scholarly journals The growth dynamics in Brachiaria species according to nitrogen dose and shade

2011 ◽  
Vol 40 (2) ◽  
pp. 270-276 ◽  
Author(s):  
Domingos Sávio Campos Paciullo ◽  
Priscila Beligoli Fernandes ◽  
Carlos Augusto de Miranda Gomide ◽  
Carlos Renato Tavares de Castro ◽  
Fausto de Souza Sobrinho ◽  
...  

It was studied the effects of shading (0, 36 and 54%) and of four nitrogen doses (0, 50, 100 and 150 mg N/dm³ of soil) on the morphogenetic traits and on the tillering of grasses of Brachiaria genus (B. decumbens, B. ruziziensis and B. brizantha cv. Marandu and cv. Xaraes), cultivated in pots with 5 kg substrate. It was used a complete random design, in a 3 × 4 × 4 factorial scheme with three replications. Nitrogen promoted increase in leaf appearance rate and in average leaf blade length, whereas shading increased stem elongation rate. Leaf elongation rate and tillering varied with the interaction among shading percentages and nitrogen doses. Shading increased response efficiency of leaf elongation rate to nitrogen doses, but reduced for tillering, evidencing priority existing tillering growth in detriment to appearance of new tillers when there is light restriction for the plants. Phenotypic adjustments, in response to light reduction, indicate that the studied grasses present tolerance to moderate shading.

2013 ◽  
Vol 85 (1) ◽  
pp. 371-377 ◽  
Author(s):  
Marcos F Silva ◽  
Edson M. V Porto ◽  
Dorismar D Alves ◽  
Cláudio M.T Vitor ◽  
Ignacio Aspiazú

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.


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 ◽  
...  

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.


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 ◽  
...  

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.


2020 ◽  
Vol 28 ◽  
pp. 11-23
Author(s):  
Tiago Barbalho André ◽  
Leonardo Bernardes Taverny de Oliveira ◽  
Antonio Clementino dos Santos

The objective of this work was to evaluate the effects promoted by full sun and natural shading (25%) enviroemnts , under the productive components of Panicum maximum cv. Mombasa grown in diferent levels of nitrogen (0, 25, 50, 100 kg ha-1 cycle-1 ). Urea was used as nitrogen source, applied on the surface. This study evaluated the following variables: number of total leaves (NTL), number of green leaves (NGL), number of dead leaves (NDL), leaf lifespan (LLS), sheath length (SL), stem elongation rate (SER), Phyllochron (PHYL), leaf appearance rate (LApR), leaf elongation rate (LElR), leaf senescence rate (LSR), average length of leaf blade (ALLB), leaf area index (LAI) and tiller population density (TPP). The shaded environment provided better conditions for sheath length and leaf elongation rate, however in full sun the tiller density was higher.


2021 ◽  
Vol 73 (6) ◽  
pp. 1413-1421
Author(s):  
M.E.R. Santos ◽  
I.C. Ferreira ◽  
B.H.R. Carvalho ◽  
G.O. Rocha ◽  
G.S. Borges ◽  
...  

ABSTRACT The objective this study was to identify differences in the morphogenic patterns of four Urochloa brizantha cultivars (marandu, piatã, xaraés and paiaguás grasses) during the stockpiling period. A completely randomized design was used, with three replications, in experimental plots of 9m². The evaluations took place over 2 years. The grasses were stockpiled for 92 (Year 1) and 95 (Year 2) days. The leaf appearance rate of paiaguás grass was higher, compared to other grasses. In Year 1, the stem elongation rate of xaraés grass was higher than other grasses. At the end of stockpiling period of Year 1, the tiller population density (TPD) was higher in the paiaguás grass, intermediate in the xaraés and marandu grasses and lower in the piatã grass. At the end of the stockpiling period in Year 2, TPD was higher in the paiaguás grass canopy, intermediate in the marandu and piatã grasses canopies, and lower in the xaraés grass canopy. Paiaguás grass has greater leaf growth during the stockpiling period and is therefore suitable for use under stockpiled grazing. Xaraés grass has high stem elongation during the stockpiling period, which is why its use under stockpiled grazing must be accompanied by adjustments in pasture management.


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 ◽  
...  

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.


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 ◽  
...  

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.


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

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.


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 ◽  
...  

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.


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