Modeling Leaf Area Estimation for Arabica Coffee (<i>Coffea Arabica</i> L.) Grown at Different Altitudes of Mana District, Jimma Zone

Abstract

This study was aimed at establishing allometric models for estimating LA (Leaf Area) of eight Coffea arabica genotypes in Mana district of Jimma Zone Oromia Regional State, South Western Ethiopia (7˚46'N, 36˚0'E). Many Methodologies and instruments have been devised to facilitate measurement of leaf area. However, these methods are destructive, laborious and expensive. For modeling leaf area, leaf width, leaf length and leaf area of 1200 leaves (50 leaves for each genotype) was measured for model calibration and the respective measurements on 960 leaves were used for model validation. Linear measurement was taken from leaves and branch diameters of eight genotypes of C. arabica, cultivated in field following a randomized complete blocks design at three altitudes (High, Medium and Low) were evaluated to identify best option for input in the models, and to validate the method to estimate the leaf area. Linear and non-linear models were tested for their accuracy to predict leaf area of the eight C. arabica genotypes. The use of linear model resulted in high accuracy for all of the eight C. arabica genotypes. No significant effect of growing altitude and genotype was obtained among the slopes of the models. Therefore, one single model was fitted to the combined data of all genotypes at all altitudes (LA = 0.6434LW). Comparison between observed and predicted leaf area was made using this model in another independent dataset, conducted for model validation, exhibited a high degree of correlation (r = 0.98 -0.99, P < 0. 01). The over or under estimation of the leaf area using this model ranges between 0.02% to 1.7% and this model is adequate to estimate the leaf area for the eight C. arabica genotypes. Hence, this model can be proposed to be reliably used and with this developed model, researchers can estimate the leaf area of newly released eight genotypes of C. arabica at different altitudes accurately.

Allometric relationships between leaf and bulb traits of Fritillaria przewalskii Maxim. grown at different altitudes

“…They are particularly important for species that grow in harsh or unstable habitats, like F. przewalskii. Leaves have essential roles in plant physiology and long-term adaptation to environmental changes [19]. Leaf and bulb morphology and biomass accumulation are fundamental plant functional traits.…”

Estimation of Leaf Area by Linear Dimensions in Coffea dewevrei

“…However, considering these two equations, the quadratic model presented values of mean absolute error (MAE) and root mean square error (RQME) closest to zero, in addition to the value of the index d closest to the unit, which suggests a more predictive leaf area of Coffea dewevrei by this model. Notoriously, several authors have reported in the literature models of mathematical equations that estimate the leaf area of several coffee varieties [15,18,29,16]. In specific cases, the model adjusted for a given variety can be used to estimate leaf area of other varieties [30].…”

“…However, the indirect and nondestructive methods allow successive evaluations in the same plant and rapidity in the evaluations [12], and are therefore more convenient and cheaper [13]. In the indirect methods, portable automatic planimeters are used, sometimes with the disadvantage that the larger leaves cannot be evaluated by limiting the reading area of the portable equipment [14], it is still used mathematical models, using leaf blade length and width [12], to which they generally involve the use of regression equations, as in Coffea arabica coffee trees [15,11,16], and Coffea canephora [17,15,18], however, in the literature there is no evidence of studies with Coffea dewevrei, therefore, it is important to obtain them, since it is known that temporal variation of leaf area in an agricultural crop depends on cultivar, edaphoclimatic conditions, and population density, among other factors [19].…”

Estimación del Área Foliar y su Relación sobre algunos Caracteres Agro-Morfológicos en Variedades de C. arabica L. en Ángel Albino Corzo, Chiapas, México

“…Los datos obtenidos fueron procesados mediante el paquete estadístico RStudio Team (2020) en donde se realizó un análisis de varianza y prueba de comparación de medias de Tukey a una significancia de p<0.05 (Misgana et al, 2018) además de análisis de multivariado de agrupamiento (Cosme-De La Cruz et al, 2020) para conocer la relación entre las variables sobre el índice de área foliar.…”