Doses de pó de basalto no desenvolvimento inicial de mudas de fruteiras nativas da Amazônia

Abstract

The incentive to produce seedlings of native fruits is an important step towards the preservation of species, for their commercial development, generating employment and income for local people. The use of alternative fertilizers such as powdered basalt, allows obtaining a substrate with higher fertility, it is rich in macro and micronutrients, and the slow release of nutrients reduces the cost of manpower and the replacement of fertilization. With the aim of studying the early development of seedlings of native fruit trees to different levels of powdered basalt, we conducted this study at the Experimental Center of Agrarian Sciences, Federal University of Roraima, in a greenhouse. The experimental design was randomized blocks with five replications in a factorial (5x2 +1), 5 doses of basalt powder (0.42, 1.04, 2.08, 4.17 and 8.33 g kg-1), two particle sizes (0.05 and 0.10 mm) and a witness. Vessels were used polyethylene with a capacity of 14 kg, filled with substrate composed of 20% of a Latosol Typic Dystrophic and 80% of vermicompost. We used standard dose 1.04 g kg-1of granite powder and 0.058 g kg-1 of superphosphate as sources of P and K, respectively. The substrate incubation vessel lasted 120 days and thereafter became the transplant seedlings Açaí, Camu-camu and Murici. It was determined the contents and leaf nutrient, height, diameter, number of branches and leaves, the dry matter of shoots and roots, and morphological indices of seedlings. It was concluded that the basalt powder with particle size 0.05 mm resulted in higher levels of Ca, Mg, Fe and Zn, the better cation exchange capacity, lower potential acidity, exchangeable acidity and Al+3 saturation in the substrate. Overall, seedlings of Açaí and Camu-camu subjected to doses with size 0.05 mm showed better growth, seedling Murici of better quality were obtained at doses with coarser grain size.