Crescimento inicial de mudas de cumbaru em resposta à adubação nitrogenada

Nitrogen fertilization can be a necessary activity in a seedling production nursery, especially when substrates capable of providing the nutrientsin the quantities and time that the plants need are not used. Among the native species that are commonly produced in nurseries is the cumbaru (Dipteryx alata), used in forest restoration projects, however, whose nutritional demands still need to be elucidated. Therefore, the objective of the present studywas to evaluate the initial growth of cumbaru (D. alata) seedlings in different N doses and to recommend the most favorable. The experiment was carried out in a completely randomized design with five N doses and five replications, using urea as N source. The doses tested were: T0 –without addition of N; T1 –50 mg dm-3; T2 –100 mg dm-3; T3 –150 mg dm-3; T4 –200 mg dm-3. At the end of 90 days, the morphological characteristics were evaluated to qualify the cumbaru seedlings. There was no difference between the means for the morphological characteristics studied. However, a trend towards improvement in the growth and development of D. alataseedlings was observed, with the addition of 150 mg dm-3 of N, tothe substrate.