Equações para a estimativa do índice de área foliar do cafeeiro

Favarin, José Laércio; Neto, Durval Dourado; García, Axel García y; Nova, Nílson Augusto Villa; Favarin, Maria da Graça Guilherme Vieira

doi:10.1590/s0100-204x2002000600005

Cited by 117 publications

(107 citation statements)

References 1 publication

(1 reference statement)

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“…oleifera) is a cold-season oilseed plant cultivated in Southern Brazil (Krüger, 2011). Its yield is influenced by different environmental, physiological and morphological factors, among which leaf area (LA) is a parameter indicative of crop yield, since biomass accumulation occurs through photosynthesis and the leaf is the main plant organ, responsible for gas exchanges and light energy interception (Pereira et al, 1997;Favarin et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Non-destructive models for leaf area determination in canola

Tartaglia

Righi

Rocha

et al. 2016

Rev. bras. eng. agríc. ambient.

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A B S T R A C TThe leaf is a very important structure of the plants, since it allows gas exchanges and the transformation of light energy into chemical energy. This study aimed to generate and test mathematical models for leaf area estimation in canola based on leaf dimensions. Two experiments were conducted with canola in 2014, in which leaves were collected in different phenological stages with different sizes and shapes. Subsequently, leaf length, width and area were measured (with automatic meter) in 606 leaves, which included 371 ovate and 235 lanceolate leaves. The models were generated using length, width and length versus width as independent variables and leaf area as dependent variable. The models were validated using a group of leaves different from those used to generate the models. A total of 27 models were obtained and those with best statistics and higher simplicity were selected. The polynomial model LA = 0.88735 W 2 + 0.93503 W and the power model LA = 1.1282 W 1.9396 can be used for both types of leaves and have high accuracy in the estimation of canola leaf area.Modelos não destrutivos para determinação da área foliar em canola R E S U M O A folha é uma estrutura de grande importância para as plantas, visto que por meio dela ocorrem as trocas gasosas e a transformação da energia luminosa em energia química. O objetivo neste trabalho foi gerar e testar modelos matemáticos para a estimativa de área foliar de folhas de canola em função das dimensões foliares. Para isto foram realizados dois experimentos com canola no ano de 2014 e coletadas folhas em diferentes estágios fenológicos e de diferentes tamanhos e formas; posteriormente foram medidos o comprimento, a largura e a área foliar (com medidor automático) de 606 folhas dentre as quais 371 ovaladas e 235 lanceoladas. Os modelos foram gerados utilizando-se comprimento, largura e comprimento versus largura como variáveis independentes e a área foliar como variável dependente. Os modelos foram validados com um grupo distinto de folhas dos utilizados para a geração. Obteve-se o total de 27 modelos escolhendo-se aqueles que apresentaram as melhores estatísticas e maior simplicidade. Os modelos que podem ser utilizados para ambos os tipos de folhas e apresentam alta precisão de estimativa de área foliar em canola, são o modelo polinomial AF = 0,88735 L 2 + 0,93503 L e o modelo potencial AF = 1,1282 L 1,9396 . Key words:Brassica napus ovate leaves lanceolate leaves modeling Palavras-chave:Brassica napus folhas ovaladas folhas lanceoladas modelagem

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Section: Introductionmentioning

confidence: 99%

Non-destructive models for leaf area determination in canola

Tartaglia

Righi

Rocha

et al. 2016

Rev. bras. eng. agríc. ambient.

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“…A quantifi cação da área foliar de uma cultura é importante em estudos de crescimento, uma vez que a fotossíntese realizada depende da interceptação da energia luminosa pelo dossel e da sua conversão em energia química (FAVARIN et al, 2002). Para a quantifi cação da área foliar, existem métodos diretos e indiretos de estimação da área foliar.…”

Section: Introductionunclassified

Estimação da área foliar de feijão guandu por dimensões foliares

Filho

Toebe²,

Alves³

et al. 2015

Cienc. Rural

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RESUMO O objetivo deste trabalho foi modelar e identifi car os melhores modelos para a estimação da área foliar de feijão guandu, determinada por fotos digitais em função do comprimento, ou da largura e/ou do produto comprimento vezes largura do limbo do folíolo central da folha. Foram conduzidos dois experimentos com a cultura de feijão guandu. No primeiro experimento, foram realizadas coletas de 200 folhas aos 45, 52, 59, 65, 72, 79, 86, 94, 100, 106 45, 52, 59, 65, 72, 79, 86, 94, 100, 106 and 114

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“…Barbosa et al (2012), when estimating LAI, found that the variability of the shape of crowns and the geometry of leafless regions were the properties that most strongly explained coffee's LAI. Also working with coffee, Favarin et al (2002) …”

Section: Resultsmentioning

confidence: 99%

“…The productive performance of a crop can be assessed throughout its growth by monitoring the plant leaf area (Sanpedro et al 2008), as the photosynthetic process depends on the interception of photosynthetically active radiation and its conversion capacity into chemical energy (Favarin et al 2002, Godoy et al 2007). …”

Section: Introductionmentioning

confidence: 99%

Indirect methods for determining the area index of forage cactus cladodes

Pinheiro

Silva

Diniz

et al. 2015

Pesqui. Agropecu. Trop.

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Methods for determining leaf area index have been applied to various agricultural crops. However, their uses are limited to broadleaf plants, with no record for forage cactus, whose radiation interception is performed by the cladode. This study aimed to evaluate the use of different indirect methods to estimate the area index of forage cactus cladode. Cladodes from clones of Nopalea cochenillifera Salm Dyck, Nopalea cochenillifera Salm Dyck and Opuntia stricta (Haw) Haw were used, being sampled sixty plants per clone, distributed in five sub-areas with 12 plants. Light interception methods with different measurement techniques were evaluated, as well as the planimetric, leaf discs and modeling methods. The estimate of area index of the forage cactus cladode by the modeling method was considered the most accurate one, for presenting precision coefficient values and accuracy above 0.90, as well as a performance varying from very good to excellent. However, its applicability depends on the use of estimated parameters or adjusted value equations. The methods of light interception and its derivations, leaf discs of medium cladodes and planimetry of medium cladodes are not recommended, due to their low precision and accuracy.

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Equações para a estimativa do índice de área foliar do cafeeiro

Cited by 117 publications

References 1 publication

Non-destructive models for leaf area determination in canola

Non-destructive models for leaf area determination in canola

Estimação da área foliar de feijão guandu por dimensões foliares

Indirect methods for determining the area index of forage cactus cladodes

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