RESPONSE OF ROSELLE (Hibiscus sabdariffa L.) TO POULTRY MANURE AND NPK FERTILIZERS AT SAMARU, NORTHERN GUINEA SAVANNA

Two years field trials were conducted during the 2021 and 2022 seasons in the Institute for Agricultural Research (IAR) farm, Samaru (11o 11/N, 7o 38/E, 686m above sea level) in Kaduna State in the Northern Guinea Savanna ecological zone of Nigeria in order to evaluate the response of Roselle to poultry manure and NPK fertilizer levels. The treatments consisted of four poultry manure rates: 0, 2, 4 and 6 t/ha (tonnes per hectare), then four rates of NPK 20:10:10 fertilizer: 0, 300, 600, and 900 kg/ha (kilogram per hectare). The treatment factors were laid out in a Randomized Complete Block Design (RCBD) and replicated three times. The research results obtained shows that poultry mature application rate of up to 6 t/ha (115:82:61 N:P2O5:K2O kg/ha) significantly increased seed weight per capsule and capsule weight per plant, while application of 4 t/ha (77:55:41 N:P2O5:K2O kg/ha) significantly increased plant height, number of leaves, number of seeds per capsule, seed yield per hectare, and capsule yield per hectare. The result also shows that the application of 300 kg/ha of NPK 20:10:10 (60:30:30 N:P2O5:K2O kg/ha) significantly increased plant height, number of leaves per plant, number of seeds per capsule, seed weight per capsule, seed yield per hectare, capsule weight per plant, and capsule yield per hectare. Based on the study findings, poultry manure application rate of 4 t/ha (77:55:41 N:P2O5:K2O kg/ha), or NPK 20:10:10 application rate of 300 kg/ha (60:30:30 N:P2O5:K2O kg/ha) is recommended for Roselle production.