Performance of Peltophorum dubium under intraspecific tree competition and cardinal directions as possibility for integrated livestock-forestry systems

Peltophorum dubium can be an alternative of forestry species to be included in integrated crop-livestock-forestry systems in tropical region. The aim of this research was to evaluate the performance of P. dubium under intraspecific tree competition and cardinal directions to measure the possibility of introduction in integrated livestock-forestry systems. The experiment was performed in a Nelder Wheel competition, which is used in forestry research to test tree competition. The experimental design was factorial (10×2×5) with 12 replicates. The treatments were accomplished by ten tree competitions (159, 201, 255, 322, 408, 516, 653, 827, 1,046 and 1,324 trees ha-1), two cardinal directions (North-South and East-West) and five times after planting (12, 18, 24, 30 and 36 months). The highest tree competition (1,342 trees ha-1) in 36 months after planting, promoted increase in the cylindrical volume of the tree in both North-South and East-West cardinal directions. Nevertheless, the cardinal direction East-West was profitable to increase tree height, diameter at breast height (DBH), cylindrical volume per tree and cylindrical volume per hectare. The DBH measured in 24 months after planting was 5.0 cm, which is considered the minimum DBH to introduce livestock into the integrated system without significant damage on trees. Regarding these preliminary results in the first three years, P. dubium was promising as Brazilian native species to be inserted in integrated livestock-forestry system or single forestry as an option for Eucalyptus spp. Key words: Forestry, dendrometry, Nelder Wheel, integrated systems, agroforestry