Autoclave‐Assisted Acidic Extraction of Water‐Soluble Carbohydrates in Forage Grasses

The response of plants to nitrogen fertilization is subject to several factors, including the level of stress caused by defoliation. After defoliation, the plant needs to adjust its energy balance to meet the demands of shoot and root recovery. Our objective was to evaluate the production of forage mass and other morphophysiological responses of zurigrass (Panicum maximum cv. BRS Zuri) subjected to five nitrogen doses (0, 20, 40, 60 and 80 mg/dm3) that were applied at two stages (after the cut and after the appearance of the first leaf on the tiller) under two defoliation intensities (15 and 30 cm of residual height). The pot experiment was conducted in a greenhouse in a completely randomized design with three replications, and the forage mass, as well as other morphophysiological traits, was measured in three regrowth cycles after the first standardization cut. Moreover, to understand the effect of cutting height on the root system, the root mass and root carbohydrate content were evaluated at zero, seven and 14 days after the standardization cut. The root mass reduced after 7 days since cutting under the low residual height (15 cm), but no effects on the root carbohydrate content were observed. The dose of nitrogen had a marked effect on most of the variables analyzed, leading to a linear increase in the root mass, the SPAD chlorophyll content and the harvested forage mass, whereas the number of tillers increased quadratically in response to the nitrogen dose. An increase was observed in the harvested forage mass for plants under the 15 cm of residue treatment compared with those under the 30‐cm treatment (16.0 vs. 13.6 g/pot), but no effect was observed for the time of nitrogen application.

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“…The analysis of the carbohydrate content was performed in accordance with the anthrone method as described by Passos et al. ().…”

Section: Methodsmentioning

confidence: 99%

Productive and morphophysiological responses of Panicum maximum Jacq. cv. BRS Zuri to timing and doses of nitrogen application and defoliation intensity

et al. 2019

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“…In vitro digestible dry matter (IVDDM) was determined by the two-stage procedure of Tilley and Terry 52 modified by Goering and Van Soest 53 . Both stubble and root samples were only analyzed in terms of organic reserves (total N and non-fibrous carbohydrate (NFC)), and NFC was determined according Passos et al 54 . To obtain the pool of nutrients, each component mass was multiplied by its respective nutrient content.…”

Section: Methodsmentioning

confidence: 99%

Spittlebug damage on tropical grass and its impact in pasture-based beef production systems

Congio

Almeida

Barreto

et al. 2020

Sci Rep

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Spittlebugs are the main pest of tropical pastures and Marandu palisade grass (Urochloa brizantha cv. Marandu) is the most representative cultivated pasture in the tropics. Our objective was to characterize Marandu palisade grass responses subjected to Mahanarva (Hemiptera: Cercopidae) attack and to estimate the losses in terms of beef production from pasture-based systems. A set of five experiments were carried out. Three consecutive years of monitoring showed that Mahanarva spittlebugs increased their abundance after first rains with three to four peaks throughout the wet season. A decrease of 66% on herbage yield was observed in the greenhouse trial, with an average decrease of 61% on pools of calcium, magnesium, phosphorus, sulfur, potassium, crude protein, neutral-detergent fiber and in vitro digestible dry matter of Marandu palisade grass. Results from field experiments corroborated with greenhouse trial showing decreases on herbage yield varying from 31 to 43% depending on level of fertilization and grazing severity of Marandu palisade grass. Finally, an unprecedented 154-ha field experiment indicated that Mahanarva decreases 74% the beef productivity (i.e. kg body weight ha −1) of Nellore heifers grazing Marandu palisade grass. Brazil has the largest commercial beef cattle herd and is one of the top beef exporters in the world 1. Brazilian beef represents 20% of all global beef trading and, together with other agricultural commodities, it sums to about 21% of gross domestic product in Brazil 2. Beef cattle production in Brazil is characterized by pasture-based systems of which almost 90% of the cattle slaughtered comes from 3. However, despite highly representative, pasture-based livestock systems are extensive and conducted with low technology inputs resulting in low stocking rates (SR) and animal performance (i.e. average daily gain, ADG). Studies have reported beef production greater than 1,500 kg of body weight (BW) ha year −1 whilst the Brazilian average is much lower at about 150 kg BW ha year −14. Many factors stand out as key drivers for this poor productivity, among them: inadequate grazing management strategies, low soil fertility, and pest damage 5. The 215 million head of cattle in Brazil occupy approximately 160 million hectares composed by 70% of cultivated pasture species and 30% of native grasslands 6,7. Marandu palisade grass {Brachiaria brizantha (Hochst. ex A. Rich.) R. D. Webster [syn. Urochloa brizantha (A. Rich.) Stapf]} is the most representative of the cultivated pasture species, grown in about 50 million hectares in the country 8. It was launched by Embrapa in 1984 as an alternative to signal grass (Brachiaria decumbens cv. Basilisk, syn. Urochloa decumbens Stapf R.D. Webster) owing to its higher herbage yield and, mainly because of its resistance to "pasture spittlebugs" such as Notozulia entreriana (Berg, 1879), Deois flavopicta (Stål, 1854) and Deois schach (Fabricius, 1787) (Hemiptera: Cercopidae) 9. However, from the mid-1990s, spittlebugs from the genus Mahanarva have been r...

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“…Para a determinação da concentração de N foi utilizado o método de combustão de Dumas, com o auxílio do analisador automático de nitrogênio (LECO FP-528) (Wiles et al, 1998). Já as análises de CNE foram realizadas através do método adaptado de silVeira et al (1978) que consiste em extração com HCl em autoclave e determinação através do reagente de Teles (Passos et al, 2006).…”

Section: Methodsunclassified

Rebrota do capim-marandu submetido ao ataque de cigarrinhas

et al. 2012

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RESUMOO objetivo deste experimento foi caracterizar e quantificar respostas de Brachiaria brizantha cv. Marandu sob níveis de infestações de cigarrinhas adultas do gênero Mahanarva (Hemiptera: Cercopidae). O ensaio foi realizado em casa de vegetação na Cidade de Piracicaba, SP, e seus tratamentos corresponderam a quatro níveis de infestações de cigarrinhas (5, 10, 20 e 40 insetos adultos vaso -1 ) mais o controle (sem cigarrinhas), distribuídos nas unidades experimentais (vasos) segundo delineamento inteiramente casualizado. O estudo compreendeu período de infestação pelo inseto e de rebrota das plantas. Avaliaram-se as seguintes variáveis-resposta: acúmulo de forragem, massa de raiz e teor de reservas orgânicas. Não foi observado efeito das cigarrinhas na massa das frações rebrote, resíduo e sistema radicular do capim-marandu (p > 0,05). A massa do resíduo e sistema radicular, assim como a concentração de carboidratos não estruturais nesses órgãos de acúmulo, sofreram influência apenas do período de rebrota (p < 0,0001). Já a concentração de nitrogênio total no resíduo e nas raízes foi influenciada pela interação entre níveis de infestação e período de rebrota (p < 0,0001 e p = 0,0521). PALAVRAS-CHAVE:Brachiaria brizantha, carboidratos não estruturais, Mahanarva, reservas orgânicas, sistema radicular.ABSTRACT REGROWTH OF MARANDU PALISADEGRASS SUBMITTED TO SPITTLEBUGS ATTACK. The objective of this experiment was to characterize and quantify responses of Brachiaria brizantha cv. Marandu under different infestation levels of adult spittlebugs of the genus Mahanarva (Hemiptera: Cercopidae). The experiment was carried out in a greenhouse, in Piracicaba, SP. Treatments corresponded to four spittlebugs infestation levels (5, 10, 20 and 40 adults pot -1 ) plus the control (unifested), distributed in the experimental units (pots) according to a completely randomized design. The study included period of infestation by insects and regrowth of plants. The following response variables were measured: forage yield, root mass and organic reserves. No significant spittlebug effect was observed on regrowth, stubble and root mass of marandu palisadegrass (p > 0.05). The stubble and root mass, as well as the nonstructural carbohydrates concentration, were influenced only during the regrowth period (p < 0.0001). The total nitrogen concentration in stubble and in roots was influenced by the interaction between infestation levels and regrowth period (p < 0.0001 and p = 0.0521).

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Autoclave‐Assisted Acidic Extraction of Water‐Soluble Carbohydrates in Forage Grasses

Cited by 7 publications

References 35 publications

Productive and morphophysiological responses of Panicum maximum Jacq. cv. BRS Zuri to timing and doses of nitrogen application and defoliation intensity

Productive and morphophysiological responses of Panicum maximum Jacq. cv. BRS Zuri to timing and doses of nitrogen application and defoliation intensity

Spittlebug damage on tropical grass and its impact in pasture-based beef production systems

Rebrota do capim-marandu submetido ao ataque de cigarrinhas

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