ADJUSTMENT OF NON-LINEAR REGRESSION MODELS TO THE GROWTH OF VEGETABLE LOOF SEEDLINGS (Luffa Cylindrica (L.) M. Roem.)

Abstract

The objective of this work was to adjust mathematical models with four parameters to the growth of loofah seedlings (Luffa Cylindrica (L.) M. Roem.). For this it was necessary to quantify the morphological variables of the crop such as: length of the main branch, number of leaves, diameter of the stem base, leaf area. Furthermore, the correlation between the observed variables and the accumulated degree days (ADD) was determined. The water content and total, fixed and volatile solids content of the aerial part of the crop were also determined. The elemental composition of carbon, hydrogen and oxygen of the aerial part of the crop was estimated. The experiment was conducted under screened nursery conditions with 50% shading. To obtain data, five seedlings were sampled from “each accession” (five replications) every 3 days (72h) until the end of the cycle. Among the adjusted mathematical models, the 4-parameter Sigmoid was the one that presented the highest adjusted R2 for the dependent variables number of leaves and dry mass as a function of the independent variable ADD, 0.937 and 0.870, respectively. The point with the highest crop growth followed by stability in the number of leaves and dry mass was 346.60 ADD.