EFFECT OF SUBSTRATE OF MOTHER SPAWN ON CONTAMINATION AND YIELD OF OYSTER MUSHROOM (Pleurotus ostreatus)

Abstract

The experiment was carried out during the period from November 2020 to March 2021 to find out the effect of substrate of mother spawn on contamination and productivity of oyster mushroom (Pleurotus ostreatus). Nine different treatments were used as viz. T 1 = Mustard; T 2 = Red maize; T 3 = 50% rice straw and 50% sawdust; T 4

= Millet; T 6 = Gram; T 7 = Pea; T 8 = Rice and T 9 = White maize. The experiment was laid out in single factor Completely Randomized Design (CRD) with replications. The highest mycelium running rate of mother spawn (0.85 cm/day) was observed when the rice grain was used. The minimum duration required from incubation to completion of mycelium running of mother spawn (16.33 days) and maximum mycelium weight (4.08) was observed in rice. The minimum duration required from incubation to completion of mycelium running in yield packets (18.33), from stimulation to primordial initiation (5.89 days), from primordial initiation to 1st harvest (5.67 days) and the lowest total harvesting period (40.00 days) were found when mother spawn of rice was used. Again, the maximum number of primordia (87.33), effective fruiting body per packet (31.00), the highest length of pileus (5.17 cm) and width of pileus (7.49 cm) were found at mother spawn of rice. Oyster mushroom grown on sawdust substrates where mother spawn of rice inoculated gave the highest biological yield (175.67 g), economic yield (168.33 g) and biological efficiency (35.13%). During the cultivation period four contaminants namely Trichoderma sp. Penicillium sp, Rhizopus stolonifer and Aspergillus niger were isolated and identified from contaminated substrates. Percent contamination of fungi gradually increased with the increase of days after stimulation. After 45 days after stimulation (DAT), packets inoculated with rice and wheat mother spawn were not contaminated. Among the treatments, the performance of mother spawn of rice was better economically as well as growth and yield performance for the cultivation of oyster mushroom.