Analysis and growth curves fitting of Moringa oleifera Lam. on different substrata

Abstract

There are currently no available growth models for the species Moringa Oleifera in the Mexican tropics. The objective of this research was to analyze seedling growth curves of M. oleifera under greenhouse conditions and six substrates with different nutritional content: sand (A), sandy loam (FA), clay (AC) and sugar cane compost (C) mixed in proportions of A2:C1, A1:C1 and A1:C2. Soil analysis detected Nitrogen contents of 1.5, 1.6, 0.2 and 0% for C, AC, F and A, respectively. Once germinated and during a period of 36 days, length and stem diameter, leaf number, leaf length and width were measured every four days. The resulting groups of curves were compared against three growth models: Chapman-Richards, Gompertz and Logistic. There were significant differences in stem diameter, height and number of leaves between substrate A and the others after 20 days (P < 0.05). Substrates A1:C1 and A1:C2 allowed higher growth rates in height and stem diameter, followed by substrates A2:C1, FA and AC. Logistic and Gompertz were the two models that best fit the growth curves, with coefficients of determination of 0.96 and 0.95, respectively. We conclude that a combination A1:C1 was sufficient to obtain high growth rates in M. oleifera during nursery stage, while Gompertz and Logistic models were able to predict the growth on different substrates.