Qualidade de mudas de Pinus taeda L. em resposta à adubação com fertilizantes de liberação controlada

There are several brands of controlled-release fertilizers available on the market, and it is essential to verify their efficiency in producing quality forest seedlings in less time and at a reduced cost. Therefore, the present work aimed to evaluate the use of different controlled-release fertilizers in the production of Pinus taeda seedlings, evaluating their influence on the quality of the seedlings produced. The experimental design used was completely randomized, using the following fertilizers: Osmocote® 18-05-09 (5M) and Basacote® 16-08-12 (+2) (6M). For the composition of the treatments, the following doses were used: T0 - 2.0 kg of Osmocote® + 2.0 kg of Basacote®; T1 - 4.0 kg of Osmocote®; T2 - 4.0 kg of Basacote®; T3 – 3.0 kg of Osmocote® + 1.0 kg of Basacote®; per m3 of substrate. The following were measured: shoot height, root diameter, robustness quotient, shoot dry mass, root dry mass, total dry mass and Dickson quality index. For the production of P. taeda seedlings with a good quality standard, it is recommended to apply 3.0 kg of Osmocote® + 1.0 kg of Basacote® per m3 of substrate. All parameters evaluated were influenced by the fertilizers used.