Growth, yield, and quality of hot pepper (Capsicum annuum L.) as affected by the combined application of liquid bio-slurry and NPS fertilizer rates in Kucha, Gamo zone, south Ethiopia

Hot pepper (Capsicum annuum L.) is a key cash and nutritional crop in Ethiopia, yet its productivity remains constrained by inadequate and imbalanced soil nutrient management. Therefore, the field experiment was conducted in Kucha woreda, Gamo Zone, South Ethiopia, during the 2024/25 cropping season to investigate the effect of liquid bio-slurry and NPS fertilizer rates on growth, yield and quality of hot pepper. The experiment consisted of 16 treatments arranged in a factorial combination of four liquid bio-slurry (LBS) rates (0, 20, 40, and 60 m3 ha−1) and four NPS fertilizer rates (0, 75, 150, and 225 kg ha−1) using a randomized complete block design with three replications. All experimental data were collected following standard agronomic procedures and subjected to analysis of variance using GenStat statistical software (18th edition). The results revealed that both the main and interaction effects of liquid bio-slurry and NPS significantly (p < 0.01) influenced phenological, growth, yield, and quality parameters. The combined application of 150 kg ha−1 NPS and 60 m3 ha−1 LBS produced the highest marketable dry fruit yield (2.94 t ha−1) and total dry fruit yield (3.16 t ha−1), representing a 129.69% yield advantage over the control (1.28 t ha−1) in the case of marketable dry fruit yield. The findings demonstrate that integrated nutrient management using combined LBS and NPS fertilizers significantly enhanced the productivity and quality of hot pepper. Therefore, the application of 150 kg ha−1 NPS combined with 60 m3 ha−1 liquid bio-slurry is recommended for improved hot pepper production for the study area and similar agro-ecological conditions.