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Kremer,Cristián; Stöckle,Claudio. |
Transpiration-use efficiency (w), defined as the ratio of biomass produced per unit water transpired, has been used to evaluate crop performance under limited water supply. However, the lack of consistency of w values through different environmental conditions has not allowed, using it as a transferable parameter. Thus, simple approaches have been developed, including: 1) w = kDa Da¹ and; 2) w = kEto ETo-¹ where kDa and kETo are crop-dependent parameters, with the underlying concept that normalization by Da or ET0 would accounts for the effects of climate variations on w, while these parameters would be reasonably constant across diverse environments. The objective of this study was to assess the transferability of kDa and kET^0 for wheat... |
Tipo: Journal article |
Palavras-chave: Transpiration-use efficiency; Models of biomass production. |
Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392012000100002 |
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Oyarzún,Ricardo; Stöckle,Claudio; Wu,Joan; Whiting,Matthew. |
In many crop models, the process of radiation transmittance through the canopy is normally described as an exponential attenuation process (Beers Law equation), which is assumed to be valid for canopies covering the ground with a random spatial distribution of leaves. However, for discontinuous canopies, where a distinctive row pattern of plant exists, there is a more complex situation because of the presence of gaps between individual plants. This must be accounted for when characterizing radiation relationships for these kinds of systems, in particular when short time-scales are of interest. Photosynthetically active radiation (PAR) transmittance (τPAR) is more commonly studied and reported than global solar radiation (Sg) transmittance... |
Tipo: Journal article |
Palavras-chave: Radiation interception; Extinction coefficient; Crop simulation model. |
Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392011000100015 |
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