I am going to be posting my mushroom growing manuals slowly until I cover all the mushroom types that I train. I hope you will learn a lot through these serial posts, feel free to ask questions as I do this. The first post is on mushroom growing houses.
This manual is mainly aimed at basics at growing oyster mushrooms. For detailed scientific background and information on mushrooms refer to other detailed books.
Building requirements for a mushroom farm
In the early days mushrooms were grown in caves, nowadays mushroom houses are constructed. It is important that appropriate environment is provided for mushroom growing. As fungi are easily affected by the growing conditions, it can be concluded that success or failure of mushroom growing depends on the control of growing conditions.
Environmental factors affecting mushroom cultivation include humidity, temperature, light and ventilation. There are no standard design models for mushroom farms in Zimbabwe. Plastic sheds, thatched rooms and garages turns mushroom houses, but some people have heavily invested and built proper structures. Those venturing into the industry are warned to look at the costs of building materials.
The use of machinery to control temperature and humidity is not common in Zimbabwe; most oyster mushroom growers improvise and successfully maintain the conditions. Some fail to start mushroom growing projects because they feel they have to construct state of the art growing rooms, Simple growing houses can be constructed using cheap material or converting other structures into mushroom growing houses.
An ideal mushroom growing house does not necessarily need to be a high-tech, high-cost structure with all automatic controls. Some growers ruin their crops even in these state-of- the-art growing houses and other growers reap a rich harvest in humble sheds. The most important consideration is keeping an eye on preventing possible pests and pathogens and understanding the relationship between temperature, humidity and air exchanges. If the walls and the roof should be well insulated, the outside conditions should not have a big impact on the inside conditions. Insulation has a bearing on temperature control, therefore failure to insulate the house may lead to difficulties in controlling the temperature.
When designing and constructing a mushroom house care should be taken to leave holes for water pipes, electricity and air ducts, the level of operation and location of the business also affects some of the requirements for instance in rural areas. Oyster mushrooms can be grown without electricity, but electricity may be required for artificial ventilation and humidification of the room especially for big commercial farms.
The most common growing rooms are covered by grass and/or black sheeting. The cheapest floor is covered with the sand on the black plastic which is put on the floor. It is very good at keeping humidity at high levels when watered. Doors should close adequately to prevent insects from entering the growing room. Nets should be put on all windows to prevent insect entering as they are attracted by the smell of mycelium which is also very attractive to flies. For those who intend hanging their mushroom bags, the roof should be strong enough and the hanging frames so that they don’t collapse when bags are hanged. The mushroom house is very crucial to successful mushroom growing.