Production of commercial branches of roselle with organic and mineral fertilization and plant architecture pruning

Abstract

Roselle (Hibiscus sabdariffa L.) cultivation in tropical and subtropical regions is carried out by family farmers without the use of technology and with low yields. This study aimed to evaluate the use of organic and mineral fertilizers in roselle growth and nutrition in São Luís, State of Maranhão, northeastern Brazil. The experiment was conducted in a randomized block design in a factorial scheme [(7x2)+1]. The treatments consisted of seven doses of poultry litter (0.0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 L), six percentages of NPK (100.0, 83.3, 66.3, 49.9, 33.2, and 16.5%), and an additional treatment (poultry litter plus PK at maximum doses), with three replications. Split harvests were conducted at 75, 105, 135, and 165 days after transplanting. Fresh phytomass and the number of primary, secondary, and commercial branches were evaluated in each harvest. Fertilization with poultry litter increased fresh biomass production and the number of commercial branches per plant. Phytomass and the number of commercial branches decreased with an increase in the cutting interval in the split harvests. The poultry litter enhanced the efficiency of mineral fertilization in crop management, standing out the combination of 1.0 L poultry litter plant-1 plus 66.3% of the recommended NPK dose.