EFFECT OF CONTROLLED RELEASE FERTILIZERS ON GROWTH OF TEAK PLANTS (Tectona grandis) ON NURSERY

Abstract

Teak (Tectona grandis L. f.) occupies 74 % of the area planted with tropical hardwoods in the world, and it is the most important cultivated species in this category. Mexican companies are interested in multiplying this species and compete in the international market by producing quality plants. Fertilization is, after irrigation, the cultural practice that most directly influences plant growth at the nursery. In this study, the growth of teak seedlings was evaluated when grown for two months in 310 cm³ containers filled with a mix of vermiculite, perlite and peat moss. The substrate mix included Basacote® Plus (16N-08P-12K) 9M, Osmocote® Plus 12M (15N-9P-12K) and Multicote® 8M (18N-6P-12K) in four dosages: 0 (control), 10 (low), 20 (medium) and 30 kg m^-3. Treatments were compared under a completely randomized experimental design with three replications. Variables measured included shoot diameter, collar height, shoot and root biomass, robustness index (RI), ratio of aerial biomass to root biomass (BA/BR), and Dickson quality index (DQI). Seedlings fertilized with Osmocote at medium and high dosages showed the highest increase in all morphological variables; however, the highest quality plants, according to the RI, BA/BR and DQI indexes, were those fertilized with Basacote at any of the threel doses, and those fertilized with Osmocote at the lowest dose.