Paddy straw mushroom (Volvariella spp.)

Paddy straw mushroom (Volvariella spp.)

Paddy straw mushroom is one of the best loved mushrooms in South-Asian countries. It is consumed fresh or canned/dry and used extensively in Asian cuisines. It is having good combinations of all attributes like flavour, aroma, delicacy, high content of protein and vitamins and minerals, because of which, the acceptability of this mushroom is no way less than much popular white button mushroom. It is an edible mushroom of the topics and subtropics, and began to be cultivated in China as early as 1822. Around 1932-, the straw mushroom was introduced into the Philippines, Malaysia, and other south-east Asian countries by overseas Chinese. Since then, its cultivation has been conducted in various countries outside of the region. The fruiting body formation starts with tiny clusters of white hyphal aggregates called Primordia and it is followed by several morphological stages in the fruiting body development process. The successive stages are called as "button", "eggs", "elongation", "mature" stages respectively. Differentiation can be seen first at the 'button' stage. At maturity the buttons enlarge and umbrella like fruit bodies emerge after the rupture of the Volva. It can be plucked immature or at later stage. It tastes better when it is plucked just after rupture of volva.

Cultivation Technology

After harvesting of Rice plant the fresh straw is the most suitable for Mushroom cultivation. To begin with, the straw is tied into bundles of 1.2 m long x 25 cm diameter (tie end) size followed by Deeping of bundles in water in a cemented tank for 24 to 48 hours. This contains 1% CaCO₃ (Limestone) for killing of pests and insects. The bundles are taken out and put on a clean surface for few hours for draining out the excess water. The mushroom beds are prepared on a raised bamboo platform inside a thatched hut. Four pre-wetted bundles are placed side by side on this platform, facing all the loose ends on one side. Then another four bundles are placed with their tied ends on the opposite side. The loose ends of all the 8 bundles meet and overlap each other in the middle. Spawn is applied on this first layer about 15 cm away from the outer edge. On top of the spawned first layer, a little quantity of Gram dhal powder (about 200g per bed) is applied along with the spawn. On top of the spawned first layer of eight bundles again a second layer of 8 bundles is placed in a similar fashion and spawned. A third layer is again laid on top of the second layer and followed by 4^th layer of bundles and spawning. All these 32 bundles make a single bed which is now pressed to remove the entrapped air and make it compact for effective spawn run. In order to avoid rapid water loss, the beds are covered with polythene sheets or gunny sheets.

Spawning Spawn run

The individual beds are watered daily without opening them with a sprayer once or twice, depending upon the climatic conditions. The total dry weight of straw/bed is 25 to 32 kg. A minimum of 18 to 22 litre/ water bed is sprayed to maintain the moisture level of 65 to 70%. It takes 10 to 15 days for complete mycelial growth under optimum conditions of 30 to 35C temperature with 85 to 90% RH.

Mushroom Production

The spawn run beds are exposed to fresh air and the mushrooms start appearing within a few days. These are picked at button stage early in the morning. The fruiting bodies are carefully separated from the adhering straw. Mushroom production continues for a period of 2-3 weeks. Each bed of 30kg dry straw can produce 4 to 5 kg of fresh mushrooms.

When the mushroom production stops, the straw can be composted to form manure. This mushroom is very good in taste and valued for its excellent aroma.

Opportunity in Assam

Assam having annual rainfall and moderate climate could be a great place to grow Paddy Straw Mushroom. It could be one of the new food delicacies and farmers can grow as a new crop as Assam accounts for high Rice cultivation which will provide ample Straws for making of beds. This will provide good source of income for the poor farmers.

Jo’s Green Farm cultivates the paddy straw mushroom and had good result. We provide training to Entrepreneurs and farmers for learning of the techniques. 
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