Penman–Monteith reference evapotranspiration adapted to estimate irrigated tree transpiration

Pereira, Alfredo; Green, Steve; Nova, Nílson Augusto Villa

doi:10.1016/j.agwat.2005.11.004

Cited by 76 publications

(60 citation statements)

References 40 publications

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“…It is interesting to note that the present results is substantiated by those obtained previously with different plant species such as grapefruit in Israel (Cohen, 1991) (Pereira et al, 2006;Fernández et al, 2008), and Tahiti acid lime in Brazil (Pereira and Villa Nova, 2009). Such results with very distinctive crops show that ET LA becomes independent of plant size and tend to merge in a unique linear relationship of ETo.…”

Section: Resultssupporting

confidence: 77%

“…Such results with very distinctive crops show that ET LA becomes independent of plant size and tend to merge in a unique linear relationship of ETo. Indeed there was a very narrow range of the regression coefficients (0.34 to 0.36) for each tree (Pereira et al 2006;Pereira and Villa Nova, 2009).…”

Section: Resultsmentioning

confidence: 99%

“…Another important aspect to observe is that the empirical regression coefficients discussed above can be derived theoretically if it is assumed that the water use per unit leaf area of the irrigated trees (ET LA ) is equal to the reference evapotranspiration (ETo) also expressed per unit leaf area of the reference surface (Lo), i.e., ET LA = ETo/Lo Pereira et al, 2006). The reference surface was defined by Allen et al (1998) as a hypothetical grass field with constant Lo = 2.88.…”

Section: Resultsmentioning

confidence: 99%

“…Micrometeorological changes due to the canopy growth are discussed to support such inference. As recommended elsewhere (Pereira et al, 2006;Fernández et al, 2008) in order to become an operational tool in real-time precision irrigation schemes it is necessary an easy way to estimate plant leaf area. Simple empirical relationships between plant leaf area and planting rate or canopy volume interpreted to substantiate the discussion and to define thresholds.…”

Section: Methodsmentioning

confidence: 99%

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Coffee crop coefficient for precision irrigation based on leaf area index

Pereira¹,

Camargo

Nova³

2011

Bragantia

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Crop coefficient (Kc) for coffee plantations was found to be linearly related to the leaf area index (L) up to 3, i.e., Kc = b L. The basic assumption is that for irrigated trees the water use per unit leaf area (ET LA) is equal to the reference evapotranspiration (ETo) expressed also on a unit leaf area basis of the reference surface (ET LA = ETo/Lo). As recommended by FAO-56 the leaf area index (Lo) for the hypothetical reference surface (grass) is equal to 2.88, then the most likely value is b = Lo-1 = 2.88-1 = 0.347. However, for L > 3 (completely covered ground surface) Kc decreased from a peak value (~1.05) tending to an asymptotic low value around 0.7 for L > 6, but the linear model gives unrealistic Kc estimates; tentatively the empirical function Kc = 1.8 L-0.5 is offered here as an initial guess due to the lack of experimental results for the interval 3.5 <L < 5.5. To become operational under commercial fields it is necessary to estimate the leaf area per coffee tree (LA, m² tree-1), and based on a very limited set of data, LA was estimated as a function of planting density (PD, trees ha-1), i.e., LA = 88.38 - 8.63 Ln (PD). Alternatively, L (< 3.4) can be computed directly as a function of canopy volume (for V < 1.2 m³).

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Section: Resultssupporting

confidence: 77%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Coffee crop coefficient for precision irrigation based on leaf area index

Pereira¹,

Camargo

Nova³

2011

Bragantia

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“…Para a estimativa de ET o em condições de campo, o método de Penman-Monteith, padronizado como recomendado por Allen et al (1998), é utilizado como padrão por diversos pesquisadores (Garcia et al, 2004;Katerji & Rana, 2006;Pereira et al, 2006). Em cultivos protegidos, entretanto, a velocidade do ar está, em geral, abaixo de 0,5 ms -1 na maioria das instalações, mesmo com a utilização de ventilação mecânica (Hanan, 1998).…”

Section: Estimativa Do Coeficiente De Culturaunclassified

Coeficiente de cultura da alface hidropônica baseado no conceito de graus-dia

et al. 2010

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Degree-day-based crop coefficient for hydroponic lettuceThe main objective in this work was to propose the adoption of a thermal crop coefficient by using accumulated degree-days after transplanting to estimate lettuce daily evapotranspiration (ET c ) for the cultivars Grand Rapids, Regina and Great Lakes in a NFT hydroponic system under protected environment. Subsequently, the adjusted model to the observed values of K c was used for estimating ET c during the growing period after transplanting with the following methods: Penman-Monteith parameterized by FAO in 1998 (PMF); Penman-Monteith modified for aerodynamic characteristics in protected environment (PMAP); simplified Penman-Monteith (PMAPS); Priestley-Taylor (PT); solar radiation (RS); and simplified solar radiation (RSS). It was verified that the sigmoid model with four parameters fitted well to observed values of K c ,giving adjusted coefficients of determination of 0,9874, 0,9784 and 0,9767 for cultivars Grand Rapids, Regina and Great Lakes, respectively. As far as daily ET c estimates are concerned, the methods PMF, PMAP and RS presented better statistical performance as compared to the methods PMAPS, PT and RSS, regardless of the evaluated cultivar. However, the method PMF systematically underestimated ET c in the lettuce initial growth period. Coeficiente de cultura da alface hidropônica baseado no conceito de graus-dia O objetivo principal deste trabalho foi propor a adoção de um coeficiente de cultura térmico, com a aplicação do conceito de graus-dia acumulados após o transplantio, para estimativa da evapotranspiração diária (ET c ) dos cultivares de alface Grand Rapids, Regina e Great Lakes em sistema hidropônico do tipo NFT ("nutrient film technique"), em ambiente protegido. Posteriormente, o modelo matemático ajustado aos valores observados de K c (coeficiente de cultura) foi utilizado para a estimativa de ET c no período pós-transplantio por meio dos métodos: Penman-Monteith parametrizado pela FAO, em 1998 (PMF); Penman-Monteith modificado para condições aerodinâmicas, características de ambientes protegidos (PMAP); Penman-Monteith para ambiente protegido simplificado (PMAPS); Priestley-Taylor (PT); Radiação solar (RS); e Radiação solar simplificado (RSS). Verificou-se que o modelo sigmoidal com quatro parâmetros ajustou-se bem aos valores observados de K c , proporcionando coeficientes de determinação ajustados de 0,99, 0,98 e 0,98 para os cultivares Grand Rapids, Regina e Great Lakes, respectivamente. No que se refere às estimativas diárias de ET c , os métodos PMF, PMAP e RS apresentaram melhor desempenho estatístico em relação aos métodos PMAPS, PT e RSS, independentemente do cultivar avaliado. No entanto, o método PMF subestimou sistematicamente a ET c no período inicial de crescimento da alface.Palavras chave: Cultivo protegido, tempo térmico, técnica de circulação laminar de nutrientes.

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The influence of climate and management on transpiration of residential trees during a bark beetle infestation

Litvak,

Pataki

2024

Ecosphere

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Trees in residential environments are affected by a unique combination of environmental and anthropogenic factors, including occasional insect outbreaks that are increasing in frequency and severity due to climate change. We studied loblolly pine trees infested by bark beetles in a residential backyard in a southeastern US city. We investigated the responses of tree and stand‐level transpiration to environmental factors (solar radiation, atmospheric vapor pressure deficit, and soil moisture), severe weather events (strong winds and heavy storms), bark beetle infestation, and human actions (insecticide treatments and tree removals). We used constant heat dissipation probes to make continuous sap flux measurements (J0) in tree boles. Over 22 months of the study, J0 of trees with confirmed infestation decreased from ~90 to ~60 g cm−2 day−1 and J0 of the rest of the trees increased from ~60 to ~80 g cm−2 day−1. One infested tree died, as its J0 steadily declined from 110 g cm−2 day−1 to zero over the course of 2 months, followed by a loss of foliage and visible signs of severe infestation 6 months later. J0 was sensitive to variations in incoming solar radiation and atmospheric vapor pressure deficit. In most trees, J0 linearly responded to soil water content during drought periods. Yet despite complex dynamics of J0 variations, plot‐level transpiration at the end of the study was the same as at the beginning due to compensatory increases in tree transpiration rates. This study highlights the intrinsic interplay of environmental, biotic, and anthropogenic factors in residential environments where human actions may directly mediate ecosystem responses to climate.

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Penman–Monteith reference evapotranspiration adapted to estimate irrigated tree transpiration

Cited by 76 publications

References 40 publications

Coffee crop coefficient for precision irrigation based on leaf area index

Coffee crop coefficient for precision irrigation based on leaf area index

Coeficiente de cultura da alface hidropônica baseado no conceito de graus-dia

The influence of climate and management on transpiration of residential trees during a bark beetle infestation

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