Two-stage environmental management during fruiting supports higher first-flush premium-grade yield in Pleurotus geesteranus

Environmental requirements differ across developmental stages of Pleurotus geesteranus , making consistent total and premium-grade production difficult under fixed conditions. We developed a two-stage programme that switched environmental settings when stipes of approximately 50% of fruiting bodies reached 3–4 cm. In March 2025, the programme was implemented in a digital smart mushroom fruiting chamber (DSMFC) and compared concurrently with three reference environments; three additional DSMFC batches assessed consistency. The DSMFC attained a first-flush yield of 304.2 g bag − 1 , biological efficiency of 46.7%, and 82.2 fruiting bodies bag − 1 , all higher than in the reference environments. Premium-grade (grades I and II combined) fresh weight and proportion were 139.36 g bag − 1 and 46.0%. The higher yield was characterised by more harvested fruiting bodies and higher grade I fresh weight, not increased individual grade II fresh weight. Grade II mushrooms from the DSMFC had longer, thinner stipes; temperature was negatively associated with stipe length, and CO 2 concentration was negatively associated with stipe diameter. Across four DSMFC batches, coefficients of variation for batch means of first-flush yield, premium-grade fresh weight, and proportion were below 5%. The stipe-length criterion provides a practical trigger for standardised fruiting management.