SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Cruz,Pedro Gomes da; Santos,Patricia Menezes; Pezzopane,José Ricardo Macedo; Oliveira,Patrícia Perondi Anchão; Araujo,Leandro Coelho de.

O objetivo deste estudo foi testar modelos empíricos de regressão linear, para a predição do acúmulo de matéria seca (TAMS) de Urochloa brizantha cv. Marandu, em função de variáveis agrometeorológicas. Para gerar os modelos, foi utilizada a taxa média de acúmulo de matéria seca, em condições de sequeiro, entre 1998 e 2002. As variáveis avaliadas foram: temperaturas mínima, máxima e média, radiação global (Rg), graus-dia, evapotranspiração real (ETR) e potencial (ETP) obtidas a partir do balanço hídrico, unidades fototérmicas (UF) e índice climático de crescimento (ICC). As regressões univariada e multivariada mostraram boa capacidade de predição, com exceção para as que utilizam a UF. Os melhores resultados foram para a regressão multivariada, com Tmín, Rg...

Morphogenetic characteristics and management of Tanzania grass

Palavras-chave: Brachiaria brizantha; Urochloa brizantha; Regressão linear; Regressão multivariada.

Ano: 2011

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2011000700001

Santos,Patricia Menezes; Balsalobre,Marco Antônio Alvares; Corsi,Moacyr.

The objective of this work was to evaluate the effect of grazing interval and period of evaluation over tissue turnover in Tanzania grass pastures (Panicum maximum cv. Tanzania) and to ascertain if herbage accumulation rate can be used as a criterion to establish a defoliation schedule for this grass in Southeast of Brazil. A randomized block design with a split-plot arrangement was used. The effect of three grazing intervals was evaluated within seven periods between October 1995 and September 1996. Responses monitored were leaf and stem elongation rates, leaf senescence rate, stem length, and tiller density. Net herbage accumulation rate was calculated using tissue turnover data. The grazing intervals for Tanzania grass should be around 38 days between...

Climate change and future scenarios for palisade grass production in the state of São Paulo, Brazil

Palavras-chave: Leaves; Elongation; Senescence; Grazing systems.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2003000800012

Andrade,André Santana; Santos,Patricia Menezes; Pezzopane,José Ricardo Macedo; Bettiol,Giovana Maranhão; Evangelista,Sílvio Roberto Medeiros.

The objective of this work was to analyze future scenarios for palisade grass yield subjected to climate change for the state of São Paulo, Brazil. An empirical crop model was used to estimate yields, according to growing degree-days adjusted by one drought attenuation factor. Climate data from 1963 to 2009 of 23 meteorological stations were used for current climate conditions. Downscaled outputs of two general circulation models were used to project future climate for the 2013-2040 and 2043-2070 periods, considering two contrasting scenarios of temperature and atmospheric CO2 concentration increase (high and low). Annual dry matter yield should be from 14 to 42% higher than the current one, depending on the evaluated scenario. Yield variation between...

Dry matter production of Tanzania grass as a function of agrometeorological variables

Palavras-chave: Brachiaria brizantha; Urochloa brizantha; Empirical model; ETA; Precis; Tropical grass..

Ano: 2014

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014001000745

Pezzopane,José Ricardo Macedo; Santos,Patricia Menezes; Mendonça,Fernando Campos; Araujo,Leandro Coelho de; Cruz,Pedro Gomes da.

The objective of this work was to develop and validate linear regression models to estimate the production of dry matter by Tanzania grass (Megathyrsus maximus, cultivar Tanzania) as a function of agrometeorological variables. For this purpose, data on the growth of this forage grass from 2000 to 2005, under dry‑field conditions in São Carlos, SP, Brazil, were correlated to the following climatic parameters: minimum and mean temperatures, degree‑days, and potential and actual evapotranspiration. Simple linear regressions were performed between agrometeorological variables (independent) and the dry matter accumulation rate (dependent). The estimates were validated with independent data obtained in São Carlos and Piracicaba, SP, Brazil. The best statistical...

Critical periods of sorghum and palisadegrass in intercropped cultivation for climatic risk zoning

Palavras-chave: Panicum maximum; Climatic growth index; Degree‑days; Evapotranspiration; Modeling.

Ano: 2012

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000400001

Lima,Nino Rodrigo Cabral de Barros; Santos,Patricia Menezes; Mendonça,Fernando Campos; Araujo,Leandro Coelho de.

The objective of this work was to define critical periods for sorghum and palisadegrass cultivated on crop-livestock integrated systems under water deficit. An experiment was carried out in a completely random block design with four treatments (control and interruption of water supply in three periods) and three replicates. Water supply was interrupted until soil water humidity was close to permanent wilting point at the phases: germination of palisadegrass seeds; start of tillering of palisadegrass and initiation of panicles of shorghum; start of shorghum flowering. Water deficit starting at palisadegrass germination delayed intital development of the plants because of the reduction in tillering. Water restriction at panicle initiation phase and at...

Composição química e fracionamento do nitrogênio e dos carboidratos do capim- Tanzânia irrigado sob três níveis de resíduo pós-pastejo

Palavras-chave: Abiotic stress; Brachiaria brizantha; Crop-livestock integrated systems; Drought.

Ano: 2011

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982011000700008

Balsalobre,Marco Antonio Alvares; Corsi,Moacyr; Santos,Patricia Menezes; Vieira,Ivan; Cárdenas,Ramiro Ruiz.

Amostras simulando o pastejo de capim-Tanzânia (Panicum maximum Jacq.) irrigado sob três resíduos pós-pastejo (baixo, médio e alto) foram coletadas ao longo de um ano e analisadas para a determinação da composição protéica e dos carboidratos, e das frações protéicas e de carboidratos (CNCPS). O teor de NDT foi calculado. Não foi encontrada diferença entre os tratamentos ao longo do ano. Os maiores teores de fibra em detergente neutro - FDN (68,3 a 64,5%) e fibra em detergente ácido - FDA (34,89 a 33,18%) ocorreram no período de primavera/verão. A lignina apresentou maiores proporções no inverno (4,68 a 4,10%), o que provocou variação na fração C dos carboidratos (14,14 a 23,21% dos carboidratos totais). O NDT variou entre 55,26 e 59,31%. O teor de PB...

Response mechanisms of Brachiaria brizantha cultivars to water deficit stress

Palavras-chave: Carboidrato; Cornell; NDT; Panicum maximum; Proteína.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982003000300003

Santos,Patricia Menezes; Cruz,Pedro Gomes da; Araujo,Leandro Coelho de; Pezzopane,José Ricardo Macedo; Valle,Cacilda Borges do; Pezzopane,Cristiana de Gaspari.

Two cultivars of Brachiaria brizantha (Hochst ex. A. Rich) Stapf. (Syn. Urochloa) were evaluated for their adaptation to water deficit and the stress response mechanisms in a greenhouse experiment. The experimental design was in completely randomized blocks with a 2 × 2 × 4 factorial arrangement. The Marandu and BRS Piatã cultivars were evaluated under two water availability conditions, with or without water restriction. The harvests were carried out 0, 7, 14 and 28 days after the start of water restriction. For both cultivars, the water deficit stress caused a reduction in shoot biomass and leaf area and an increase in the percentage of roots in the deeper soil layers. The B. brizantha cv. Marandu reached critical levels of leaf water potential in a...

Descrição botânica de linhagens puras selecionadas de guandu

Palavras-chave: BRS Piatã; Marandu; Osmotic potential; Water availability; Water potential.

Ano: 2013

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013001100001

Provazi,Milena; Camargo,Lívia Haik Guedes de; Santos,Patricia Menezes; Godoy,Rodolfo.

Este estudo foi desenvolvido com o objetivo de realizar a descrição botânica de 11 linhagens de Cajanus cajan. Os principais descritores foram: hábito de crescimento, altura de plantas (cm), número de ramos, diâmetro do caule (mm), cor básica da flor, cor básica da vagem, cor das sementes, cor em volta do hilo das sementes, largura do hilo e forma das sementes. Os descritores utilizados mostraram-se suficientes para caracterizar as linhagens com características distintas, pelas quais podem ser facilmente identificadas.

Características morfogenéticas e taxa de acúmulo de forragem do capim-Mombaça submetido a três intervalos de pastejo

Palavras-chave: Avaliação de forrageira; Cajanus cajan; Descrição botânica; Leguminosa forrageira tropical.

Ano: 2007

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982007000200008

Santos,Patricia Menezes; Balsalobre,Marco Antonio Alvares; Corsi,Moacyr.

O objetivo deste trabalho foi avaliar características morfogenéticas e taxa de acúmulo de forragem em pastos de capim-Mombaça submetidos a três intervalos de pastejo (28, 38 e 48 dias) entre outubro de 1995 e setembro de 1996. O delineamento experimental foi de blocos ao acaso com arranjo em parcelas subdivididas no tempo. Foram avaliadas as taxas de alongamento e senescência foliar, a taxa de alongamento das hastes, a densidade populacional de perfilhos e a altura do pasto. Essas informações permitiram estimar a taxa de acúmulo líquido de matéria seca. A taxa de alongamento de hastes e folhas seguiu comportamento estacional, sendo mais elevada nos meses de maior temperatura e precipitação. A taxa de senescência foliar foi maior com 48 dias de intervalo de...

Adaptation of the C4 grass Panicum maximum to defoliation is related to plasticity of N uptake, mobilisation and allocation patterns

Palavras-chave: Panicum maximum; Perfilhamento; Taxa de alongamento; Taxa de senescência.

Ano: 2004

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982004000400004

Scientia Agricola

Santos,Patricia Menezes; Thornton,Barry; Corsi,Moacyr.

Dry mass production and persistence of Panicum maximum pastures depends on nitrogen supply. Defoliation influences N uptake and allocation patterns yet its effects on plasticity of N dynamics in P. maximum have not been investigated. Stable isotopes of N (15N) were used in order to test the hypothesis that defoliation in terms of proportion of the leaf area removed effects N mobilisation, uptake and allocation patterns in P. maximum. The plants were initially cut weekly to a height of either 0.15 m or 0.30 m for seven weeks. Eight weeks after the first defoliation, all plants were defoliated for a final time to remove 0, 25, 50, 75 or 100 % of the area of each individual leaf blade of the main tiller. Root N uptake was reduced when all leaf area was...

Key factors that influence for seasonal production of Guinea grass

Palavras-chave: Clipping height; Guineagrass; Organic reserves; Regrowth; Tropical grass.

Ano: 2012

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162012000500002

Scientia Agricola

Araujo,Leandro Coelho de; Santos,Patricia Menezes; Rodriguez,Daniel; Pezzopane,José Ricardo Macedo.

ABSTRACT: Climate, soil and management are the main drives for growth and production of tropical pastures. Thus, a better understanding of the effects of these factors and their interactions under climate conditions is required to obtain effective management options. Here, we used data from two field trials to research on climate and management interactions on the production seasonality of Panicum maximum Jacq. Treatments included four sampling times (250, 500, 750, and 1000 °C accumulated) during eight regrowth period, under irrigated and rainfed conditions and, cuts were made to simulate grazing intensity. All treatments were arranged in a completely randomized block design with four replications. At each sampling time, basal tillers were sampled to...