NITROGEN AND POTASSIUM DOSES ASSOCIATED WITH PRODUCTIVITY OF MACAW PLANTS

The macaw fruit stands out as a promising raw material in the oil segment, in a scenario of seeking diversification of sustainable energy sources. Its adaptability and hardiness allow it to be cultivated in marginal agricultural areas, making it an emerging crop. However, measures to ensure uniformity and maximize production efficiency are essential to ensure the sustainability of the production system. The objective of this study was to demonstrate the effect of doses of N and K in adult macaw plants in order to adjust nutritional management. Annual doses of N (42%) plus K (58%) were applied in amounts of 0, 375, 750, 1,125, and 1,500 g plant^-1year^-1, in the 8th, 9th, and 10th year of the plants. The number of spathes, bunches, and fruits, as well as the mass of fruits per bunch and per plant, were evaluated. Doses of maximum physical (MPE) and economic efficiency were also estimated. Data were subjected to variance and regression analyses at 5% probability. The doses of N+K provided significant increases in the analyzed productive characteristics over the three years, except for the average mass of fruits per plant. The application of N and K increased productivity by about 4 times compared to non-fertilized plants. The highest productivity was around 40 kg plant^-1, which was equivalent to 1,083.72 g plant^-1 of N+K in the 10th year. The average productivity of the three harvests was 24.37 kg plant^-1, associated with 471.02 and 780.54 g plant^-1 of N and K₂O, respectively. The dose of 730 g plant^-1year^-1 of N+K was associated with 90% of maximum productivity. A 30% reduction in the MPE dose indicates the possibility of optimizing the nutritional management of macaw, combined with high productivity at lower cost and environmental impact.