Application of Trichoderma viride immobilized on rice husk under reduced synthetic fertilization in yellow chili pepper (Capsicum baccatum L.) var. pendulum

Abstract

Introduction: The intensive use of synthetic fertilizers in horticultural crops generates economic and environmental impacts, particularly in already degraded soils. Sustainable strategies are therefore required to reduce mineral fertilizer inputs without compromising crop productivity. This study evaluated the effect of an organic amendment containing Trichoderma viride immobilized on rice husk as a strategy to reduce mineral fertilization in yellow chili pepper (Capsicum baccatum L.) var. pendulum. Methods: Four treatments were evaluated in a completely randomized block design with three replications: T1 (complete fertilization with 200:66:42 kg ha⁻¹ N:P:K), T2 (135:48:21 kg ha⁻¹ N:P:K without organic amendment), T3 (135:48:21 kg ha⁻¹ N:P:K plus organic amendment at 0.5 kg plant⁻¹), and T4 (organic amendment only). Crop variables (height, chlorophyll index, root depth, fruit number, yield, and dry matter) were evaluated. Results: Full fertilization (T1) increased plant height and showed a slight tendency toward higher chlorophyll index and fruit number values. However, yields under reduced fertilization (T2 and T3) were statistically similar to T1, indicating that mineral fertilization could be reduced by 30% without significant yield penalties under the evaluated conditions. The addition of the organic amendment in T3 did not significantly increase yield compared with T2, but promoted greater dry matter allocation to leaves, stems, and roots, suggesting a potential positive effect on vegetative development. Discussion: The results indicate that reducing mineral fertilization in yellow chili pepper is feasible without compromising productivity. The incorporation of T. viride immobilized on rice husk may represent a complementary strategy for agroecological transition while promoting the recycling of agro-industrial residues. Nevertheless, because the findings derive from a single growing season, multi-year studies are required to validate these results and to assess long-term effects on soil properties, microbiota dynamics, commercial scalability, and economic viability.