scholarly journals Effects of postgrazing residue on morphogenetic and structural characteristics of Tifton 85 pastures

2016 ◽  
Vol 37 (4) ◽  
pp. 2043
Author(s):  
Wilton Ladeira Silva ◽  
Ana Cláudia Ruggieri ◽  
Ricardo Andrade Reis ◽  
Américo Garcia Silva Sobrinho ◽  
Euclides Braga Malheiros
Keyword(s):  
Structural Characteristics ◽  
Stem Elongation ◽  
Light Interception ◽  
Climatic Conditions ◽  
Leaf Length ◽  
Elongation Rate ◽  
Area Index ◽  
Structural Variables ◽  
Senescence Rate ◽  
Leaf Appearance

The ideal time to start grazing is when pastures reach 95% light interception. The use of residual leaf area index (rLAI) to time the interruption of grazing under intermittent grazing has recently been studied in forage species in different climatic conditions in Brazil. However, studies evaluating the formation and development of leaves and tillers through morphogenetic and structural variables in functional rLAI are still lacking for Tifton 85 pastures. Therefore, the objective of this study was to evaluate the effects of varying rLAI in successive grazing cycles on morphogenetic and structural characteristics of Tifton 85 pasture grazed intermittently by sheep. Morphogenetic and structural characteristics were evaluated in three grazing cycles under three rLAI conditions (0.8, 1.6, and 2.4). The regrowth interval (time taken to return to 95% light interception) of pastures increased from 21.33 to 29.66 days with decreasing rLAI. The leaf appearance rate increased at a rate of 0.02 leaves tiller-1 day-1 and the number of live leaves per tiller increased by 0.41 with decreasing rLAI. Phyllochron, leaf elongation rate, final leaf length, leaf senescence rate, and stem elongation rate decreased linearly with decreasing rLAI. The number of live leaves per tiller was lower (7.97) in the third grazing cycle, probably owing to the higher senescence rate observed that same cycle, while the other variables had higher values. The 2.4 rLAI condition promotes excessive stem elongation, reduced leaf appearance, lower number of live leaves per tiller, and increased senescence of leaves, while the 0.8 and 1.6 rLAI conditions promote desirable morphogenetic and structural characteristics, which correlate directly with forage quality. In order to avoid excessive forage losses, grazing must occur preferentially by the end of March, when climatic conditions still support the appropriate development of the plants.

scholarly journals Establishment of Brachiaria cultivars in the soil-climatic conditions of the Brazilian semi-arid region

2020 ◽  
Vol 43 ◽  
pp. e51802
Author(s):  
Jéssica Gomes Rodrigues ◽  
Gelson dos Santos Difante ◽  
Antonio Leandro Chaves Gurgel ◽  
Emmanuel Lievio de Lima Veras ◽  
Ana Beatriz Graciano da Costa ◽  
...  
Keyword(s):  
Arid Region ◽  
Structural Characteristics ◽  
Stem Elongation ◽  
Climatic Conditions ◽  
Leaf Length ◽  
Elongation Rate ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Semi Arid Region ◽  
Semi Arid

This study aimed was the establishment of the genus Brachiaria in the Brazilian semi-arid region. The experiment was conducted from April to June 2016, as a randomized-block experimental design with five treatments and four replicates. Treatments were represented by five Brachiaria cultivars, namely, Marandu, Paiaguás, Piatã, Xaraés and Basilisk. Morphogenetic (leaf appearance rate, leaf elongation rate e stem elongation rate) and structural characteristics (final leaf length, tiller population density e number of leaves per tiller, forage mass, leaf blade mass, stem mass, senescent material mass and leaf:stem ratio) of the forage cultivars were evaluated. Canopy height fitted a linear regression model (P<0,05), with estimated daily increases of 0.50, 0.53, 0.53, 0.54 and 0.56 cm for cvs Basilisk, Marandu, Paiaguás, Piatã and Xaraés, respectively. The number of live leaves in cvs Basilisk and Paiaguás increased linearly (p < 0.05), by 4.3 and 2.8 leaves per tiller, respectively, during the 60-day period. The recommended height at which the growth of Brachiaria cultivars should be interrupted is upon reaching 25 to 35 cm. In the soil-climatic conditions of the Brazilian semi-arid region, the Brachiaria cultivars Basilisk, Marandu, Paiaguás, Piatã and Xaraés are established at 75 days after sowing, which is the recommended time for performing the first harvest or lenient grazing to stimulate tillering.

scholarly journals MORPHOGENETIC AND STRUCTURAL CHARACTERISTICS OF GUINEA GRASS PASTURES UNDER ROTATIONAL STOCKING STRATEGIES

2016 ◽  
Vol 54 (2) ◽  
pp. 243-256 ◽  
Author(s):  
ANDERSON DE MOURA ZANINE ◽  
DOMICIO NASCIMENTO ◽  
WILTON LADEIRA DA SILVA ◽  
BRAULIO MAIA DE LANA SOUSA ◽  
DANIELE DE JESUS FERREIRA ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Stem Elongation ◽  
Management Strategies ◽  
Light Interception ◽  
Elongation Rate ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Guinea Grass ◽  
Leaf Appearance ◽  
Lower Stem

SUMMARYThe objective of this study was to evaluate morphogenetic and structural characteristics of Guinea grass pastures subjected to two grazing frequencies (90 and 95% light interception) and two post-grazing heights (30 and 50 cm), during the rainy season and dry year. The leaf appearance rate varied only in the summer, the grazing pastures managed at 90/50 (light interception/post-grazing height) presented higher values in the leaf appearance rate (0.440 leaf/tiller.day), compared with those managed at 90/30 (0.275 leaf/tiller.day) and 95/50 (0.228 leaf/tiller.day), respectively. In the winter/beginning of the spring, pastures managed at 90/30 (0.03 cm/tiller.day) presented lower stem elongation rate in comparison with those managed at 90/50 (0.19 cm/tiller.day) and 95/30 (0.16 cm/tiller.day). Management strategies do not compromise the tissue flow in tillers and, consequently, can be utilized for the management of Guinea grass.

scholarly journals Effects of stubble height and season of the year on morphogenetic, structural and quantitative traits of Tanzania grass

2021 ◽  
Vol 9 (3) ◽  
pp. 256-267
Author(s):  
Nauara Moura Lage Filho ◽  
Aline Da Rosa Lopes ◽  
Aníbal Coutinho Do Rêgo ◽  
Felipe Nogueira Domingues ◽  
Cristian Faturi ◽  
...  
Keyword(s):  
Stem Elongation ◽  
Block Design ◽  
Climatic Conditions ◽  
Elongation Rate ◽  
Panicum Maximum ◽  
Area Index ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Guinea Grass ◽  
Leaf Appearance

The objective of this study was to evaluate regrowth period (RP), morphogenetic, structural and productive characteristics of the guinea grass cultivar Tanzania [Megathyrsus maximus (syn. Panicum maximum)] under different stubble heights (SH) during dry (DS) and rainy (RS) seasons in the eastern Amazon region. The treatments were: 5, 15, 25, 35, 45 and 55 cm SH, distributed in a randomized complete block design with 6 replicates. In the 2 seasons, RP decreased linearly with increase in SH, and was considerably shorter in the RS (47 d). Leaf appearance rate decreased linearly from 0.071 to 0.051 leaves/tiller/d with increasing SH, and it was higher during the RS. Increase in SH increased leaf elongation rate, stem elongation rate and leaf area index. In the RS, climatic conditions favored the morphogenesis, resulting in higher herbage accumulation (8,693 kg DM/ha) than in the DS (2,597 kg DM/ha). In associating seasons with SH, we recommend that Tanzania grass be managed at SH between 35 and 45 cm in the DS, resulting in RP from 61 to 64 days, and at SH of 35 cm in the RS, resulting in RP of 41 days. Studies to test this management strategy seem warranted.

scholarly journals Morphogenesis and structure of mombassa grass over different growth periods

2017 ◽  
Vol 38 (5) ◽  
pp. 3271
Author(s):  
Márcio Odilon Dias Rodrigues ◽  
Antonio Clementino dos Santos ◽  
Marcos Odilon Dias Rodrigues ◽  
Rubens Ribeiro da Silva ◽  
Otacilio Silveira Junior
Keyword(s):  
Structural Characteristics ◽  
Stem Elongation ◽  
Pearson Correlation ◽  
Block Design ◽  
Elongation Rate ◽  
N Fertilizer ◽  
Panicum Maximum ◽  
Forage Production ◽  
Leaf Elongation ◽  
Leaf Appearance

This study aimed to evaluate the effect of nitrogen (N) fertilizer doses on morphogenic and structural characteristics of mombassa grass (Panicum maximum Jacq.) at three different periods of the lifespan of tillers. The experiment was conducted in Araguaína-TO, Brazil, from December 2014 to February 2015. It was installed in split plots in a randomized block design with four replications. The doses of N-fertilizer (0, 30, 60, 90 kg N.ha-1) were the plots and the periods evaluated (1PER – first period from day 16 to 30; 2PER from day 31 to 45 and 3PER from day 46 to 60 after germination) were the subplots. The evaluated variables consisted of leaf appearance rate (LAR), leaf elongation rate (LER), stem elongation rate (SER), leaf senescence rate (LSR), phyllochron, tiller number, leaf emergence, and total leaf number. A Pearson correlation analysis was used to morphogenic and structural characteristics along with a regression analysis for all the variables. Overall, increasing N-fertilizer doses positively influenced the leaf appearance and leaf elongation rates, tiller density, and the number of live leaves per tiller. The 90-kg N.ha-1 dose enabled the best morphogenic and structural responses of the forage when compared to the other rates. Each period featured differently, with higher values of LSR, SER, and LER in 3PER when compared to those in 2PER and in 1PER. Therefore, the nutritional supply over the first weeks of tiller lives was defining to an increase in forage production in the remaining periods. In light of this, we observed that as LAR raise in the first days after germination, nutritional supplies are required from day 15 on, mainly nitrogen, so plants could continue their development since initial plant growth determines pasture productive vigor and longevity.

scholarly journals Morphogenetic and structural characteristics of clones of elephant grass managed under intermittent stocking

2016 ◽  
Vol 37 (4) ◽  
pp. 2099
Author(s):  
Priscila Beligoli Fernandes ◽  
Carlos Augusto Brandão de Carvalho ◽  
Domingos Sávio Campos Paciullo ◽  
Carlos Augusto De Miranda Gomide ◽  
Mirton José Frota Morenz ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Stem Elongation ◽  
Elongation Rate ◽  
Leaf Life Span ◽  
Elephant Grass ◽  
Leaf Elongation ◽  
Appearance Rate ◽  
Randomized Experimental Design ◽  
Leaf Appearance Rate ◽  
Leaf Appearance

This work was carried out to evaluate the morphogenetic and structural characteristics of basal and aerial tillers of two dwarf elephant grass clones (BRS Kurumi and CNPGL 00-1-3) managed under intermittent stocking in six grazing cycles. A completely randomized experimental design with three replications (paddocks) in split-split-plot arrangements was used. The clones were allocated to the plots, tiller classes were assigned to the subplots and grazing cycles to sub subplots. Higher values for basal tillers than aerial tillers were seen for the following characteristics: leaf elongation rate (12.8 and 5.1 cm/tiller/day), leaf appearance rate (0.26 and 0.19 leaves/tiller/day), stem elongation rate (0.38 and 0.16 cm/tiller/day), senescence rate (0.98 and 0.47 cm/tiller/day), total number of leaves (9.3 and 7.1 leaves/ tiller), number of live leaves (7.7 and 5.8 leaves/tiller) and final length of leaf blades (33.5 and 20.0 cm). Phyllochron was lower for basal (4.0 days/leaf) than aerial tillers (5.5 days/leaf). The leaf life span increased with the advance of the grazing cycles, averaging 31.2 days. The tiller density increased with the advance of the grazing cycles showing an average increase of 167% of aerial tillers and 62% of basal tillers for both clones. The morphogenetic and structural characteristics of dwarf clones were influenced jointly by the clones and the availability of the environmental factors of growth during the spring and summer. The high leaf elongation rates, associated with high leaf appearance rate, reveal the potential of high production dry matter of leaves and restoration of leaf area after grazing.

scholarly journals Morphogenetic and structural characteristics of xaraes palisadegrass submitted to cutting heights

2011 ◽  
Vol 40 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Braulio Maia de Lana Sousa ◽  
Domicio do Nascimento Júnior ◽  
Carlindo Santos Rodrigues ◽  
Hélida Christhine de Freitas Monteiro ◽  
Sila Carneiro da Silva ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Stem Elongation ◽  
Block Design ◽  
Growth Conditions ◽  
Light Interception ◽  
Elongation Rate ◽  
Cutting Condition ◽  
Leaf Elongation ◽  
Randomized Block Design ◽  
Leaf Elongation Rate

The objective of this work was to evaluate the morphogenetic and structural characteristics of xaraes palisadegrass submitted to three cutting heights (15, 20 and 25 cm) when the sward reached 95% of light interception during regrowth. The experiment was carried out according to a complete randomized block design with three replications. The sward surface height under the cutting condition of 95% of light interception was very homogeneous with values around 30 cm. The increase in cutting height reduced the leaf elongation rate and the number of live leaves but increased stem elongation rate. As the cutting criterion was the same, before the intense competition for light, the variation in the cutting severity had a small influence on the morphogenetic and structural characteristics of this grass. In the summer, due to the better growth conditions, the plants presented a higher tissue renewal, which was characterized by a higher leaf elongation rate, reduced leaf lifespan and leaf senescence rate when compared to the other season of the year. Under intermittent defoliation conditions, the regrowth of xaraes palisadegrass can be interrupted at a sward height of 30 cm (frequency) keeping a residual height of 15 cm.

scholarly journals Morphogenic and structural characteristics of Panicum cultivars during the establishment period in the Brazilian Northeast

2020 ◽  
Vol 43 ◽  
pp. e50984
Author(s):  
Ana Beatriz Graciano da Costa ◽  
Gelson dos Santos Difante ◽  
Antonio Leandro Chaves Gurgel ◽  
Emmanuel Lievio de Lima Veras ◽  
Jéssica Gomes Rodrigues ◽  
...  
Keyword(s):  
Population Density ◽  
Leaf Blade ◽  
Structural Characteristics ◽  
Stem Elongation ◽  
Elongation Rate ◽  
Panicum Maximum ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Leaf Appearance ◽  
Brazilian Northeast

This study aimed to evaluate the morphogenic and structural characteristics of six Panicum maximum cultivars during the establishment period. A completely randomized block design with four replicates and six treatments (Tamani, Mombaça, Massai, Tanzania, Aruana and Zuri cultivars) was used. Morphogenic (leaf appearance rate, leaf elongation rate e stem elongation rate), structural (final leaf length, tiller population density e number of leaves per tiller) and productive (forage mass, leaf blade mass, stem mass, senescent material mass and leaf:stem ratio) characteristics were evaluated. There was no difference (p > 0.05) between the cultivars in terms of the number of live leaves per tiller (2.95 leaves/tiller). Mombaça cultivar had (p < 0.05) higher canopy height (50.64 cm) compared with other cultivars. The highest (p < 0.05) tiller population density was observed in Tamani (235.90 tillers m-2) and Massai (201.60 tillers m-2) cultivars. Leaf lifespan (54.18 days), phyllochron (17.40 days/leaf) and leaf senescence rate (0.87 cm tiller day-1) were not different (p > 0.05) between cultivars. However, leaf appearance rate was higher (p < 0.05) in Tanzania (0.07 leaves tiller day-1) than in Aruana cultivar (0.05 leaves tiller day-1). Leaf blade mass was higher (p < 0.05) in Mombaça cultivar (1518.31 kg DM ha-1), whereas Massai showed higher (p < 0.05) leaf:stem ratio (9.25). Panicum cultivars Tamani, Tanzania and Massai establishment after 75 days, while the other cultivars establish at 105 days of sowing in the Brazilian Northeast.

scholarly journals Morphogenetic and structural comparative characterization of tropical forage grass cultivars under free growth

2010 ◽  
Vol 67 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Márcia Cristina Teixeira da Silveira ◽  
Domicio do Nascimento Júnior ◽  
Sila Carneiro da Silva ◽  
Valéria Pacheco Batista Euclides ◽  
Denise Bataglin Montagner ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Stem Elongation ◽  
Survival Rates ◽  
Group Analysis ◽  
Leaf Length ◽  
Leaf Life Span ◽  
Large Variability ◽  
Tropical Forage ◽  
Structural Variables ◽  
Free Growth

Understanding of the morphogenetic characteristics allows comprehension of aspects related to the form and function of forage plants, providing opportunities to identify potentially high productive plants and distinct defoliation management requirements. The objective of this experiment was to carry out a comparative study of ten tropical forage grasses using morphogenetic and structural variables. Treatments corresponded to grasses of the Panicum genus (P. maximum cultivars Tanzânia and Mombaça) and the Brachiaria genus (B. brizantha cultivars Piatã, Marandu, Xaraés, Capiporã and Arapoty; B. decumbens cultivar Basilisk; B. humidicola cultivars Comum and Tupi), evaluated under free growth conditions.. Response variables were leaf appearance and elongation rates, phyllochron, stem elongation rate, final leaf length, number of live leaves per tiller, leaf life span and tiller appearance, death and survival rates. There was difference between cultivars for these variables, indicating a large variability within plants. Considering the morphogenetic and structural variables of leaves and tillers, B. brizantha had a similar pattern of variation to those of P. maximum, and B. Decumbens, similar to those of B. humidicola. Tiller appearance was large at the onset of the experiment and second and third generations comprised the large majority of tiller population for the cultivars Mombaça, Tanzânia, Xaraés and Capiporã. Group analysis based on plant morphogenetic and structural characteristics of leaves and tillers was an interesting way of grouping cultivars, indicating the importance and the potential of using morphogenesis in plant selection and evaluation programmes.

scholarly journals Morphogenesis of Cynodon cultivars fertilized with nitrogen

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.

scholarly journals Morphogenetic and structural characteristics of Megathyrsus maximus cv. Centenário under defoliation intensities

2020 ◽  
Vol 9 (5) ◽  
pp. e120953284
Author(s):  
Newton de Lucena Costa ◽  
Liana Jank ◽  
João Avelar Magalhães ◽  
Amaury Bularmaqui Bendahan ◽  
Braz Henrique Nunes Rodrigues ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Canopy Structure ◽  
Leaf Length ◽  
Intensity Level ◽  
Area Index ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Forage Utilization ◽  
Leaf Appearance ◽  
Soil Level

The effect of defoliation intensities (20, 30, 40 and 50 cm above soil level) on green dry matter (GDM) yield and morphogenetic and structural characteristics of Megathyrsus maximus cv. Centenário were evaluated under field conditions in Roraima´s savannas. The effects of defoliation intensities on the GDM yields, leaf area index and leaf elongation rates was adjusted to the quadratic regression model and maximum values recorded with cutting at 35.8; 44.9 and 30.2 cm above soil level, respectively. The tiller population density, number of leaves tiller-1 and leaf appearance rate was inversely proportional to the intensity of defoliation, while the opposite occurred for to average leaf length and leaf senescence rate. Apical meristem removal percentage was higher with increasing defoliation intensity. Vigor regrowth showed close negative correlation with defoliation intensity level. Pastures of M. maximus cv. Centenário managed under 30 to 35 cm residue provides higher forage productivity, larger efficiency of forage utilization, greater tissue renewal and canopy structure more favorable to grazing.

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