Avaliação do desenvolvimento do estipe principal e da produção de palmito, em pupunheiras (bactris gasipaes kunth) submetidas diferentes espaçamentos e formas de adubação mineral e orgânica, na Amazônia Central

Abstract

The present work aimed to evaluate plant development and production of heart-of-palm (palmito) of peach palms under different spacing and forms of mineral and organic fertilization in the Central Amazonia region. This study also aimed to make use of agricultural organic residue, to enhance sustainable agricultural production and to reduce costs of regional agriculture. The experiment was carried out at the Agricultural Jayoro Company Ltd. area in the municipality of Presidente Figueiredo, (AM), Brazil. The experimental design was of randomized blocks with three repetitions following 2 x 5 factorial scheme, being the factors: spacing (1 x 0,5 m and 1 x 1 m) and fertilization (mineral and organic). The treatments consisted of fertilization being the formula 225-90-180 kg.ha-1year-1 of N-P2O5-K2O, being N and K2O in three split plots; mineral fertilization (N and K2O in three split plots + one shovel of manure pit-1 year-1; filter cake of sugar cane (two shovels pit-1 four times a year) and compost (filter cake + guarana bark, two shovels pit-1 four times a year), mineral fertilizer (N and K2O in three split plots) + compost (two shovels pit-1 four times a year). Among the studied variables on plant growth factor in fertilization, the results showed better performance in organic + mineral fertilization at the height of the main plant (115,57 cm), stem diameter (97.10 mm) and number of offshoots (5,50), however there was significant difference between height and diameter at breast height for the two greatest values. Number of green leaves showed the highest values in the treatments with composted manure and filter cake (7.17 and 6.93 leaves, respectively). In relation to spacing, the number of offshoots was the only statistical difference found showing higher number at the density of 1 x 1 m (5.03). A tendency of better performance was observed for the space of 1 x 1 m in relation to stem diameter and leaf number (79.17 mm and 6.89 leaves). The height average values of the main plant showed 82,07 for 1 x 0,5 m spacing and 78,45 cm for the other spacing tested. There was no interaction between factors studied for the variables height, diameter, leaf number and offshoot number. In relation to heart-ofpalm production, the mineral fertilization + manure and mineral + compost treatments showed the highest values of harvested stems, number of heart-of-palm, tender stem and total heart-of-palm l (heart-of-palm + tender stem). The spacing of 1 x 0,5 m showed the best performance in all characters analyzed for heart-of-palm with significant difference for the 1 x 1 m treatment. The results for total dry matter for the factors fertilization and spacing did not present statistical difference, however mineral fertilization had the best effect followed by mineral + manure. Treatment of 1 x 0,5 m showed the best result for density. There was no difference for total leaf area for both fertilization and spacing. Even tough, the compost formulation had best effect followed by mineral + compost. In relation to density, the study of total foliar area showed that 1 x 1 m treatment was the most efficient spacing. Fertilization and spacing made possible first harvesting 15 months after sowing optimizing the precocity of this crop.