The effects of cultivation time, local organic substrates and their weight on smallholder urban oyster mushroom production in Zimbabwe

This study aimed at assessing the effect of cultivation time, local substrates and their weight on urban smallholder oyster mushroom production in Zimbabwe. The study was carried out in a low cost urban mushroom growing house and laid out in a randomized complete block design with each treatment replicated four times. Substrate type was highly significant (p<0.01) on days to fruiting, mean number of mushroom, mean mushroom weight and biological efficiency. Evaluation of different substrates for cultivation of oyster mushroom revealed that among the different substrates, wheat straw was superior which recorded minimum days to fruiting (16.62 days), maximum number of mushroom heads (106.25), maximum average yield per 3 months (4826.63g) and highest biological efficiency of 66.88%. Wheat straw accelerated the mushroom growing process having the lowest duration of days to fruiting. The mycelia completed colonization, primordium initiation and fruiting body formation were found within 16.62±0.69, 22.75±0.69, 26.88±0.69 and 31.00±0.69 days for wheat straw, hay, maize stalk and groundnut hulls, respectively. Wheat straw was found to have the highest biological efficiency (66.88±4.59) followed by hay (41.88±4.59), groundnut hull (40.00±4.59) and maize stalk (39.88±4.59). However, the biological efficiency decreased with increase in substrate weight per bag, and substrate weight did not influence the days to fruiting.