ABSTRACT

 The study was aimed at determining the productivity, growth pattern and proximate compositions of Pleurotus ostreatus cultivated on Andropogon gayanus (AND) supplemented with Gmelina arborea (GML). Data obtained from these were subjected to ANOVA in a Completely Randomized Design (CRD) and replicated three (3) times for the various substrate supplementations. AND 100%, AND 80% + GML 20%, AND 70% + GML 30%, AND 60% + 40%, AND 50% + GML 50%. There was no significant differences' (P<0.05) in the various analysis carried out except in the result of Proximate analysis where the values showed significant difference at P>0.05. The productivity was determined on the basis of the weight, stipe length and pileus diameter. The fruit-bodies had the highest (3.62cm) weight at the AND I 00% level and the least (2.62cm) at AND 50% + GML 50% supplementation. The AND 100% had the highest (4.46cm) value for the stipe length and the least (3.18cm) at the AND 50% + GML 50% supplementation: The AND 60% + GML 40% supplementation had the highest (4.28cm) pileus diameter and the AND 100% had the least (2.95cm). The growth pattern had the highest (141g) yield at AND 50% + GML 50% and a Biological Efficiency (B.E) of 53.5% while the least (55g) was obtained at AND 60% + GML 40% supplementation and B.E of 32.0%. The values of the proximate compositions of the fruit-bodies of Pleurotus ostreatus cultivated on A. gayanus supplemented with G. arborea varied. The values ranged from 33.60% of protein in AND 100% to 28.00% in AND 50% + GML 50% supplementation, with the fat content increasing from 2.40%% at AND 100% to 3.20% at AND 50% + GML 50% supplementation as the supplementation level increased. The crude fibre contents of the fruit-bodies decreased from 16.00% at AND 100% to 12.10% at AND 50% + GML 50% supplementation. The ash contents of the fruit-bodies decreased from 9.80% at AND100% to 7.50% at AND 50% + GML 50%. The moisture contents of the fruit-bodies varied with an irregular differences amongst them with the AND 100% having the highest (8.40%) moisture value and the least (7.45%) from AND 50% + GML 50%. The carbohydrate contents of the fruit-bodies also increased supplementation level increased. The AND 50% + GML 50% had the highest (41.75%) carbohydrate value and AND100% had the least (29.80%).