Evaluation of wheatstraw, sawdust, banana fronds,maize cobs and cotton hulls substratecombinations for Pleurotus ostreatus cultivation.

Abstract

The yield and quality of oyster mushroom is largely dependent on the chemical and nutritional content ofthe substrate. The objective of the study was to determine the effect of different individual substratesand substrate combinations on the perfomance of P.ostreatus for growth and sustainable developmentof the mushroom cultivation industry in Zimbabwe. Various individual substrates used as treatments,selected for the cultivation of oyster mushrooms were, wheatstraw, cotton hulls, sawdust, maize cobsand banana fronds each of 1kg and replicated 4 times. Various substrate combinations, also used astreatments were, cotton hulls and wheatstraw, cotton hulls and sawdust, cotton hulls and maizecobs,cotton hulls and banana fronds in the ratio 1:1. Each combination weighed 1kg and was replicated 4times.Compound substrates perfomed much better in terms of biological effi ciency and spawn runcompared to individual substrates. The highest biological effi ciency (76%) and spawn run(17 days) wereobtained from combining cotton hulls and sawdust. Spawn run was fastest(12 days) for cotton hulls andwheatstraw combination. Analysis in terms of economic return, revealed that mushroom production wasmost profi table using cotton hulls and sawdust as substrate with a benefi t-cost ratio of 5.7 compared toother combinations of agricultural residues. In terms of spawn run, yield and economic return, combiningcotton hulls and sawdust is highly recommended for farmers involved in the cultivation of Pleurotusostreatus to satisfy increasing consumer demand, whilst decreasing pressure on limited naturalresources and preventing ecosystems degradation.