Estimação da área foliar por método não destrutivo, utilizando medidas lineares das folhas de espécies de Passiflora

Abstract

Estimation of leaf area by non-destructive method using linear measurements of leaves ofPassiflora speciesThe objective of the present study was to develop a reliable equation which enables a fast and non-destructive calculation of leaf area using linear leaf measures from different Passiflora species (P. alata, P. coccinea, P. gibertii, P. ligularis, P. misera, P. mucronata, P. nitida, P. setacea). Three hundred leaves with different sizes were collected from each species. It was performed the analysis of regression of leaf area versus lenght of the main vein, greatest leaf width and their product. Leaf area was measured with a device for automatic measurement and linear measures were determined using a ruler. The linear model chosen for all species, was the one which uses independent variables product because it presents the greatest coefficient of determination (R²) and significative coefficient of regression. The models showed adjusted coefficient of determination higher than 0.927 and optimal performance index, according to the classification of Camargo and Sentelhas. In the process of model validation, it was shown that the correlation between measured leaf area and observed leaf area was very high. The results of this study demostrate that leaf area of Passiflora species can be predicted, using the measurements of the length and width of leaves.

Non-destructive estimation of leaf area in passion fruit (Passiflora edulis L.)

“…Similarly, Morgado et al (2013) reported high coefficients of determination in the generated models (≥ 0.772), and the product between the length and the greatest width was chosen to determine directly and easily the leaf area in lanceolate and trilobed leaves of wild Passiflora species. According to the authors, the leaf area is an important parameter in experimental studies of fruit crops because, according to Spann and Heerema (2010), it can influence photosynthesis, transpiration, and leaf expansion, and it affects the growth rate and the quality of production.…”

“…According to the authors, the leaf area is an important parameter in experimental studies of fruit crops because, according to Spann and Heerema (2010), it can influence photosynthesis, transpiration, and leaf expansion, and it affects the growth rate and the quality of production. With the validation of mathematical models using precise and accurate indices, the equations in the study can be used to measure the area of different morphological patterns of passion fruit leaves quickly, accurately and non-destructively, as also observed by Morgado et al (2013) in obtaining the leaf area of wild Passiflora species.…”

“…Studies related to growth quantitative analysis on passion fruit species that require non-sophisticated equipment (Morgado et al, 2013) enable the assessment of crop production (Souza et al, 2014) and evaluation of biomass accumulation and its partitioning to different plant parts. The evaluation of leaf expansion is important to understand light interception that influences physiological processes related to respiration, transpiration, photosynthesis, use and mobilization of nutrients flowering, fruiting, and crop yield (Silva et al, 2015;Spann and Heerema, 2010).…”

“…Obtaining accurate and easy to perform measurements for determination of leaf area in passion fruit is crucial to understand the effect of the interaction between the crop and the environment on the production processes (Morgado et al, 2013). A number of methods have been developed to estimate leaf area such as direct or destructive methods, comprising the removal of the leaves, and indirect or nondestructive methods, using mathematical models and leaf linear measurements, which facilitates the work in the field (Sachet et al, 2015;Schwab et al, 2014;Tartaglia et al, 2016).…”

“…In passion fruit, indirect models to estimate leaf area were developed for eight wild species (Morgado et al, 2013). However, the species P. edulis was not included in this study.…”