Comparative cultivation of Agaricus bisporus and A. bitorquis on cocoa pod husk–rice bran blends

Abstract High ambient temperatures and the cost of compost limit button mushroom production in the tropics. This study compared Agaricus bisporus with the thermotolerant congener A. bitorquis on cocoa pod husk (CPH)–rice bran blends under tropical conditions, across seven substrates spanning unsupplemented CPH through progressively rice-bran-enriched blends, an optimized agro-waste mix, and a straw–cow dung compost, to a commercial compost benchmark, with three replicates per species-substrate combination. The primary practical finding is that a simple 3:1 CPH: rice-bran blend (no composting step) recovered about three-quarters of commercial-compost biological efficiency with roughly 70% less contamination, at an estimated 40–60% of commercial substrate cost. This A. bitorquis strain colonized substrates faster than the A. bisporus strain on every substrate and out-yielded it throughout (strain-, not species-, level comparisons; see Limitations), though the advantage varied unevenly across the gradient rather than tracking substrate richness. Supplementing CPH with rice bran at a 3:1 ratio nearly doubled biological efficiency relative to unsupplemented CPH and cut contamination by roughly 70% in both strains, recovering about three-quarters of commercial-compost biological efficiency without any composting step. The optimized agro-waste mix performed better still, and commercial compost remained the ceiling. Across the substrate gradient, faster colonization and lower contamination were strongly associated with higher yield and biological efficiency, pointing to colonization speed and sanitation as practical levers for production. Mushrooms grown on the 3:1 blend were nutritionally favorable, with crude protein of 30–34% dry weight and elevated potassium and magnesium, and A. bitorquis exceeded A. bisporus in protein content. CPH–rice bran blends, particularly at a 3:1 ratio, are viable, input-light, reproducible substrates for cocoa-region Agaricus cultivation, with the A. bitorquis strain tested the more robust of the two for non-composted, warm-climate production.