The cultivated mushrooms mostly belong to the family Agaricaceae of class Basidiomycetes. Mushrooms may be saprophytic, parasitic and mycorrhizal in their mode of living. Most of the cultivated mushrooms are saprophytic; they feed on organic matter which has already been manufactured by plants or animals. In nature they grow on fallen leaves, animal droppings and stumps of dead wood (Bilgrami & Verma, 1978). In nature mushrooms grow wild in every country from snowy mountains to sandy deserts on all types of soils, pastures, forests, cultivated fields or water lands. They appear in all seasons, chiefly during the rainy weather, wherever organic matter or its decomposition products are available (Kapoor, 1989). Mushroom a food of high quality, flavour and nutrition value have high content of protein, low content of fat (4%), vitamins (B1, B2, C, niacin, biotin etc), minerals (P, Na, K, Ca) and high content of fibers and carbohydrates (Peter, 1991). Mushrooms are also used for chronic catarrh diseases of the breast and hinges, lower the cholesterol level of blood, improves circulation, remedy for night sweating in tuberculosis, rheumatism, gout, jaundice, dropsy, intestinal worms and have anti-tumor, anti-viral and anti-cancer agents.
The most well known species of Pleurotus are P. ostreatus, P. florida, P. eryngii, P. cystidiosis, P. flabellatus, P. cornucopie, and P. sajor-caju. P. sajor-caju is recognized as an excellent mushroom. It can be cultivated within a wide range of temperatures on different natural resources and agricultural wastes. The cultivation of oyster mushroom is simple as compared to other varieties. The mycelial growth variation of six species of Pleurotus at different temperatures was studied by Mehta & Bhandal (1988). The six species were propagated on PDA medium at 10, 15, 20, 25, 30, 35, 40oC. They found that the time taken for complete colonization was 16 days and suitable temperatures were 15, 20, 25 and 30oC while no growth was observed at 10, 35 and 40oC. The sporophores of P. sajor-caju have 26.9 % protein having high digestibility values and all essential seventeen amino acids in good concentration. The five species of Pleurotus cultivated on cotton seed hulls, wheat, rice or maize straw are different in composition of crude protein. Among the substrates, rice straw was best for mushroom growth (Qin et al., 1989). P. sajor-caju can be successfully grown on paddy straw at temperature range of 19.1-30.5oC and relative humidity 65.5-80%, there is a decline in yield above and below this temperature (Singh, 1981). Oyster mushroom can be grown on most of the agricultural wastes of which sugarcane bagasse proved to be the best substrate for sporophore production (Khan & Khatoon 1982).
Pleurotus sajor-caju can be grown on wheat straw, paddy straw, stalks and leaves of sorghum, pearl, millet and maize for commercial cultivation. The cotton stalks and leaves induced high yield (2361 gm/10Kg substrate) followed by sorghum stalk and leaves (1463 gm/10 Kg substrate) of oyster mushroom (Patil et al., 1989). Four strains of oyster mushroom on cotton waste showed fastest spawn running in blue gray strain of P. ostreatus with highest yield in first and third flush while P. sajor-caju gave highest yield in second flush (Muhammad & Khan, 1993). The cultivation of P. sajor-caju on bagasse medium showed vigorous growth and highest yield of 174 Kg FW/100 Kg medium than wheat straw and wheat bran (Shi, 1994).
The objective of the present project work was to evaluate production and quality of the edible mushroom Pleurotus sajor-caju cultivated on fresh and washed rice straw, supplemented with a nutrient solution of arhar.
MATERIAL AND METHODS
Production of inoculum: the production of inoculum in test tubes was performed according to Bononi et al. (1995).
Production of spawn: wheat grain was cooked for 15 minutes, drained and cooled, and 6g calcium carbonate and 12 g gypsum per kg were added in relation to their mass (Gabrielli et al., 2002). A bottle was filled with ¾ parts and autoclaved twice at 15 plb. Then in a closed sterilized chamber mycelium of innoculum was transferred. It was autoclaved at 250C.
Production on washed substrate:
Rice straw were brought and dipped in a tank for wetting about 24 hours. It was sterilized by autoclaving. Straw was sterilized twice so that there would be no contamination. Now the sterilized straw was packed in a polythene bag and weighted. Spawn were sprayed layer by layer so that there would be equal germination in the bag.
Within 15 days the mycelium grows in size and polythene had cut carefully. Spraying water by hand every day so that there would be about 85% humidity. A cluster of mushroom start to grow and within 6-8 days ready for harvesting.
Mushroom were harvested by using scissors so that no extra mushroom mycelium would be teased.
RESULTS AND DISCUSSION
The spawn run on the substrate could be observed from the third day of incubation in the growing-room, with the formation of light pink halos around the spawn, indicating the beginning of degradation of the substrate by the fungus. The natural induction of primordia on the washed and pasteurized substrates occurred between 15-17 days of incubation, and the first flush or harvest occurred after 20 days of incubation. The mushrooms sprouted in clusters, and had the grayish-brown color that is characteristic for the species (Stamets, 1993). First harvest was on 21 Poush 2067
SN/Name Dry weight 1st harvest Average weight
Ujjwal KS Kushwaha 3kg 400g 390g
Laxman Aryal 3.5kg 450g
Krishna Acharya 3.5kg 300g
Udhav paneru 2.75kg 350g
Sandesh Dangi 3.5kg 450g
Different types of substrates have been used to grow Pleurotus sajor-caju in several papers, with ABE values from 32.10% to 79.18% (Chang et al., 1981; Bahukhandi & Munjal, 1989; Colauto & Eira, 1995; Sturion & Oetterer, 1995a; Dhanda et al., 1996)..
Contaminations may occur in most cultivations, because the mycelium becomes weaker after successive cultivations, or due to inappropriate management (Ferreira, 1998).
According to Balasubramanya & Kathe (1996), the microorganism species that competed with Pleurotus sp. after pasteurization with hot water (80°C for 2 hours) were the fungi Penicillium sp. and Trichoderma sp., probably due to the partial breakdown of cellulose and hemicellulose, making them available to competitors. Pasteurization at 90°C could make cellulose more available (Sturion & Oetterer, 1995a), due to the partial destruction of the lignin-cellulose bonds, favoring substrate contamination. Thus, contamination of the pasteurized substrate could have occurred because of the temperature and time used during pasteurization, since the literature is quite variable with reference to these characteristics (Bahukhandi & Munjal, 1989; Stamets, 1993; Balasubramanya & Kathe, 1996; and Sturion & Ranzani, 1997).
Hence bye this way we were able to perform mushroom (Pleurotus sajor caju) cultivation. Average weight of mushroom in 1st harvest was found to be 390 g.