASS AND CONGO GRASS

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
A.H.C. ANÉSIO ◽  
M.V. SANTOS ◽  
R.R. SILVEIRA ◽  
E.A. FERREIRA ◽  
T.G.S. BRAZ ◽  
...  
Keyword(s):  
Electron Transport Chain ◽  
Block Design ◽  
Herbicide Application ◽  
Brachiaria Decumbens ◽  
Brachiaria Ruziziensis ◽  
Randomized Block Design ◽  
Transport Chain ◽  
Minas Gerais State ◽  
Signal Grass ◽  
Control Samples

ABSTRACT This study was conducted in order to evaluate the selectivity of signal grass and congo grass, submitted to post-emergence herbicide application. The experiment was conducted under greenhouse conditions, in Diamantina, Minas Gerais state, and it was arranged in a randomized block design, with five replications. Treatments were set in factor scheme (8 x 2) + 2. Eight herbicides (nicosulfuron; clomazone; glyphosate; fluazifop-p-butyl + fomesafen; lactofen; fomesafen; fluazifop-p-butyl and mesotrione) were applied in doses recommended by the manufacturer on two fodder species: Brachiaria decumbens cv. Basilisk (signal grass) and Brachiaria ruziziensis (congo grass); in addition, there were two control samples without herbicide application, for a total of 18 treatments. The evaluated herbicides showed less intoxication on signal grass when compared to congo grass. Nicosulfuron and glyphosate promoted higher intoxication on both species when compared to the other herbicides. Glyphosate, fluazifop-p-butyl + fomesafen, fluazifop-p-butyl, mesotrione and nicosulfuron affected the ratio variable / maximum fluorescence (Fv/Fm) in both species, indicating an effect provided by these herbicides on the electron transport chain. Results demonstrated that signal grass and congo grass have higher susceptibility to glyphosate, fluazifop-p-butyl + fomesafen, fluazifop-p-butyl, mesotrione and nicosulfuron. congo grass shows higher susceptibility to the studied herbicides when compared to signal grass.

scholarly journals Management Of Commelina benghalensis with Saflufenacil in Shaded Environments

2019 ◽  
Vol 37 ◽  
Author(s):  
A. SANTOS JUNIOR ◽  
F.C.L. FREITAS ◽  
I.T. SANTOS ◽  
D.C. SILVA ◽  
G.P. PAIXÃO ◽  
...  
Keyword(s):  
Experimental Design ◽  
Dry Matter ◽  
Block Design ◽  
Mechanisms Of Action ◽  
Dry Matter Accumulation ◽  
Herbicide Application ◽  
Commelina Benghalensis ◽  
Randomized Block Design ◽  
Eucalyptus Plantations ◽  
Cultivation Environment

ABSTRACT: The repetitive use of glyphosate in the control of weeds in eucalyptus plantations has selected tolerant species such as Commelina benghalensis. Therefore, the use of herbicides of other mechanisms of action, such as saflufenacil, in rotation or combination with glyphosate, is necessary to reduce damages caused by C. benghalensis, whose sensitivity to herbicides can be influenced by the shading caused by the eucalyptus crop. This study aimed to assess the efficiency of saflufenacil in the management of C. benghalensis at different shading levels. Three experiments were carried out regarding a certain shading level (cultivation environment with 0, 40, and 55% shade). The experimental design was a randomized block design with five herbicide doses (0, 24.5, 49, 73.5, and 98 g ha-1 of saflufenacil) and four replications. At 28 days after herbicide application, the percentage of control and shoot dry matter were assessed, as well as the biomass allocation to leaves, stems, and roots of C. benghalensis. Plants cultivated at 0% shade presented a higher dry matter accumulation and a better distribution of biomass in leaves, stem, and roots, contributing with the increased tolerance to saflufenacil and not being controlled with effectiveness under the assessed doses. As shading was increased, plants of C. benghalensis allocated most of their biomass to the shoot, especially leaves, reducing their reserve structures and increasing the contact area with the herbicide, making them more susceptible to saflufenacil.

scholarly journals CHLOROPHYLL FLUORESCENCE IN Brachiaria decumbens AND Brachiaria ruziziensis SUBMITTED TO HERBICIDES

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
R.R. SILVEIRA ◽  
M.V. SANTOS ◽  
E.A. FERREIRA ◽  
J.B. SANTOS ◽  
L.D. SILVA
Keyword(s):  
Chlorophyll Fluorescence ◽  
Physiological Response ◽  
Physiological Responses ◽  
Photosynthetic Apparatus ◽  
Herbicide Application ◽  
Brachiaria Decumbens ◽  
Brachiaria Ruziziensis ◽  
Significant Difference ◽  
Forage Species ◽  
Different Doses

ABSTRACT Different doses of herbicides can promote a differentiated physiological response in grasses of the same genus. This study has been proposed in order to evaluate physiological responses of B. ruziziensis and B. decumbens submitted to glyphosate and fluazifop-p-butyl. Treatments were distributed in a 2 x 6 factorial design with five repetitions, being two grasses: B. decumbens cv. Basilisk and B. ruziziensis with six doses of herbicides: 0.00; 0.25; 0.50; 1.00; 1.5 and 2.00 times the commercial dose recommended by manufacturers. At 7, 15, 21, and 30 days after herbicide application (DAA) chlorophyll luminous energy uptake efficiency was evaluated. Plants subjected to glyphosate at 7 days after application (DAA) showed minimum fluorescence of 270 and 245 quantum-1 electrons to B. ruziziensis and B. decumbens, respectively, levels increased by 350% when compared to the control, and at 15 DAA the treated plants have completely dried up. At 15 DAA, both forage species submitted to the fluazifop-p-butyl showed a 25% reduction in Fv/Fm ratio compared with the control and there was no significant difference between the lowest and highest doses applied. B. ruziziensis and B. decumbens are more sensitive to glyphosate than fluazifop-p-butyl. Regarding fluazifop-p-butyl, B. ruziziensis was more sensitive than B. decumbens and at 45 days after cutting B. decumbens plants submitted to doses up to 100 g ha-1 were able to regenerate their photosynthetic apparatus.

scholarly journals Leaves per tiller as the criterion to determine optimum defoliation frequency in pastures of Brachiaria decumbens

2020 ◽  
Vol 73 (2) ◽  
pp. 9151-9163
Author(s):  
Diana Leidy Manrique Luna ◽  
Juan Evangelista Carulla Fornaguera
Keyword(s):  
Repeated Measures ◽  
Nutritional Quality ◽  
Crude Protein ◽  
Dry Matter ◽  
Block Design ◽  
Dry Matter Accumulation ◽  
Brachiaria Decumbens ◽  
Randomized Block Design ◽  
Number Of Leaves ◽  
Defoliation Frequency

Two studies were performed to establish the best defoliation frequency in Brachiaria decumbens using the number of leaves per tiller as a criterion. In the first study, 3,500 tillers with 2, 3, 4, 5, or 6 leaves were collected in 10 farms. The number of green, senescent, and dead leaves was counted. A pooled sample of tillers by each farm with a given number of leaves was analyzed for nutritional quality; a complete randomized block design was used for this study. In a second study, it was implemented a complete ramdomized design with repeated measures over time (2 defoliations), and the effect of defoliating B. decumbens at 3, 4, or 5 leaves per tiller on its growth, dry matter yield, and nutritional quality were evaluated. In the first study, all leaves remained green until the tiller had 3 leaves. At the fourth leaf, few tillers (2.3%) had senescent leaves, but at 6 leaves, most tillers had senescent (40.6%) or dead (24.4%) leaves. Crude protein and digestibility decreased as the number of leaves in a tiller increased (P<0.001). In the second study, the rate of dry matter accumulation was the highest for plots defoliated at 4 leaves (P<0.05). Green stems (43.9%) represented a larger proportion of dry matter than green leaves (31.4%), and their proportions were similar among treatments. Crude protein and digestibility of stems decreased as the number of leaves per tiller increased (P<0.001), but the quality of leaves was similar. These findings suggest that these pastures should be defoliated at 4 leaves per tiller.

scholarly journals Nitrogen topdressing and application ways of fluazifop-p-butyl + fomesafen in weed control and agronomic performance of common bean

2015 ◽  
Vol 87 (4) ◽  
pp. 2301-2307 ◽  
Author(s):  
MATHEUS G. SILVA ◽  
ORIVALDO ARF ◽  
PAULO E. TEODORO
Keyword(s):  
Common Bean ◽  
Weed Control ◽  
Yield Components ◽  
Dry Matter ◽  
Block Design ◽  
Agronomic Performance ◽  
Randomized Block Design ◽  
Bean Yield ◽  
Leaf N Content ◽  
Leaf N

ABSTRACT The objective of this study was to investigate the effect of interaction between nitrogen topdressing and different application ways (active ingredients) a.i. fluazifop-p-butyl + fomesafen in weed control and agronomic performance of common bean. The experiment was conducted during winter 2003 in Selvíria/MS. The experimental design used was a randomized block design with four replications in a factorial scheme 2x7. The first factor was composed by the absence or presence of nitrogen topdressing, while the second factor consisted of different application ways of fluazifop-p-butyl + fomesafen. The following variables were measured: leaf N content, dry matter of plants, yield components (number of pods plant-1, number of grains plant-1, the average number of grains pod-1 and mass of 100 grains), grain yield, phytotoxicity and weed control percentage. The nitrogen topdressing with 75 kg ha-1provided higher dry matter of plants, higher weed control and higher common bean yield of irrigated winter. In the absence of nitrogen topdressing in the application of urea before or together to fluazifop-p-butyl + fomesafen increased their effectiveness in controlling weeds without interference in the agronomic performance of common bean.

scholarly journals Nitrogen and potassium supply and the morphogenic and productive characteristics of marandu palisadegrass

2010 ◽  
Vol 39 (8) ◽  
pp. 1666-1675 ◽  
Author(s):  
Marcio Mahmoud Megda ◽  
Francisco Antonio Monteiro
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
System Development ◽  
Block Design ◽  
Dry Mass ◽  
Dry Matter Production ◽  
Root System Development ◽  
Randomized Block Design ◽  
Matter Production ◽  
Specific Length

The objective of this work was to study morphogenic characteristics, and dry matter production of roots and shoots of marandu palisadegrass (Brachiaria brizantha cv. Marandu) submitted to combinations of nitrogen and potassium, in a nutritive solution, employing silica as substrate. The experiment was carried out in a greenhouse during the summer. It was used a 5² fractionated factorial scheme with 13 combinations of nitrogen and potassium, which were distributed in a randomized block design, with four replications. The nitrogen × potassium interaction was significant for the number of tillers and leaves, for leaf area, for shoots and root section dry mass, for total length and surface and specific length and surface in the roots. Production of aerial part dry mass positively correlated with the number of tillers and leaves and grass leaf area. Nitrogen rates modulated the root system development, and the root specific length and surface decreased when high rates of nitrogen and potassium were supllied. Nitrogen and potassium influence Marandu palisadegrass morphogenic characteristics, which are determinant for grass dry matter production.

scholarly journals DIFFERENT STABILITY METHODS FOR CULTIVAR RECOMMENDATION IN ELEPHANT-GRASS FOR ENERGY PURPOSES IN BRAZIL

CERNE ◽  
2017 ◽  
Vol 23 (4) ◽  
pp. 507-515 ◽  
Author(s):  
Veronica Brito da Silva ◽  
Rogerio Figueiredo Daher ◽  
Bruna Rafaela da Silva Menezes ◽  
Maria Lorraine Fonseca Oliveira ◽  
Maria do Socorro Bezerra Araújo ◽  
...  
Keyword(s):  
Energy Production ◽  
Dry Matter ◽  
Block Design ◽  
Dry Matter Yield ◽  
Elephant Grass ◽  
Randomized Block Design ◽  
Matter Production ◽  
Breeding Programmes ◽  
The Stability ◽  
Non Parametric

ABSTRACT The elephant-grass undergoes successive cutting and periodical evaluations that it possible to identify clones with high stability for dry matter production, which can be used for energy production. The present study was carried out to evaluate stability dry matter yield for different parametric and non-parametric methods in elephant grass genotypes for biomass production undergoes successive cutting in the agroclimatic conditions of the Norte Fluminense (RJ, Brazil). The variable measured in the 40 genotypes was dry matter yield (DMY) at 2009, 2010 and 2011 in a field study designed as randomized block design with two replicates. Each sample was grown in different environment condition. The stability methods tested were the Yates and Cochran’s, Plaisted and Peterson’s, Wricke’s ecovalence, Annicchiarico’s, Lin and Binns’ and Kang and Phan’s. Results indicated that cutting (E) and genotypes (G) influenced significantly on the performance of dry matter yield. The non-parametric stability methods were effective for the evaluation of stability in dry matter yield. Genotypes Mercker, Pinda-México, Mercker 86-México, Guaçu/IZ, Mercker Pinda, P-241-Piracicaba and Cubano Pinda were stable stability dry matter yield. Hence, there are genotypes may be exploited in future breeding programmes in order to improve productivity of upland elephant grass over environment.

Effect of intraruminal infusion of urea on the response in voluntary food intake by sheep

1985 ◽  
Vol 36 (3) ◽  
pp. 483 ◽  
Author(s):  
JK Egan ◽  
PT Doyle
Keyword(s):  
Organic Matter ◽  
Food Intake ◽  
Dry Matter ◽  
Block Design ◽  
Ammonia Nitrogen ◽  
Dry Matter Intake ◽  
Plant Cell Walls ◽  
Randomized Block Design ◽  
Ad Libitum ◽  
Ad Libitum Intake

Six mature Merino sheep received three treatments in a randomized block design experiment. The treatments were: chopped oaten hay diet at 90% of ad libitum intake without urea (L); the ciet offered at the same level as for L with urea infused into the rumen at 11.5 g kg-1 dry matter intake (LU); and the diet offered at 90% of the ad libitum intake achieved with urea infused at 11.5 g kg-1 dry matter intake (HU). Sheep given HU consumed 37% more (P < 0.01) organic matter (OM) than those fed L or LU, but the apparent digestibility of OM did not vary (59.2-61.8%) between treatments. The addit onal food consumption was associated with c. 20% increase (P < 0.05) in the weight of OM in the reticulorumen and significantly higher (by 10-35%; P < 0.05) fractional outflow rates of most dietary and microbial constituents of digesta. The fractional digestion rate of potentially digestible plant cell walls was not affected by urea, but the flow of microbial non-ammonia nitrogen from the abomasum was enhanced (L, 7.0; LU, 8.2; HU, 12.5 g day-1; P < 0.05). The results of this study suggest that the stimulatory effect of urea upon food intake was associated with the provision of additional microbial protein for digestion in the intestines, rather than changes in the rate or extent of organic matter fermentation in the reticulorumen.

scholarly journals Evaluation of different corn textures in dry grain or silage forms for piglets from 7 to 15 kg

2009 ◽  
Vol 38 (9) ◽  
pp. 1757-1761
Author(s):  
José Vieira Neto ◽  
Vinícius de Souza Cantarelli ◽  
Elias Tadeu Fialho ◽  
Márcio Gilberto Zangeronimo ◽  
Nikolas de Oliveira Amaral ◽  
...  
Keyword(s):  
Dry Matter ◽  
Block Design ◽  
Metabolizable Energy ◽  
Experimental Unit ◽  
Feed Conversion ◽  
Initial Weight ◽  
Large White ◽  
Randomized Block Design ◽  
Independent Form ◽  
Ensilage Corn

The objective of this study was to evaluate different textures and storage forms of corn in piglet diets. Two experiments were conducted, one of which tested digestibility of nutrients and the other diet performance. In the digestibility trial, 24 crossbred (Landrace X Large White) barrows with an initial weight of 18.7 ± 1.5 kg were used. They were kept in metabolic cages in a randomized block design using the factorial arrangement 2 X 2 (type of corn - dent and flint X type of storage - moist grain silage and dry grain) and six replicates, with one animal as the experimental unit. The values of metabolizable energy (ME) obtained were 3841 kcal of ME/kg of dry matter (DM) from dry corn, 3912 kcal of ME/kg of DM from moist corn, 4022 kcal of DM from ensiled dry corn and 3928 kcal of ME/kg of DM from ensiled humidity corn. The ensilage process increases the digestibility coefficient of dry matter and crude protein and increases the digestible energy of the diets, independent of the process form. The type of corn did not influence these variables. In the performance trial, 60 barrows (initial weight of 6.5 ± 1.5 kg) of the same stock were used during 28 days of post-weaning distributed in the same experimental design, with five replicates and three animals as the experimental unit. The treatments did not influence the daily weigh gain or the daily feed intake. The dentate corn and the ensilage process decreased the feed conversion of the independent form (no significant interaction). The substitution of dry for ensilage corn increased the digestibility of the nutrients in the diets and the feed conversion of the piglets from 7 to 15 kg. Dentate corn promotes best feed conversion in this phase.

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