Mushroom farming in Zimbabwe is a business idea with very low startup capital requirements. At the bare minimum, a mushroom growing project can be started an unused room in your house and given the availability of additional resources, it is also possible to scale. While the farming of mushrooms in Zimbabwe (or even their consumption) is not that popular, it happens to be a relatively uncrowded niche with few suppliers and given the right kind of marketing, producers can also find customers in their towns, neighbourhoods and local businesses.
A quick introduction to mushrooms
Mushrooms are edible fungi that grow on decaying organic matter usually referred to as the substrate. Unlike plants, mushrooms do not require sunlight with many varieties actually faring much better in its absence. This also allows them to be grown indoors. Mushrooms have high nutritional value being rich in protein, vitamins and carbohydrates but low in fat.
There are two main mushroom varieties grown in Zimbabwe namely the white button mushroom and to a lesser extent, the oyster mushroom.
If you don’t want to waste your time and money on a failed mushroom growing project, you should try to acquire as much information as possible on the subject beforehand. Mushroom production is very unique from any other kind of farming technique which you may already be familiar with. Read as much as possible on the topic or, even better, get in touch with someone who has already managed to successfully grow mushrooms in Zimbabwe. This last part is more important than you think; a lot of research has been conducted on the growing of mushrooms in moderate climates while considerably less has been done on their production in tropical ones like the one in Zimbabwe. This means that the vast majority of the literature that is out there is targeted at farmers located in a completely different climate from ours. Unfortunately, mushrooms are very sensitive to environmental conditions and you should only stick to trying to growing varieties which have already been successfully grown in Zimbabwe and also try to follow the same methodology that has already been successfully used in the country.
Mushrooms require very specific environmental conditions for them to grow and the easiest way in which this can be achieved is by growing them inside an enclosed space such as a room. A room will allow environmental factors such as temperature, airflow and humidity levels to be controlled while also preventing exposure to sunlight and contaminants since mushrooms don’t do well when they are contaminated by pests or even other types of fungi.
Since the temperatures inside the room used for growing have to be controlled, the type of roofing used on the structure matters since some materials such as corrugated steel may allow excessive heat both in and out of the room.
As mentioned before, the mushrooms need something to grow on. However, substrates are not only just a medium for growth, they also happen to be the growing mushrooms’ source of nutrients and energy. Unlike plants which have their energy needs satisfied by the sun, fungi like mushrooms have to get it all from their food, the substrate. The type of substrate required varies based on the mushroom variety but some of the most common are agricultural wastes such as maize cobs and sugar cane bagasse. Even more commonly used are wood chips, sawdust, wheat straw, bush grass, manure, ammonium nitrate and gypsum.
A large part of preparing the substrate involves ensuring that no pests or contaminants are present in it when production starts. While simple techniques can be used to achieve this in small-scale operations, larger ones may require more sophisticated equipment to pasteurise (i.e killing the parasites using heat) the substrates, the room and the equipment used.
The substrate, specifically its amount, also helps determine the mushroom yield. For instance, under average conditions, between 50 and 70kgs of oyster mushrooms can be produced from 100kgs of the substrate.
Mushrooms start as very small spawns. These spawns can be considered to be the mushroom equivalent of seeds. Unfortunately, the production of spawns is highly technical, even more so than that of the mushrooms themselves. It, therefore, makes more sense that those who wish to farm mushrooms just buy the ready to innoculate spawn of the mushroom variety that they wish to grow. The amount of spawn required is usually between 2% and 4% of the substrate weight.
Fresh mushrooms are about 90% water. This means that significant amounts of water are needed for their production. Water is needed to keep the substrate wet and to produce a humid atmosphere in the room being used for production.
Most mushroom varieties have a very narrow temperature range within which they can be successfully grown. This means that temperature control is very important during their production. Luckily in small-scale production temperature can more or less be controlled just by choosing the right building and insulation materials. Larger scale production may on the other hand require fans, heaters and other more sophisticated apparatus for controlling environmental conditions.
The production process
After everything is in place, the substrate is mixed with the spawn in suitable quantities. For instance, the damp substrate can be mixed with spawn and packed into plastic bags. These bags are hanged in the farming room. They also have to contain slits to allow the mushrooms to grow out of. After each production cycle, everything has to be cleaned and decontaminated before reuse.