Evaluación del vigor vegetal de Alnus acuminata Kunth (Aliso) aplicando dos métodos no destructivos: índice normalizado diferencial de vegetación (NDVI) e índice de robustez (IR).

Abstract

This research aimed to evaluate the plant vigor of alder (Alnus acuminata Kunth), applying two non-destructive methods to determine plant vigor: Normalized Difference Vegetation Index (NDVI) and Robustness Index (IR), in the nursery of the Escuela Superior Politécnica de Chimborazo, Riobamba city; at 15, 30 and 45 days after the application of fertilizers. To confirm the alder's plant vigor, three dosages of nitrogen (N), phosphorus (P), potassium (K) fertilizers were applied and control, using Randomized Complete Block Design (RCBD). The data of height and diameter at the root collar (DAC) of the seedlings and the images allowed to determine the IR and NDVI indexes. For the statistical analysis, the General Invariant Linear Model and Tukey's test were used at 5%, obtaining, as a result, that the IR does not show significant difference at a statistical level between treatments; and in the evaluation of NDVI statistically, there are crucial differences between treatments. It was corroborated with the Tukey test at 5% showing four groups, the T3 = NPK 18-46-0, showed better response to the assimilation of nutrients with NPK, therefore with the highest value of NDVI at the end of 45 days. It is concluded that NPK fertilizers in different dosages, used to evaluate the vegetal vigor of Alnus acuminata Kunth, show favorable response in the IR and NDVI indexes results while the optimization of the time and resources used for the evaluation will depend on the objective and the number of seedlings to be evaluated. It is recommended to specify the leaf area to be studied, either basal or apical and to use soluble or liquid fertilizers for fertilization. In the specific case of Alnus acuminata Kunth, it is suggested to extend the evaluation time.