Use of Paspalum Viginatum as an Alternative Growth Substrate for Oyster Mushroom Cultivation

Abstract

The increasing demand for mushroom consumption worldwide calls for alternative growth substrates to ensure sustainable production. The study was conducted to evaluate the use of Paspalum vaginatum straw as an alternative growth substrate for the cultivation of oyster mushrooms (Pleurotus ostreatus), and to assess the effect of the growth substrate on the nutritional composition of the mushrooms. Six substrates were evaluated for the growth of the mushrooms. These were 100% Paspalum straw, Paspalum + sawdust (1:1), Paspalum + 5% rice bran, Paspalum + 10% rice bran, Paspalum + 20% rice bran, and 100% sawdust. The diameter of the mushroom cap, length of the stalk, total number and weight of fruiting bodies harvested were recorded. Proximate analysis was conducted to determine the moisture content, crude protein, total carbohydrates, fat, crude fibre, ash, Iron, Zinc, Calcium, Potassium, and Sodium contents of the mushrooms. The results indicated that the substrates significantly (p<0.01) influenced the number of days to first harvest, the size of the mushroom cap and the length of the stalk. The total number and weight of fruiting bodies harvested from the various substrates were not significantly different (p<0.05). This indicates that the yield of oyster mushrooms cultivated on the Paspalum was comparable to that of the sawdust which is widely used. The various substrates significantly affected the nutritional composition of the oyster mushrooms. Out of the six growth media, mushrooms cultivated on Paspalum straw substrate had the highest protein (61.3%) and Na (0.65mg) contents, but low in fat (0.1mg) and carbohydrates (14%). The mushrooms cultivated on sawdust recorded the highest fat content (0.59mg), Fe (10mg), Zn (6.9 mg) and Ca (0.77mg). Since the performance of the Paspalum in terms of the parameters studied were comparable to the sawdust, which has been the main substrate used for mushroom production, it can be concluded that P. vaginatum is a promising alternative substrate for the mushroom industry. The use of Paspalum for mushroom cultivation will reduce the dependence on sawdust.

Keywords: Oyster mushroom, Paspalum grass, Substrate, Yield, Proximate, Nutrients.