The Sunday Mail
Garden Affair
An average yield ranges from 15 kilogrammes to 30 kilogrammes per square metre and with just 200 grammes selling at US$1, the returns are good. With experience, your yield will improve by simply turning your garage, cottage or constructing a grass shelter which is a popular method in the rural areas.
During the rainy season, highways are lined with vendors selling various wild species of mushrooms. However, due to fears of poisoning from wild varieties, growing known species is a better alternative.
Mushrooms are one of the most nutritious foods. They are rich in protein, vitamins (B1, B2, and B3) and various minerals. They also have low sugar and salt. Besides these health benefits, mushrooms are said to also have a number of medicinal properties (healthy skin and reducing the risk of coronary heart disease).
There are two species of mushroom which are popular in Zimbabwe. These are Oyster (Pleurotus spp.) and White Button (Agaricus spp.). Let us look at the cultivation of Oyster mushrooms, which can easily be grown at any location by following a simple method.
It must be mentioned that the cultivation of mushrooms is both a science and an art. Hygiene, temperature and humidity control are the most important pillars of cultivating mushrooms.
It is always an added advantage to purchase a thermometer and a hygrometer (which measures humidity) if one is to do serious production. It is, however, not always a prerequisite in a garden or rural setting.
After choosing a good structure, which can be ventilated when necessary and also kept dark for incubation, one can look for the substrate that can be straw or grass, saw dust from carpentry workshops, maize stalks and leaves which are abundant now and wheat straw if one is near a wheat farm.
A slanted hard cement floor would be ideal to allow excess water to drain away.
Begin by chopping the material collected into smaller pieces of between seven and 10 centimetres. Soak the material in water, preferably in a drum overnight. To sterilise the material, boil it in a drum for two to four hours at 60 to 70 degrees Celsius.
A number of organisations specialise in producing spawn which is basically the seedling for mushroom cultivation. When one has sourced spawn and after cooling the straw, one can then begin to mix these by packing them into bags.
Empty potato, orange and fertiliser sacks or plastic bags can be used. Holes must be punched into the plastic bags, six centimetres apart, around the bag. Mix the spawn with the substrate (straw) at a rate of 500g of spawn with 10kg of material.
The handling of spawn at a suitable temperature is important during transportation. Place a layer of material followed by additional spawn.
These must be compressed thoroughly.
The bags are then hanged in the dark incubation room and arranged properly not too close to each other to allow movement of air and humidity. The bags are kept at a temperature of 20 to 25 degrees Celsius for 15 to 25 days at a relative humidity of 90 to 95 percent.
After three weeks, colonisation will have taken place and the temperature must be lowered to below 15 degrees Celsius.
Light can now be allowed in the room and the humidity must also be high at 90 percent, which can be achieved by spraying water five to six times during the day. Two to three buckets of water twice a day will suffice rather than 10 buckets.
However, do not spray the water onto the pinheads as this is harmful to them. A mist spray is recommended.
Once fruiting begins, mushrooms can be picked up within two to three days. Harvesting periods can be extended for months by maintaining the relative humidity.
Harvest by cutting using a sharp knife so as not to disturb the young fruits. By this time, your market must be ready to receive your product. Selling can begin whilst planning for the new crop can also commence.
