Estimação da área foliar de canola por dimensões foliares

Abstract

ResumoO objetivo deste trabalho foi modelar e identificar os melhores modelos para a estimação da área foliar determinada por fotos digitais, de três híbridos de canola, em função do comprimento, ou da largura e/ou do produto comprimento vezes largura do limbo foliar. Foram conduzidos três ensaios de uniformidade com canola (Brassica napus L.), e em cada ensaio avaliou-se um dos seguintes híbridos: Hyola 61, Hyola 76 e Hyola 433. Em cada híbrido, foram coletadas 125 folhas aos 77, 84, 91 e 97 dias após a semeadura, totalizando 1.500 folhas. Nessas 1.500 folhas, foram mensurados o comprimento (C) e a largura (L), e calculado o produto do comprimento vezes a largura (C×L) do limbo foliar. Determinou-se a área foliar de cada folha, por meio do método de fotos digitais (Y). Posteriormente, para cada híbrido, foram separadas, aleatoriamente, 80% das folhas (100 folhas por coleta × 4 coletas por híbrido = 400 folhas por híbrido) para a geração de modelos do tipo quadrático, potência e linear, de Y em função do C, da L, e/ou do C×L. Os 20% das folhas restantes (100 folhas por híbrido) foram usadas, separadamente, para a validação dos modelos. Em canola, os modelos do tipo potência, para os híbridos Hyola 61 (Ŷ = 1,3000x , R 2 = 0,9613), são adequados para a estimação da área foliar determinada por fotos digitais (Y) em função da largura do limbo foliar (x).Palavras-chave: Brassica napus L., fotos digitais, modelagem, método não destrutivo. Leaf area estimation of canola by leaf dimensions AbstractThe objective of this work was to model and identify the best models to estimate the leaf area determined by digital photos, of three canola hybrid, with the length or width and / or the product length width of the leaf. Three uniformity trials were carried with the culture of canola (Brassica napus L.). In each trial was valued one of the following hybrids: Hyola 61, Hyola 76, Hyola 433. In each hybrid were collected 125 leaves at 77, 84, 91, 97 days after sowing, totaling 1,500 leaves. In these 1,500 leaves were measured length (C) and width (L) and calculated the length width (C×L) of the leaf. Was determined the leaf area of each leaf, by the method of digital photos (Y). After, for each hybrid were separated, randomly, 80% of the leaves (100 leaves by collects × 4 collects by hybrid = 400 leaves per hybrid) to build models of quadratic, potency and linear type for Y function of the C, L and/or C×L. The remaining 20% of the leaves (100 leaves by hybrid), separately, were used to validate the models. In canola, the potency model for hybrid Hyola 61 (Ŷ = 1.3000x

Non-destructive models for leaf area determination in canola

“…In tests conducted with the equations of Cargnelutti Filho et al (2015) for Hyola 61 and Hyola 433, with the equations specific for the LA of these cultivars, there was underestimation of more than 10% in the estimated values of LA compared with those in the present study. On the other hand, the general power equation (Model 2) showed deviations in the 1:1 tendency of at most 4% when the cultivars were separated, which demonstrate the capacity for LA estimation of mixed leaves of the power model developed in the present study.…”

“…The coefficients of the models obtained in the present study for four different cultivars were close to those obtained by Cargnelutti Filho et al (2015) individually for three cultivars, indicating that one single model can be used for the different canola cultivars under the climatic conditions of Santa Maria-RS.…”

“…Additionally, Chavarria et al (2011) also used leaf length (L) as independent variable. However, the variable with highest correlation with canola leaf area when a general model is used is leaf width (W), which is corroborated by the results of Cargnelutti Filho et al (2015).…”

“…For the canola crop, there are the models of Chavarria et al (2011) and Cargnelutti Filho et al (2015). However, applying only one model to determine canola leaf area may not be adequate, because the leaves are morphologically different along its development (Iriarte & Valetti, 2008) and one model for each cultivar becomes unviable, since new cultivars are frequently released.…”

Leaf Area Estimate of Erythroxylum simonis Plowman by Linear Dimensions

“…Regarding the data variability, lower variation coefficients were registered for the linear dimensions of width and length (CV = 33.13 and 34.14%, respectively), and greater variability for the product (LxW) and leaf 4/7 Ribeiro JES, Barbosa AJS, Albuquerque MB Floresta e Ambiente 2018; 25(2): e20170108 area (CV = 63.37 and 62.62%) ( Table 2). Other studies also presented greater variability for LxW regarding the L and W dimensions (Cargnelutti et al, 2012(Cargnelutti et al, , 2015Toebe et al, 2012). Table 3 presents the percentage distribution of the 200 E. simonis leaf blades regarding their size range.…”