The button mushroom, Agaricus bisporus is one of the most widely cultivated mushroom species. Mushroom growers inoculate compost beds with spawn, which is the vegetative mycelium and serves as the inoculum or seed for cultivating mushrooms. Various cereal grains, such as wheat, millet, barley, sorghum, brown rice, rye, and oat can be used in the spawn production of button mushroom. In this study rice seed bag spawn was compared with wheat grain bottle spawn in the spawn production. When the physical properties of two cereal grains were compared the 1000-kernel weight were 32.0g in wheat grain and 24.9g in rice seed. Number of kernels per milliliter were greater in rice seed compared with wheat grain with 24.5. Wheat grain showed 41.0% of total carbon level and 2.49% of total nitrogen level resulting 16.6 C/N ratio. Nitrogen content of rice seed was lower compared to that of wheat with 0.96 resulting 39.5 C/N. It was possible to produce 50kg of rice seed spawn in 22×49cm polypropylene filter bag with only 1~2 shakings compared to 0.45kg of wheat grain spawn in 1,000mL Ringer bottle with 4~5 shakings. Based on the results obtained, rice seed bag spawn would be appropriate substitute for wheat grain spawn in button mushroom.

To minimize cultivation costs, prevent insect-pest infestation, and improve the production efficiency of thermophilic mushrooms, plant substrates obtainedfrom local areas in Cambodia were used for production of both spawn and mushrooms. In this experiment, different sawdusts different organic wastes and grain ingredients and analyzed for improvement of spawnproduction efficiency. Four thermophilic mushroom species, Pleurotus sajor-caju (oyster mushroom, Sambok), Ganoderma lucidum (deer horn shaped), Auricularia auricula (ear mushroom), and Lentinula edodes (shiitake), were used to identify efficient new substrates for spawn and mushroom production. Although the mycelia in the rubber tree sawdust medium showed a slightly slower growth rate (10.9 cm/15 days) than mycelia grown in grains (11.2 cm/15 days in rice seeds), rubber tree sawdust appeared to be an adequate replacement for grain spawn substrates. Th findings indicate that rubber tree sawdust, sugarcane bagasse, and acaciatree sawdust supplemented with rice bran and calcium carbonate could be new alternative the substrates for . Although sugarcane bagasse and rubber tree sawdust showed similarly high biological efficiencies (BE) of 60% and 60.8%, respectively, acacia tree sawdust exhibited relatively a low biological efficiency of 22.4%. However, it is expected that acacia sawdust has potential for the mushroom cultivation when supplemented with currently used sawdust substrates in Cambodia, because of its relatively low price. The price of the sawdust (20 kg sawdust= 6500 Riel or 1.6 USD) currently used was 6.5 times higher than the price of acacia sawdust (201000 Riel or 0.25 )USD). Therefore, utilization for acacia sawdust for mushroom cultivation could become feasible as it would reduce by producing costs of mushrooms in rural areas of Cambodia.

Spawn is the vegetative growth of the mycelium and serves as the inoculum or seed for cultivating mushrooms. Various cereal grains, such as wheat, millet, barley, sorghum, brown rice, rye, and oat were assessed to compare their characteristics and suitability for spawn production of button mushroom (Agaricus bisporus). The mycelial growth rates, density, and the number of completely colonized grains were measured from the twentieth day of inoculation. Wheat grains showed fastest mycelial growth with 8.4 cm followed by rye, oat, barley with 8.2, 7.5 and 7.3 cm, respectively. In the mycelial density, foxtail millet, barley, and sorghum were best compared with that of wheat grains. Especially, the number of grains which were completely colonized by mycelia were greatest in foxtail millet with 5,123 grains followed by proso millet, and wheat with 3,052 and 914, respectively. Based on the results obtained, barley, foxtail millet, and sorghum grains would be appropriate substituting for wheat grain in spawn production of button mushroom.

느타리버섯 재배시 현재 톱밥병종균을 대체할 수 있는 저비용 우량봉지제조기술을 개발하기위해 시험을 수행한 결과는 다음과 같다. 1. 재료의 산도 (pH)는 포플러톱밥이 pH 6.7, 미강은 pH 6.4에 비하여 비트펄프는 pH 4.9로 다른 배지재료에 비하여 산성을 나타내었다. T-C는 포플러톱밥 57.5%, 면실피 54.5%, 미강 52.4%로 나타났고, T-N는 포플러톱밥이 0.1%로 면실피 1.77%, 미강 0.94%로 나타났다. 2. 균사생장정도는 신농73호 2.5kg 규격 종균의 필터가 구비된 종균의 경우 15.7㎝, 마개형 10.5㎝, 필터가 없는 종균은 7.5㎝로 필터구비종균이 생장이 우수하였고, 균사밀도의 경우에도 필터형이 밀도가 높았다. CO2 농도는 신농73호 2.5kg 규격 종균의 필터가 구비된 종균의 경우 1,400ppm, 마개형 2,200ppm, 필터가 없는 종균은 3,200ppm 로 필터구비종균이 농도가 낮음을 알 수 있다. 3. 배양소요일수를 측정한 결과, 신농 73호에서 2.5㎏ 필터종균의 경우 18일, 마개필터 18일, 필터가 없는 처리는 19일로 큰 차이는 없었다. 생산량의 경우 신농73호에서 2.5㎏ 필터종균의 경우 118g, 마개필터 112g, 필터가 없는 처리는 100g으로 필터처리 종균이 생산력 측면에서 우수하였다.

The word spawn is derived from an old French verb, espandre , meaning to spread out or expand. Spawn is also defined as “the mycelium of fungi, especially of mushrooms grown to be eaten, used for propagation.” The effects of bag spawn to sawdust substrate on the growth of Pleurotus ostreatus were conducted. The duration of mycelial growth and days of pinhead formation of bag spawn(2.5kg) were 18~19 days and 7~8 days, whereas bottle spawn (1,000㎖) was 18 days and 6 days, respectively. The yield of mushroom fruitbody was that bag spawn is 100~118g, bottle spawn was 95~115g. In economical analysis, bag spawn is increased to 50%, compared to bottle spawn in relative income.