Fitting growth curves of coffee plants in the nursery stage of growth: A functional approach

Abstract

The growth patterns of coffee plants are determined by interactions between genetic, physiological, and climate factors. The objective of this study was to evaluate the growth patterns of coffee plants in the nursery under the climatic conditions of Chinchiná, Caldas, Colombia, during the first semester of 2019. Measurements were carried out in the Cenicafé 1 variety during six months. Growth parameters such as leaf area, number of leaves, height, stem diameter, and length of the main root were evaluated every 15 d after transplanting (DAT) in 20 plants and the averages of absolute growth (Ĝ) rate of each growth variable were calculated. For the total leaf area, total number of leaves, and stem height, a sigmoidal-type growth curve was adjusted, while the growth curve was linear for the stem diameter (R2 = 0.97) and main root length (R2 = 0.95). Average values were obtained for 520 cm2 for total leaf area, with an Ĝ of 3.31 cm2 d-1, 11 for total leaves (Ĝ 0.055 leaves d-1), 30.23 cm for height (Ĝ 0.155 cm d-1), 4.87 mm for stem diameter (Ĝ 0.199 mm d-1), and 28.80 cm for main root length (Ĝ 0.087 cm d-1) at 180 DAT. These results suggest that growth curves could be a useful tool for describing the growth patterns of coffee seedlings during the nursery stage of growth.

Keywords

• Coffea arabica L.
• nonlinear regression
• goodness of fit
• leaf area
• absolute growth rate