EFFECT OF DIFFERENT SUBSTRATES AND THEIR COMBINATIONS ON GROWTH RATE AND YIELD PERFORMANCE OF OYSTER MUSHROOM ( Pleurotus ostreatus), IN WOLDIA, NORTH WOLLO, ETHIOPIA

This research examined the effect of various substrate compositions on the growth rate and yield 
performance of oyster mushroom (Pleurotus ostreatus) under controlled conditions at Woldia 
University, Ethiopia. Given the national need for sustainable, low-input food sources amid 
rising food insecurity, the study addresses a critical gap in knowledge regarding optimal 
substrate utilization using locally available materials such as teff straw, grass straw, and 
sawdust. A completely randomized design with seven treatments and three replications was 
employed. Significant differences (p < 0.05) were found among treatments for key variables 
including colonization period, pinhead formation, stipe length, cap diameter, number of fruiting 
bodies, total fresh yield, and biological efficiency. The highest total yield (530.87 g) and 
biological efficiency (53.09%) were recorded in the substrate mixture of 33.3% teff straw, 33.3% 
grass straw, and 33.3% sawdust. This treatment also produced the most consistent regrowth 
across three flushes. In contrast, the 50% sawdust + 50% teff straw treatment yielded the lowest 
biological efficiency (49.03%). Substrate composition significantly influenced cap diameter 
(ranging from 2.87 to 7.73 cm) and number of fruiting bodies (9–26 per flush), indicating that 
blended substrates optimize physical structure and nutrient availability. These findings 
underscore the importance of strategic substrate formulation to enhance mushroom productivity 
and support food security initiatives through cost-effective, environmentally friendly cultivation 
systems.