Path analysis of phenological indices of paricá seedlings under different doses of cadmium

Abstract

Paricá (Schizolobium parahyba var. amazonicum) is considered one of the native essences most used in reforestation in the country. The objective is to evaluate the behavior of the phenological indices of paricá seedlings, and identify which ones, directly or indirectly, explain the variability of seedling development; using multivariate statistical methods. Paricá seedlings were used, and after the 16th DAS of acclimation of the seedlings in a nutrient solution, the application of cadmium concentrations began, in the form of cadmium chloride monohydrate (CdCl₂H₂O), at concentrations of 0 (control) mg L^-1; 10 mg L^-1; 20 mg L^-1; 30 mg L^-1 and 40 mg L^-1, in which each concentration corresponded to the treatment, considered in the trail analysis as the main variable. The trail analysis indicated that in the first 60 days of exposure to cadmium, the seedlings grew in height and diameter, chlorophyll A and carotenoids, directly. The attributes seedling height and number of leaves were influenced in a primary, negative way by the cadmium treatment at 80 days, indicating an inverse correlation, that is, with the increase in cadmium dosages culminating in a reduction in height and number of leaves in seedlings. Paricá. Secondary and negative analyzes of the trail analysis highlight that the number of leaflets in the second evaluation, at 80 days, has a significant indirect correlation with height, diameter and number of leaves. This verification is interesting because it shows that a long-term increase in cadmium content (80 days) in Paricá seedlings reduces the number of leaflets in seedlings that showed satisfactory development in height, diameter and number of leaves.