scholarly journals Characterization of tropical forage grass development pattern through the morphogenetic and structural characteristics

2011 ◽  
Vol 40 (3) ◽  
pp. 527-534 ◽  
Author(s):  
Carlindo Santos Rodrigues ◽  
Domicio do Nascimento Júnior ◽  
Sila Carneiro da Silva ◽  
Márcia Cristina Teixeira da Silveira ◽  
Braulio Maia de Lana Sousa ◽  
...  

An experiment was carried out with the objective to evaluate growth pattern of tropical forage grass under free growth by using morphogenetic and structural characteristics with the expectation of using this study for forage grass evaluation protocol. The experimental area was established with two cultivars of Panicum maximum Jacq. (Mombaca and Aruana), a hybrid cultivar of P. maximum Jacq. and P. Infestum BRA-7102 (Massai), two cultivars of Brachiaria brizantha (A. Rich.) Stapf (Marandu and Xaraes) and Molasses grass (Melinis minutiflora Beauv.) and jaragua grass (Hyparrhenia rufa (Nees) Stapf.). The grasses were planted in 1.0-m² experimental units with 24 plants arranged in a completely randomized block design with three replications. Growth pattern of the grasses was evaluated through mass development, tiller mortality, development stage and leaf longevity. Development patterns differed significantly among groups of grasses, indicating that the same available resources can be used in different manners by grasses from the same genus and/or species.

2016 ◽  
Vol 37 (3) ◽  
pp. 1209
Author(s):  
Núbia Maria Correia ◽  
Leonardo José Petean Gomes

The objective of this study was to evaluate the soybean oversowing with braquiarão (Urochloa brizantha cv. Marandu) and colonião (Panicum maximum cv. Aruana) and the capacity of these forage crops to produce dry mass during the fall-winter-spring period. Two experiments, one for each forage species, were conducted in field conditions in the 2011/2012 season and were repeated in 2012/2013. The experimental set-up was arranged in a randomized block design with four repetitions in a 2 x 5 factorial. The soybean oversowing was studied in the development stages R6 and R8 (2011/2012) or R5 and R8 (2012/2013) with braquiarão or colonião grass in five seed amounts (200, 400, 600, 800 and 1000 points of cultural value – PCV = seeds amount x culture value). In both seasons, the braquiarão oversowing at soybean stages R5 and R6 resulted in higher dry mass production, when compared to stage R8. Additionally, the amount of 600 seeds PCV was sufficient to obtain an excellent percentage of soil cover (>95%), in addition to the satisfactory number of plants per m2 and the dry mass production. On the other hand, independent of the soybean development stage in the oversowing moment, colonião was not promising for use in this sowing type because its low stand and irregular soil covering, even at the higher seed amounts.


2019 ◽  
Vol 40 (6Supl2) ◽  
pp. 3167 ◽  
Author(s):  
Alice Mariana Hupp Sacramento ◽  
Olga Cedro de Menezes ◽  
Tarcísio Marques Barros ◽  
Diego Novais Pinheiro ◽  
Soraya Maria Palma Luz Jaeger ◽  
...  

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.


2020 ◽  
Author(s):  
Jalise Fabíola Tontini ◽  
Cesar Henrique Espírito Candal Poli ◽  
Viviane da Silva Hampel ◽  
Mariana de Souza Farias ◽  
Neuza Maria Fajardo ◽  
...  

AbstractTropical sward characteristics can alter lamb ingestive behavior. Our study evaluated the ingestive behavior of young lambs in different tropical pastures to identify which variables interfere in their grazing activity. Two years of study were carried out with 54 weaned lambs distributed in three different swards: 1) monoculture of a upright grass, guinea grass (Panicum maximum; GG); 2) monoculture of a shrubby legume pigeon pea (Cajanus cajan; PP) and 3) contiguous areas with half the paddock with GG and half with PP (GP). The experiment was set out in a randomized complete block design. Lamb ingestive behavior was observed from sunrise to sunset with records every 5 minutes. To identify the main variables that affected with the lamb grazing activity, a multivariate analysis of the Decision Tree was performed. Our results showed that there was no difference in the ingestive behavior parameters of young lambs in different swards (P > 0.05). There was interaction among the swards and the experimental periods for the variables idleness time and biting rate (P ≤ 0.05). Grazing time of the animals increased 40% with experimental period progression. The Decision Tree identified leaf:stem ratio as the variable that most influenced lamb grazing time in GG and GP swards while in the PP sward grazing time was directly related to the pasture height. The behavior of young lambs on tropical pasture is variable as there is a change in the behavioral response over time. In addition, the grazing time of these animals can be estimated by means of variables related to pasture structural characteristics (leaf:stem ratio and height) together with chemical variables.


2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Suzete Fernandes Lima ◽  
Leandro Spíndola Pereira ◽  
Gustavo Dorneles Sousa ◽  
Simonny Araújo Vasconcelo ◽  
Adriano Jakelaitis ◽  
...  

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.


2020 ◽  
Vol 12 (3) ◽  
pp. 1005
Author(s):  
Xiaodong Chen ◽  
Jinggui Wu ◽  
Yaa Opoku-Kwanowaa

Returning straw plays an important role in protecting the environment and maintaining the sustainable development of agriculture. In this research, we explored the effects of returning granular corn straw on soil humus composition and humic acid structural characteristics in a typical saline-alkali soil. This study was conducted in Jilin province. A randomized block design consisting of nine plots with three treatments in three replicates was used for this study. The treatments were granular corn straw (GS), coarse corn straw (CS), and control (CK). The results show that treatments GS and CS both increased the contents of soil humus and its components in the soil compared to CK. However, treatment GS recorded the highest significant increase in soil humus carbon (HEC), fulvic acid carbon (FAC), and humic acid carbon (HAC) by 17.59%, 8.32%, and 26.51%, respectively. Comparing the two straw treatments, it was found that the relative intensities of treatment GS at 2920 and 2850 cm−1 were higher than treatment CS by 1.58% and 72.49%, respectively. The relative intensities of treatment GS at 1720 cm−1 and 1620 cm −1 were lower than treatment CS by 52.2% and 30.43%, respectively. Moreover, an analysis of soil humic acid (HA) through an infrared spectrum, fluorescence spectrum, and principal components analysis (PCA) showed that the application of straw makes the structure of HA aliphatic, simple, and younger, and also promotes the continuous renewal of humus. In this study, the application of granular corn straw effectively improved the soil humus content and humic acid structural characteristics and is thus highly recommended.


2018 ◽  
Vol 31 (4) ◽  
pp. 963-971 ◽  
Author(s):  
WELSON LIMA SIMÕES ◽  
MARCELO CALGARO ◽  
MIGUEL JULIO MACHADO GUIMARÃES ◽  
ANDERSON RAMOS DE OLIVEIRA ◽  
MÍRIAN PAULA MEDEIROS ANDRÉ PINHEIRO

ABSTRACT Sugarcane is one of the most affected crops by water scarcity. The efficient use of the irrigation water is an alternative to minimize this problem. The objective of this work was to evaluate biometric parameters, yield, and technological quality of sugarcane plants subjected to different controlled water deficit regimes in the sub-middle São Francisco Valley, Brazil. The experiment was conducted in a randomized block design, in two crop cycles, with three replications, with ten treatments consisted of three controlled water deficits (15%, 30%, and 45% of the crop evapotranspiration - ETc), applied at three development stages of the plant - sprouting and tillering (Stage I), grand growth (Stage II), and maturation (Stage III) - and a control with 100% of the ETc throughout the entire crop cycle. The controlled water deficit did not affect the technological quality of the sugarcane in any development stage. The sugarcane yield was higher when using a controlled water deficit of 30% of ETc in the sprouting and tillering stages of the plants. The water deficit of 15% of ETc is recommended for the grand growth, or maturation stages of the sugarcane plants for a greater water use efficiency of the production system.


2019 ◽  
Vol 40 (2) ◽  
pp. 731
Author(s):  
Natan Teles Cruz ◽  
Braulio Maia de Lana Sousa ◽  
Jailson Lara Fagundes ◽  
Alfredo Acosta Backes ◽  
José Dantas Gusmão Filho ◽  
...  

This study was undertaken to examine the herbage accumulation dynamics and structural characteristics of digit grass subjected to different defoliation frequencies in the period of January 2015 to February 2016. Four defoliation frequencies [very high (25 cm), high (35 cm), medium (45 cm), and low (55 cm)] were evaluated in two periods of the year [greater insolation (September to March) and lesser insolation (April to August)]. The experiment was set up as a randomized-block design with four replicates. Overall, the decreasing defoliation frequencies increased the cutting interval; leaf area index; total-herbage, stem, and dead-herbage accumulation rates; and percentages of stems and dead herbage. This reduction in defoliation frequency also resulted in a lower leaf accumulation rate and percentage of leaves. In overall terms, digit grass showed higher total-herbage, leaf, and stem accumulation rates; percentages of stems and dead herbage; stem volume density; and tiller density in the period of greater insolation. In the period of lesser insolation, however, digit grass exhibited a lower dead-herbage accumulation rate and a lower percentage of dead herbage. Less frequent defoliations increase the herbage accumulation rates of digit grass, but result in a less desirable morphological composition.


2019 ◽  
Vol 40 (3) ◽  
pp. 1317
Author(s):  
Jaqueline Rocha Wobeto Sarto ◽  
Marcela Abbado Neres ◽  
Caroline Daiane Nath ◽  
Doglas Bassegio ◽  
Marcos Vinicius Mansano Sarto

Tropical soils are highly weathered, acidic, and low in silicon (Si) availability for plants. Si has been considered an essential nutrient for many grasses. Urochloa Convert HD364 is classified as a forage plant that accumulates Si, but the accumulation of this nutrient in the leaf can influence qualitative characteristics, fiber quality, plant architecture, and development of forage. In this study, we aimed to evaluate the production and nutritive value of Urochloa hybrid cultivar Convert HD364 (CIAT 36087) grown from soils collected in the state of Paraná, Brazil. The experiment was carried out in a greenhouse using 8-L plastic pots and three types of soil. Treatments were arranged in a randomized block design in a 3 × 5 factorial: three soils [Rhodic Acrudox (Ox1), Rhodic Hapludox (Ox2) and Arenic Hapludult (Ult)] and five silicate rates (0, 1, 2, 4 and 6 Mg ha-1 of calcium/magnesium silicate), with four replications. Application of CaSiO3 to the soil increases the concentration of Si in the leaves of Urochloa Convert HD364. The dry matter, crude protein and mineral matter, fiber quality, and digestibility of Urochloa were not influenced by the increase in Si levels in the leaves until 45 days after seeding. Forty-five days after planting, CaSiO3 did not interfere with the growth characteristics and production of Urochloa Convert HD364. There is no evidence that the increased Si levels in the leaf affected the production and nutritive value, especially fiber quality of Urochloa Convert HD364 until 45 days after sedding.


2018 ◽  
Vol 39 (6) ◽  
pp. 2517
Author(s):  
Armindo Neivo Kichel ◽  
Luis Carlos Ferreira de Souza ◽  
Roberto Giolo de Almeida ◽  
José Alexandre Agiova da Costa

This study aimed to assess productivity and nutritional value of the tropical grasses Brachiaria brizantha cv. Piatã, Xaraés, and Marandu, Panicum maximum cv. Mombaça, and B. ruziziensis cv. Kennedy in the interseason of an integrated crop-livestock (ICL) system since alternatives are needed for forage production for animal grazing in Autumn and Winter. The experimental design was a randomized block design in a split-split plot scheme with four replications. The treatments of plots consisted of five grasses, subplots consisted of three cropping systems (monoculture, intercropping with corn and unsuppressed grass, and intercropped with corn and suppressed grass), and sub-subplots consisted of four cutting intervals of grasses (50, 90, 125, and 195 days after emergence - DAE). The experiment was carried out from February to September 2014. Dry matter (DM) productivity, obtained at 195 DAE for the three cropping systems (monoculture grass, unsuppressed and suppressed grass in intercropping), were 18.45, 7.15, and 3.05 t ha?1, respectively, and average crude protein contents of leaf blades of grasses decreased linearly between the cutting intervals of 50 to 195 DAE from 19.95 to 9.70%, respectively. Under integrated systems, the studied grasses showed better yields and nutritional quality when compared to traditional grazing systems. Panicum maximum cv. Mombaça and Brachiaria brizantha cv. Xaraés and Piatã had the highest leaf and crude protein yields when compared to Brachiaria ruziziensis cv. Kennedy and Brachiaria brizantha cv. Marandu. In terms of nutritional value, Brachiaria ruziziensis cv. Kennedy was superior to Mombaça and Xaraés grasses but had lower total dry matter yield. Finally, Xaraés, Piatã and Mombaça grasses are recommended choices ICL systems when fodder grass production is the goal.


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.


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