Integrated Use of Low Cost Materials with Traditionally Used Sawdust in Oyster Mushroom (Pleurotus Ostreatus) Cultivation in Sri Lanka.

Abstract

Although several alternative substrates have been introduced, Sri Lankan Oyster mushroom (Pleurotus ostreatus) farmers rely only on sawdust. Currently, there is difficulty in finding traditionally used sawdust as they are used in other industries. Therefore, a study was conducted to cut off the traditionally used mango sawdust (MSD) requirement by combining low-cost natural materials such as Guinea grass (Panicum maxima) leaves (GL) and paddy husk (PH), and another potential sawdust - teak sawdust (TSD). The experiment was designed as a Complete Randomized Design (CRD) with eight substrates; T1: 100% MSD (Control), T2: 50% MSD + 50% PH, T3: 25% MSD + 75% PH, T4: 50% MSD + 50% GL, T5: 25% MSD + 75% GL, T6: 100% TSD, T7: 75% MSD + 25% TSD, T8: 50% MSD + 50% TSD. All the treatments comprised the substrate (30 kg), rice bran (3 kg), mungbean flour (300 g), Calcium oxide (600 g), and Magnesium Sulphate (60 g). Among the substrates evaluated, T1 showed the highest mycelium growth rate (6.83 mm/day), while T7 showed the lowest (5.78 mm/day); T3 spent a minimum duration for primordia initiation (07 days) and first harvest (10 days from the bag opening and 39 days from the inoculation); T7 showed the highest cap diameter (8.07 cm) which is statistically similar to all other treatments except in T3 (7.47 cm); and T4 showed the highest dry weight (46.18 g/kg) and the fresh weight (561.07 g/kg) of harvested mushroom. The biological efficiency was significantly higher in T4, T5 and T2, and it was significantly lower in T7, T6 and T8 than the control. Therefore, incorporation of guinea leaves or paddy husk would be effective to reduce the amount of traditionally used mango sawdust in Oyster mushroom cultivation. Further, Teak sawdust would not as effective as traditionally used mango sawdust.