Growth and Yield of Hot Pepper (Capsicum Annuum L.) Varieties in Response to the Integrated Application of Npsb Fertilizer and Municipal-waste Compost at Arba Minch, South Ethiopia

Hot pepper (Capsicum annuum L.) productivity in Ethiopia remains constrained by suboptimal nutrient management and lack of variety-specific fertilizer recommendations. This study evaluated the effects of integrated application of NPSB fertilizer and municipal-waste compost on growth, yield, and yield-related traits of three hot pepper varieties (Melka Shote, Mareko Fana, and Halaba Local) under irrigated conditions at Arba Minch, South Ethiopia. A field experiment was conducted during the 2024 cropping season using a randomized complete block design with a 3 × 5 factorial arrangement and three replications. Treatments comprised five integrated nutrient management strategies: (i) 10 t ha⁻¹ compost (100% organic), (ii) 7.5 t ha⁻¹ compost + 50 kg ha⁻¹ NPSB (75:25), (iii) 5 t ha⁻¹ compost + 100 kg ha⁻¹ NPSB (50:50), (iv) 2.5 t ha⁻¹ compost + 150 kg ha⁻¹ NPSB (25:75), and (v) 200 kg ha⁻¹ NPSB (100% inorganic). Data were subjected under the 'agricolae' package in R software (version 4.4.2).to two-way analysis of variance (ANOVA) following normalization procedures to meet assumptions of homogeneity of variance and normality of residuals. Shapiro-Wilk tests confirmed normal distribution of residuals (W > 0.95, p > 0.05) for all measured parameters after appropriate transformations where necessary. Levene's test verified homogeneity of variances across treatment combinations (p > 0.05). Treatment means were separated using Duncan's Multiple Range Test (DMRT) at p ≤ 0.05 significance level. Results showed that variety × nutrient management interaction significantly influenced most growth, phenological, fruit, and yield parameters (p ≤ 0.05). The Mareko Fana variety under the balanced 50:50 treatment (5 t ha⁻¹ compost + 100 kg ha⁻¹ NPSB) produced the tallest plants (77.78 cm), maximum canopy diameter (62.42 cm), and highest number of primary branches (14.66). Melka Shote under the 25:75 treatment (2.5 t ha⁻¹ compost + 150 kg ha⁻¹ NPSB) achieved the highest number of fruits per plant (119.1), while Mareko Fana with sole NPSB (200 kg ha⁻¹) produced the longest fruits (10.73 cm). For yield, Mareko Fana with sole compost (10 t ha⁻¹) recorded the highest total fresh yield (11.41 t ha⁻¹), whereas the 75:25 treatment (7.5 t ha⁻¹ compost + 50 kg ha⁻¹ NPSB) optimized marketable dry yield (3.46 t ha⁻¹) and total dry yield (4.04 t ha⁻¹) in the same variety. Halaba Local consistently performed poorly across all treatments, confirming its unsuitability for intensive integrated nutrient management. Soil chemical analysis revealed improvements in organic carbon, available phosphorus, and cation exchange capacity under treatments with higher compost proportions, particularly the 75:25 and 100% compost treatments. The integrated application of NPSB fertilizer and municipal-waste compost significantly enhanced hot pepper productivity with highly variety-specific responses. The balanced 50:50 treatment is recommended for optimizing vegetative growth and fruit quality in Mareko Fana and Melka Shote, while the 75:25 treatments maximizes dry matter production for commercial dried pepper markets. These findings underscore the critical need for genotype-specific nutrient management strategies and demonstrate the sustainability benefits of integrating organic amendments for long-term soil fertility maintenance in the Arba Minch irrigation system.