Modelagem estatística de características biométricas para cultivares de macieira pouco exigentes ao frio cultivadas no Norte do Estado do Espírito Santo

Abstract

The exploitation of apple cultivars (Malus domestica Borkh) with little cold demand has shown great potential for the diversification of agricultural crops in tropical regions. Among the cultivars that stand out, we can mention Eva, Julieta and Princesa, who have good productivity and fruit quality. However, these cultivars need more studies that allow a better knowledge of their physiological patterns to understand their behavior over the years, which are fundamental characteristics for the management of culture. In this context, the use of mathematical models allows to relate characteristics that are difficult to measure with characteristics that are easy to measure, obtaining simple and precise equations that estimate these characteristics in a non-destructive way. In view of the need to understand the growth patterns of apple culture in tropical regions, two experiments were developed. In the first experiment, the objective was to study the modeling of the leaf area of three apple cultivars, Eva, Julieta and Princesa, looking for a single regression equation that could represent the three cultivars. For this experiment, a total of 900 leaves were used, divided between the adjustment of the modeling and the validation from which 36 equations were obtained to estimate the cultivar area individually and two equations to estimate the area of the three cultivars together in which they combined the averages of the actual leaf area of the leaves with the measures of their length, width and their respective combinations. Thus, it was possible to conclude that the model equation power the leaf area as a function of the product of the multiplication of the length with the width (LW) represented by ELA = 0.8119LW-../01 it presented greater precision in relation to the other models obtained, being the most adequate to estimate the leaf area of the cultivars of apple tree Eva, Julieta and Princesa together, quickly, safely, easily and non-destructively. In the second experiment, the objective was to generate mathematical model equations in order to estimate non-destructively the mass of apple fruits of the cultivars Eva, Julieta and Princesa from the dimensions of length and width. For this, 390 fruits (130 of each cultivar) were measured, obtaining the measures of length (L), diameter (D) and observed mass (OM), these characteristics were related giving rise to first degree and power linear model equations. After validation, it was found that it was not possible to adjust a single model to meet the three cultivars. Thus, the mass of the apple fruits can be predicted, in a non-destructive way, by the power model through the greater width of the fruits by the equation EM = 0.0064D6.0/1- for cultivating Eva, EM= 0.0054D6.8-9: for cultivating Julieta and EM = 0.0041 D6.8/9; for cultivating Princesa. If necessary, the power model equation EM = 0.0051D6.89:- can be used to estimate together the mass of cultivars Julieta and Princesa from the largest diameter