Respostas morfogênicas e estruturais de plantas tropicais submetidas à desfolhação

Barbero, Leandro Martins; Basso, Kelen Cristina; Igarasi, Mauricio Scoton; Paiva, Adenilson José; Basso, Fernanda Gonçalves

doi:10.17523/bia.v72n4p321

Cited by 17 publications

(25 citation statements)

References 19 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Under the lesser PAR incidence, the leaves have less support tissues and mesophyll cells, increasing specific leaf area (Gómez et al, 2013). Similar LAR across faces and distances suggests that Marandu palisadegrass has adaptive mechanisms to improve light use efficiency under limited solar radiation (Barbero et al, 2015).…”

Section: Discussionmentioning

confidence: 98%

Shading Effects on Marandu Palisadegrass in a Silvopastoral System: Plant Morphological and Physiological Responses

et al. 2019

View full text Add to dashboard Cite

The understanding of plant morphological and physiological responses to shading can contribute to developing sustainable silvopastoral systems (SPS). Our objective was to evaluate the shading effect on herbage accumulation (HA), plant‐part composition, physiology, and canopy structural characteristics of Marandu palisadegrass {Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster [syn. Brachiaria brizantha (Hochst. ex A. Rich.) Stapf]} under intermittent defoliation in a SPS with Eucalyptus urograndis (hybrid of Eucalyptus grandis W. Hill ex Maiden and Eucalyptus urophylla S.T. Blake) in Sinop, Mato Grosso, Brazil. The experimental design was a randomized complete block arranged under a strip‐split‐plot, where the plots were allocated to four distances from the Eucalyptus grove (3, 6, 10, and 15‐m) in the SPS, on both faces (north and south), with four replications. The evaluations were done during two summer rainy seasons (RS1 and RS2) and one dry season (DS). The herbage accumulation (HA) in RS1 (4290 kg DM ha–1) was 51% greater than in RS2. The greatest canopy height, light interception, and leaf area index (LAI) values were measured during RS1 (25 cm, 91%, and 3.5 cm2 cm–2, respectively). Leaf photosynthesis rate was less at the 3‐m distance (12.5 μmol CO2 m–2 s–1) than at other distances (17.3 μmol CO2 m–2 s–1). We conclude that Marandu palisadegrass has the ability to physiologically adapt to shaded environments, although the dynamics along the whole tree growing cycle needs to be considered so that grass productivity can be sustained in the long‐term. Core Ideas Longer shading impacted canopy structure and forage accumulation at 3‐m distance. Physiological responses shows reduced light effects on the forage growth pattern. Morphologic composition and sward characteristics were only affected at 3‐m distance. Leaf photosynthesis rate was lesser close to the grove. Silvopastoral systems is an option for livestock production in the Brazilian Amazon.

show abstract

Section: Discussionmentioning

confidence: 98%

Shading Effects on Marandu Palisadegrass in a Silvopastoral System: Plant Morphological and Physiological Responses

et al. 2019

View full text Add to dashboard Cite

show abstract

“…A matéria orgânica contém cerca de 5% de nitrogênio total; por isso serve como uma reserva de nitrogênio. O nitrogênio é o nutriente mais responsivo em práticas de manejo de pastagem (PErEira et al, 2011), pois promove crescimento mais rápido, aumento em número, peso e tamanho de perfilhos e índice de área foliar (BarBEro et al, 2015).…”

Section: Introductionunclassified

Produção e estrutura de pastos de capim-massai adubado com dejetos da produção animal

et al. 2016

View full text Add to dashboard Cite

RESUMO: Objetivou-se avaliar o efeito do uso de adubos orgânicos e mineral na estrutura e na produção de forragem do Panicum maximum cv. Massai. O experimento foi desenvolvido na fazenda escola do Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte, campus Apodi. Os tratamentos avaliados foram fontes orgânicas de nitrogênio (dejetos da suinocultura, da avicultura e da ovinocultura) e uma fonte mineral (ureia), fixados em 150 kg/ha de N. Avaliouse a produção de forragem e de componentes morfológicos, a altura do pasto, a interceptação luminosa, o índice de área foliar e o teor de clorofila, em cortes realizados a cada 60 dias. A altura do dossel foi afetada pelo tipo de adubo aplicado, e maior altura foi observada no pasto adubado com ureia (50,97 cm). A maior interceptação de luz (IL) pelo dossel foi observada nos pastos que receberam ureia, porém não alcançaram 95% de IL. O índice de área foliar nos pastos adubados com ureia foi maior que nos demais, e os valores observados nos pastos que receberam adubos orgânicos foram considerados muito baixos. As massas de forragem, de lâmina foliar, de colmo e de material morto foram afetadas pelo tipo de adubo, e foram maiores nos pastos que receberam ureia. Os teores de clorofila total nas lâminas foliares não diferiram entre os adubos avaliados. A estrutura e a produção de forragem em pastos de capim-massai não são afetadas pelo tipo de dejetos de produção animal utilizado como fonte de nitrogênio. A eficiência destes adubos orgânicos como fonte de nitrogênio é inferior à da adubação mineral. Os dejetos de produção animal avaliados podem ser utilizados como fonte de nitrogênio para pastos de capim-massai em condições de baixo custo e para diminuir os impactos ambientais.Palavras-chave: adubo orgânico, Panicum maximum, ureia. PRODUCTION AND STRUCTURE OF MASSAI GRASS PASTURES FERTILIZED WITH ANIMAL MANURESABSTRACT: The objective of this study was to evaluate the effect of organic and mineral fertilizers on the structure and production of Panicum maximum cv. Massai forage. The experiment was conducted at the teaching farm of Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte, Apodi Campus. The treatments evaluated were organic sources of nitrogen (wastes of pig, poultry and sheep farming) and a mineral source (urea), set at 150 kg N/ha. Forage production, morphological components, pasture height, light interception, leaf area index, and chlorophyll content were evaluated in samples obtained at intervals of 60 days. Canopy height was affected by the type of fertilizer applied and the greatest height was observed for pasture fertilized with urea (50.97 cm). The highest light interception by the canopy was observed for pastures receiving urea, but 95% light interception was not reached. The leaf area index was higher for pastures fertilized with urea compared to the other treatments and the values obtained for pastures receiving organic fertilizers were considered very low. Forage, leaf blade, stem and dead material mass was affe...

show abstract

“…The leaf area index is determined by structural characteristics of the forage canopy (LEMAIRE; CHAPMAN, 1996;BARBERO et al, 2015) such as final leaf length, number of live leaves, tiller density, and leaf-to-stem ratio. Thus, throughout regrowth, as the plant grows and recovers its leaf area, its light interception increases in an attempt to reestablish its photosynthetic capacity (SILVA; NASCIMENTO JÚNIOR, 2007), reaching a maximum value.…”

Section: Resultsmentioning

confidence: 99%

“…These studies have allowed for rational management recommendations to be made in Brazil based on frequencies and intensities of defoliation (SILVA; . Variations in the pasture height established for the entry and exit of animals under a rotational grazing system result in distinct levels of intraspecific competition for light by the forage canopy (CARNEVALLI et al, 2006;ZANINE et al, 2011;BARBERO et al, 2015). This phenomenon can change the accumulation of herbage and its nutritional value, ultimately influencing the feeding behavior and productivity of animals grazing on these forages (PALHANO et al, 2007;VOLTOLINI et al, 2010a, b).…”

Section: Introductionmentioning

confidence: 99%

Herbage accumulation dynamics in digit grass subjected to defoliation frequencies

Cruz

Sousa

Fagundes

et al. 2019

SCA

View full text Add to dashboard Cite

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.

show abstract

Respostas morfogênicas e estruturais de plantas tropicais submetidas à desfolhação

Cited by 17 publications

References 19 publications

Shading Effects on Marandu Palisadegrass in a Silvopastoral System: Plant Morphological and Physiological Responses

Shading Effects on Marandu Palisadegrass in a Silvopastoral System: Plant Morphological and Physiological Responses

Produção e estrutura de pastos de capim-massai adubado com dejetos da produção animal

Herbage accumulation dynamics in digit grass subjected to defoliation frequencies

Contact Info

Product

Resources

About