Morphogenetic and structural characteristics of gamba grass subjected to nitrogen fertilization and different defoliation intensities

T This study aimed to evaluate the morphogenetic, structural, and productive characteristics of Andropogon gayanus cv. ‘Planaltina’ subjected to different nitrogen fertilization levels and defoliation intensities. The experiment was done in a completely randomized design with a factorial arrangement of six nitrogen doses (0, 100, 200, 300, 400, and 500 kg N ha-1) and two defoliation intensities (15 and 30 cm). The production and structure data were grouped into rainy and dry periods, while morphogenesis data were compared only among different fertilization and defoliation intensities. The total dry forage biomass (TDFB), dry mass of leaves (DML), dry mass of stems (DMS), and dead forage dry mass (DFDM) were then determined. In addition to these variables, the morphogenetic characteristics of the plants and the numbers of tillers alive and dead were evaluated. There was no interaction (P>0.05) between the effects of nitrogen fertilization doses and the intensity of defoliation on TDFB, DML, DMS, and DFDM in both of the evaluated phases (rainy and dry). It was also observed that the rates of leaf elongation, leaf appearance, and leaf blade elongation increased with nitrogen fertilization. On the other hand, the culm elongation rate and phyllochron decreased as the dose applied increased. The defoliation intensity did not influence (P>0.05) the morphogenetic characteristics examined, nor did it affect the senescence rate of nitrogen in leaves and number of live leaves per tiller. The number of dead tillers increased linearly during the rainy period. Based on these results, to improve the efficiency of production of gamba grass it is recommended that it be managed with a defoliation intensity of 30 cm and nitrogen fertilization of 286.52 kg N ha-1 year-1.

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Ecophysiology of Andropogon grass subjected to different cutting frequencies and intensities

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v24n9p610-615 ◽

2020 ◽

Vol 24 (9) ◽

pp. 610-615

Author(s):

Juliana R. L. Lima ◽

Rosane C. Rodrigues ◽

Giovanne O. C. Sousa ◽

Clésio dos S. Costa ◽

Henrique N. Parente ◽

...

Keyword(s):

Structural Characteristics ◽

Stem Elongation ◽

Dry Mass ◽

Forage Production ◽

Leaf Elongation ◽

Randomized Design ◽

Andropogon Gayanus ◽

Demographic Patterns ◽

Cutting Height ◽

Cutting Intensity

ABSTRACT The objective of this study was to evaluate the morphogenic and structural characteristics, and demographic patterns of Andropogon gayanus subjected to different cutting frequencies and intensities. A completely randomized design was adopted in a 3 × 2 factorial arrangement, corresponding to three cutting heights (50, 70, and 90 cm), and two cutting intensities (50 and 70%) with four repetitions, totaling 24 plots of 7.50 × 6.25 m. For morphogenesis, there was no interaction effect (P ≤ 0.05) of treatments on stem elongation rate, leaf appearance rate, and phyllochron rate. The highest rate of leaf elongation was observed at a height of 90 cm and cut intensity of 50%, with 1.69 and 0.84 cm tiller-1 d-1 of leaf elongation at heights of 50 and 70 cm, respectively. For forage production, there was no interaction (p > 0.05) between cutting intensity and cutting height. When the pasture was managed to a cutting height of 90 cm, there was a greater increase in dry leaf mass, stalk dry mass, dead forage dry mass, and total dry forage mass, which was 50.89% and 53.29% higher than pasture heights of 50 and 70 cm, respectively. There was no interaction between factors on demographic characteristics (p > 0.05). A cutting height of 70 cm with a cutting intensity of 50% is recommended when handling this grass.

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Morphogenic and structural characteristics and chemical composition of grass aruana, submitted to nitrogen fertilization

Semina Ciências Agrárias ◽

10.5433/1679-0359.2019v40n6supl2p3167 ◽

2019 ◽

Vol 40 (6Supl2) ◽

pp. 3167 ◽

Cited By ~ 1

Author(s):

Alice Mariana Hupp Sacramento ◽

Olga Cedro de Menezes ◽

Tarcísio Marques Barros ◽

Diego Novais Pinheiro ◽

Soraya Maria Palma Luz Jaeger ◽

...

Keyword(s):

Chemical Composition ◽

Nitrogen Fertilization ◽

Structural Characteristics ◽

Block Design ◽

Dry Mass ◽

Leaf Length ◽

Panicum Maximum ◽

Nitrogen Levels ◽

Randomized Block Design ◽

Leaf Appearance

This study aimed at evaluating the morphogenic and structural characteristics of Panicum maximum Jacq. cv. Aruana, as well as its chemical composition after submitting it to different nitrogen levels. The experiment was performed by adopting a randomized block design which included four treatments (0, 75, 150 and 225 kg ha-1 of N) and three replications, in 100 m2 plots. Twice a week, for the 63 days of regrowth, the morphogenic characteristics were determined and estimated, after which the chemical composition was assessed. The aruana grass revealed a quadratic and positive response to the nitrogen fertilization, and showed a remarkable rise in the elongation rates, leaf appearance and senescence, besides the number of live leaves per tiller and final leaf length. However, the nitrogen fertilization reduced the phyllochron and leaf life in the aruana grass, implying the direct effect of nitrogen on the flow of tissues. A quadratic and positive effect of the nitrogen fertilization was observed for the dry mass production, from 5,840.80 kg ha-1 for plants lacking the nitrogen fertilization to 8,862.55 kg ha-1 for those fertilized with 225 kg ha-1 of N. Thus, while the nitrogen fertilization positively affected both tillering and morphogenesis, the N doses used in this study were insufficient to induce any change in the chemical composition of the aruana grass.

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Morphogenesis of Cynodon cultivars fertilized with nitrogen

Bioscience Journal ◽

10.14393/bj-v36n2a2020-42469 ◽

2020 ◽

Vol 36 (2) ◽

Author(s):

Luiz Barreto De Morais Neto ◽

Maria Socorro De Souza Carneiro ◽

Marcos Neves Lopes ◽

Magno José Duarte Cândido ◽

Elzânia Sales Pereira

Keyword(s):

Nitrogen Fertilization ◽

Stem Elongation ◽

Leaf Length ◽

Elongation Rate ◽

Mean Values ◽

Nitrogen Levels ◽

Randomized Design ◽

Number Of Leaves ◽

Senescence Rate ◽

Completely Randomized Design

To evaluate the biomass flow of two cultivars of Cynodon (Tifton 85 grass and vaquero grass) fertilized with increasing levels of nitrogen (N) (control – without nitrogen; 200; 400 and 600 mg dm-3) under greenhouse conditions, this study was carried out, in a completely randomized design, with factorial arrangement. Forages were examined during three regrowth cycles, with results presented as mean values of the cycles. In the analysis of the effect of nitrogen fertilization, the Tifton 85 grass showed an increasing response to nitrogen levels for the leaf elongation rate (LER). The vaquero grass had a quadractic response for the LER with increasing levels of N. As for the stem elongation rate, there was an increasing linear response in both grasses according to increasing levels of N. The leaf senescence rate (LSR) of the Tifton 85 grass has been enhanced by nitrogen fertilization. The vaquero grass revealed a quadractic response for this variable LSR with nitrogen fertilization, with a minimum value of 0.96 cm tiller-1 day-1 with nitrogen level of 42.5 mg dm-3. The phyllochron and the total number of leaves of both grasses have been influenced by nitrogen fertilization, with downward and upward linear responses, respectively, with increasing levels of nitrogen. For the final mean leaf length (MLL) of both forages, we verified an increasing response with increasing levels of nitrogen. Tifton 85 grass and vaquero grass presented similar LER in the absence of nitrogen, but higher values were observed for the fertilized Tifton 85 grass. The fertilization using nitrogen leads to positive responses of the biomass flow of Tifton 85 grass and vaquero grass under the conditions of the present study.

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Morphogenetic characteristics of three Brachiaria brizantha cultivars submitted to nitrogen fertilization

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652013005000004 ◽

2013 ◽

Vol 85 (1) ◽

pp. 371-377 ◽

Cited By ~ 1

Author(s):

Marcos F Silva ◽

Edson M. V Porto ◽

Dorismar D Alves ◽

Cláudio M.T Vitor ◽

Ignacio Aspiazú

Keyword(s):

Nitrogen Fertilization ◽

Leaf Blade ◽

Elongation Rate ◽

Leaf Elongation ◽

Brachiaria Brizantha ◽

Nitrogen Levels ◽

Appearance Rate ◽

Leaf Elongation Rate ◽

Leaf Appearance Rate ◽

Leaf Appearance

This study aims to evaluate the morphogenetic characteristics of three cultivars of Brachiaria brizantha subjected to nitrogen fertilization. The design was a randomized block in factorial arrangement 4x3; three cultivars of B. brizantha - Marandu, Piatã, Xaraés and four nitrogen levels - 0, 80, 160 and 240 kg/ha, with three replications. The experimental units consisted of plastic pots filled with 5 dm3 of soil. Thereupon the establishment fertilization, varieties were sowed directly in the pots, leaving, after thinning, five plants per pot. Forty-five days after planting, it was done a standardization cut at 10 cm tall. Nitrogen levels were distributed according to the treatments, divided in three applications. The morphogenetic characteristics were evaluated in three tillers per sampling unit and data were submitted to analysis of variance and regression. For all evaluated characteristics there was no interaction between factors cultivar and nitrogen levels, verifying only the effects of nitrogen on the variables leaf appearance rate and phyllochron. The dose 240 kg/ha of N corresponds to the greater leaf appearance rate. Cultivar Marandu shows the higher leaf blade: pseudostem and ratio of leaf elongation rate and elongation pseudostem, which favors higher forage quality.

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Competitiveness of alexandergrass or Bengal dayflower with soybean

Planta Daninha ◽

10.1590/s0100-83582010000300008 ◽

2010 ◽

Vol 28 (3) ◽

pp. 515-522 ◽

Cited By ~ 7

Author(s):

A.C.R. Dias ◽

S.J.P. Carvalho ◽

L.W. Marcolini ◽

M.S.C. Melo ◽

P.J. Christoffoleti

Keyword(s):

Competitive Ability ◽

Dry Mass ◽

Total Density ◽

Weed Species ◽

Replacement Series ◽

Commelina Benghalensis ◽

Randomized Design ◽

Full Flowering ◽

Completely Randomized Design ◽

Soybean Plants

Weeds compete with field crops mainly for water, light and nutrients, and the degree of competition is affected by the weed density and the intrinsic competitive ability of each plant species in coexistence. The objective of this research was to compare the competitiveness of alexandergrass (Brachiaria plantaginea) or Bengal dayflower (Commelina benghalensis) in coexistence with soybean, cv. M-Soy 8045. A factorial experiment (2 x 5) with two weed species and five competition proportions was carried out in a completely randomized design with four replicates. Proportions were based on a replacement series competition design, always maintaining the total density of four plants per 10 L plastic pots, which corresponded to 60 plants m ². The weed-crop proportions were: 0:4; 1:3; 2:2; 3:1; 4:0; that corresponded to the proportion of 100, 75, 50, 25 and 0% of soybean plants and the opposite for weeds, B. plantaginea or C. benghalensis plants. Leaf area, shoot dry mass of the weeds and soybean and number of soybean trifoliate leaves were evaluated when the soybean reached the phenologic stage of full flowering. B. plantaginea was a better competitor than soybean plants. Otherwise, C. benghalensis revealed a similar competitive ability that of the soybean. In both cases, there were evidences that intraspecific competition was more important.

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INFLUENCE OF SUGARCANE STRAW AND SOWING DEPTH ON THE EMERGENCE OF WEED SPECIES

Planta Daninha ◽

10.1590/s0100-83582015000300003 ◽

2015 ◽

Vol 33 (3) ◽

pp. 405-412 ◽

Cited By ~ 2

Author(s):

P. V. SILVA ◽

P. A. MONQUERO ◽

F. B. SILVA ◽

N. C. BEVILAQUA ◽

M. R. MALARDO

Keyword(s):

Ricinus Communis ◽

Seedling Emergence ◽

Dry Mass ◽

Weed Species ◽

Sowing Depth ◽

Sugarcane Straw ◽

Randomized Design ◽

Significant Difference ◽

Completely Randomized Design ◽

Luffa Aegyptiaca

ABSTRACT This study aimed to understand the influence of sowing depth and the amount of sugarcane straw on the emergence of weed species Luffa aegyptiaca Miller (Cucurbitaceae); Mucuna aterrima Piper & Tracy (Fabaceae - Leguminosae) and Ricinus communis (Euphorbiaceae). A completely randomized design with a 5 x 4 x 3 factorial layout with four replications was used, at five sowing depths (0, 2, 4, 8 and 10 cm), four different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) and three different evaluation periods (7, 14 and 21 days after sowing). After sowing, different amounts of sugarcane straw (0, 5, 10 and 15 t ha-1) were deposited on soil. Seedling emergence was analyzed at 7, 14 and 21 days after sowing, counting the number of seedlings that had emerged. At the end of the trial, weed height (cm), leaf area (cm2) and shoot dry mass (g) were measured. In relation to emergence ability, studied species presented different responses according to sowing depth and to the amount of sugarcane straw deposited on the soil. For the L.aegyptiacaand M.aterrima, no significant difference was observed in the interaction between depth and sugarcane straw, showing the adaptation of these species to no-burn sugarcane system. For R.communis, seeds placed at 0 cm of sugar cane straw depth were observed to favor the emergence of seedlings.

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Managment of sulphur fertilizer in forage sorghum crop cultivated in eutrophic Cambisol with alkaline pH

Australian Journal of Crop Science ◽

10.21475/ajcs.19.13.08.p1530 ◽

2019 ◽

pp. 1258-1266 ◽

Cited By ~ 1

Author(s):

Thiago Henrique Ferreira Matos Castañon ◽

Boanerges Freire de Aquino ◽

Edna Maria Bonfim Silva ◽

Izabel Maria Almeida Lima ◽

Ana Paula Alves Barreto Damasceno

Keyword(s):

Elemental Sulfur ◽

Chemical Properties ◽

Dry Mass ◽

Alkaline Ph ◽

Single Superphosphate ◽

Soil Fertilization ◽

Forage Sorghum ◽

Randomized Design ◽

Sulphur Fertilizer ◽

Completely Randomized Design

The objective of this study was to analyze the effect of soil fertilization with sulfur-based fertilizers, sulfate and elemental sulfur forms on biomass production, nutrient characteristics of sorghum and soil chemical properties. The experiment was carried out in a 4 x 4 factorial scheme (four sulfur sources: single superphosphate, agricultural gypsum, elemental sulfur powder and elemental sulfur granulated with bentonite, and four sulfur doses: 0, 40, 80, 120 mgdm-3) using four replications in a completely randomized design, being cultivated in pots under greenhouse conditions. The sorghum was cultivated for a period of 51 days after emergence of the seedlings. The shoot dry mass, shoot macronutrients content, root and soil and pH of the soil were evaluated. There were interactions between sources and sulfur doses in the variables such as shoot dry mass, sulfur in the root, sulfur and calcium in the soil. Elemental sulfur (granulate) showed lower concentrations of phosphorus, sulfur and N:S ratio in the shoot. The concentrations of potassium, calcium and magnesium did not show significant differences, both for the shoot and the root. The pH of the soil was reduced depending on the sources and doses of elemental sulfur. The sources and doses of sulfur did not influence the levels of phosphorus, potassium, and magnesium in the soil. The elemental sulfur in the form of powder is the best source of sulfur for forage sorghum cultivated in soil with alkaline pH.

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Broccoli yield in response to top-dressing fertilization with green manure and biofertilizer

Revista CERES ◽

10.1590/s0034-737x2011000500016 ◽

2011 ◽

Vol 58 (5) ◽

pp. 645-650 ◽

Cited By ~ 1

Author(s):

Gilberto Bernardo de Freitas ◽

Márcio Sousa Rocha ◽

Ricardo Henrique Silva Santos ◽

Letícia Monteiro da Silva Freitas ◽

Leandro de Almeida Resende

Keyword(s):

Green Manure ◽

Mineral Fertilizer ◽

Dry Mass ◽

Experimental Unit ◽

Productive Performance ◽

Mineral Fertilization ◽

Randomized Design ◽

Protected Cultivation ◽

Completely Randomized Design ◽

Organic Compost

The objective of this work was to evaluate the productive performance of broccoli under different top-dressing organic fertilizations. The experiment was conducted under protected cultivation, in a completely randomized design with four replications, with two plants per experimental unit. Broccoli seedlings were produced in a commercial substrate in styrofoam trays. The seedlings were transplanted to plastic pots containing 10.0 L of substrate made up of subsoil and organic compost at the ratio of 3:1 (v/v), respectively, which is equivalent to about 20.0 t ha-1 of organic compost at planting. After seedling establishment, the top-dressing fertilization treatments were applied: gliricidia biomass associated or not with liquid biofertilizer of cattle manure to the soil and bokashi. Two control treatments were established: one with mineral fertilization recommended for the crop and the other without top-dressing fertilization. The broccoli production was evaluated (commercial standard). Plants that received mineral fertilizer were more productive, however, they were not significantly different (p>0.05), by Dunnet test, from the plants fertilized with 2.5 t ha-1 gliricidiabiomass (dry mass) associated with liquid biofertilizer (2.0 L m-2) applied to soil. Top-dressing fertilizations with only gliricidia, at 2.5 and 5.0 t ha-1 of biomass (dry mass), resulted in no significant increase in production of broccoli inflorescence. The use of bokashi in addition to gliricidia biomass and liquid biofertilizer reduced the efficiency of the fertilization compared with plants that received only gliricidia and liquid biofertilizer.

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Integrated management of tough lovegrass (Eragrostis plana Nees): associating chemical control tools and plant physiology

Ciência Rural ◽

10.1590/0103-8478cr20200271 ◽

2021 ◽

Vol 51 (2) ◽

Author(s):

Eduardo Avelino Faleiro ◽

Diego Martins Chiapinotto ◽

Fabiane Pinto Lamego ◽

Carlos Eduardo Schaedler ◽

Eduardo Bohrer de Azevedo

Keyword(s):

Solar Radiation ◽

Integrated Management ◽

Dry Mass ◽

Radiation Factor ◽

Factor B ◽

Randomized Design ◽

Completely Randomized Design ◽

Factor C ◽

Resource Conditions ◽

And Control

ABSTRACT: The objective of the study was to evaluate the efficiency of herbicides use in the control of tough lovegrass according to the availability of solar radiation and the presence or absence of flooded. Two experiments were conducted in a completely randomized design, in a 2x2x4 and 2x2x5 factorial scheme, where factor A was equivalent to the environment (natural or reduced radiation); factor B to water condition (with a 2 cm flooded or without); and, factor C the herbicides: cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), cyhalofop butyl + glyphosate (315 g ha-1 + 1080 g ha-1) and control (without application) in the first experiment. In the second experiment, the herbicides used were cyhalofop butyl (315 g ha-1), glyphosate (1080 g ha-1), sethoxydim (184g ha-1), imazethapyr (106 g ha-1) and control (without application). Glyphosate efficiently controls plants of tough lovegrass with four tillers (>90%), being superior to cyhalofop, imazethapyr and sethoxydim; independently, of resource conditions. Reduction in the availability of solar radiation generates less shoot dry mass production from the weed, and improves the control only by imazethapyr and cyhalofop. In general, a flooded condition does not affect tough lovegrass control by herbicides.

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EMISSÃO DE ÓXIDO NITROSO ASSOCIADO AO USO DE UREIA NO CULTIVO DE MELÃO AMARELO

Nativa ◽

10.31413/nativa.v6i6.5459 ◽

2018 ◽

Vol 6 (6) ◽

pp. 600

Author(s):

Vanessa Cláudia Vasconcelos Segundo ◽

Renato Innecco ◽

Ebenézer De Oliveira Silva

Keyword(s):

Leaf Area ◽

Aerial Part ◽

Dry Mass ◽

Nitrogen Fertilizers ◽

Root Part ◽

Randomized Design ◽

Number Of Leaves ◽

Completely Randomized Design ◽

Brazilian Northeast ◽

Total Soil Nitrogen

O meloeiro tem grande importância econômica para o Nordeste brasileiro. Entretanto, em seu cultivo utiliza-se insumos que podem prejudicar o ambiente; como, os fertilizantes nitrogenados. Objetivou-se avaliar a emissão de N2O em cultivo de meloeiro amarelo ‘Goldex’. O experimento foi instalado em delineamento inteiramente casualizado, com cinco repetições. Os tratamentos foram: 0 (controle), 1,0; 1,5 e 2 vezes a quantidade de nitrogênio recomendada para cada estádio. Foi analisado o fluxo de N2O, área foliar, número de folhas, massa seca da parte aérea, massa seca dos frutos, massa seca da parte radicular, nitrogênio total do solo, das plantas e N (NH4+ e NO3-) do solo. O fluxo de N2O teve comportamento temporal irregular durante a fase de plântulas e crescente na floração. Os tratamentos afetaram significativamente a área foliar, número de folhas, massa seca da parte aérea, massa seca da parte radicular, nitrogênio da parte aérea e parte radicular das plantas e do solo. A aplicação de nitrogênio, em dosagens superiores à recomendada, não aumentou a produção do meloeiro. E o cálculo do fator de emissão mostrou que a emissão do N2O não atingiu valores prejudiciais ao ambiente.Palavras-chave: fator de emissão, efeito estufa e nitrogênio. NITROUS OXIDE EMISSION ASSOCIATED WITH UREA USE THE YELLOW MELON CROP ABSTRACT: The melon has great economic importance for the Brazilian Northeast. However, in its cultivation uses inputs that can harm the environment; Such as nitrogen fertilizers. The objective of this study was to evaluate the emission of N2O in yellow 'Goldex' cultivar. The experiment was installed in a completely randomized design with five replications. The treatments were: 0 (control), 1.0; 1.5 and 2 times the amount of nitrogen recommended for each stage. N2O flux, leaf area, leaf number, shoot dry mass, fruit dry mass, dry mass of the root portion, total soil nitrogen, of the plants and N (NH4 + and NO3 -) of the soil were analyzed. The flow of N2O had irregular temporal behavior during the seedling phase and increased in flowering. The treatments affected significantly the leaf area, number of leaves, dry mass of the aerial part, dry mass of the root part, nitrogen of the aerial part and root part of the plants and the soil. The application of nitrogen, in dosages higher than the recommended one, did not increase the production of the melon. And the calculation of the emission factor showed that the emission of N2O did not reach values harmful to the environment.Keywords: emission fator, greenhouse and nitrogen.

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