People all over the world have foraged and harvested wild mushrooms for food over millennia. A mushroom (or toadstool) is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. Mushroomcan also be described as a variety of gilled fungi, with or without stems.
Mushrooms, a member of the fungus family; rich in protein, vitamin B, and minerals, are edible crop with a large global market. There are different species or varieties of edible mushroom found in nature examples of which are – Button Mushroom, Portobello Mushroom, Oyster Mushroom, Paddy Straw Mushroom etc.
Mushroom farm business specializes in growing mushrooms. It is the cultivation and commercial sale of edible mushrooms for food and medicinal purposes; either on decaying organic matter like tree trunks or on soils through the following farming steps: Compost preparation, Spawning, Casing, Pinning and cropping, Harvesting Post Harvesting; care & management.
Mushroom farming can bring about good profit in just a matter of weeks with low start-up capital to initiate and start the business. These mushrooms depending on the type grown are used by customers for either medicinal or culinary purposes or may also be sold wholesale to clients or at retail prices. Mushroom cultivation is compatible with other farming and horticultural activities. It can be regarded as a very efficient system in recycling with no waste from production to consumption.
How to start your own mushroom business
Access to sufficient, suitable and locally-sourced substrate and spores are key determinants as to whether mushroom cultivation is likely to be successful and sustainable or not.
Key steps in mushroom production
The basic concept in cultivation is to start with some mushroom spores, which grow into mycelium and expand into a mass sufficient in volume and stored up energy to support the final phase of the mushroom reproductive cycle, which is the formation of fruiting bodies or mushrooms.
The key generic steps in mushroom production – a cycle that takes between one to three months from start to finish depending on species – are:
- Identifying and cleaning a dedicated room or building in which temperature, moisture and sanitary conditions can be controlled to grow mushrooms in;
- Choosing a growing medium and storing the raw ingredients in a clean place under cover and protected from rain;
- Pasteurizing or sterilizing the medium and bags in which, or tables on which, mushrooms will be grown (to exclude other fungi that would compete for the same space – once the selected fungi has colonized the substrate it can fight off the competition);
- Seeding the beds with spawn (spores from mature mushrooms grown on sterile media);
- Maintaining optimal temperature, moisture, hygiene and other conditions for mycelium growth and fruiting, which is the most challenging step; adding water to the substrate to raise the moisture content since it helps ensure efficient sterilization;
- Harvesting and eating, or processing, packaging and selling the mushrooms;
- Cleaning the facility and beginning again.
Spawn and inoculation
Mushroom spawn is purchased from specialist mushroom spawn producers, and there are several types or strains of spawn for each type of mushroom. It is not generally advisable for mushroom growers to make their own spawn because of the care needed to maintain the quality of spawn in the production process.
Spawn is produced by inoculating a pasteurized medium, usually grain, with the sterile culture (grown from spores) of a particular mushroom species.
The cheapest cultivation system using composted substrate is one where mushrooms are grown in plastic bags (which can be sterilized and re-used with new substrate) containing substrate or compost, in a simple building to provide controlled growing conditions. Bottles can also be used, and in other indoor low-cost systems wooden trays of different sizes can be arranged in stacks to provide a useful cultivating space. Spawn is added to the sterilized/ pasteurized substrate under hygienic conditions, in an enclosed space, and mixed thoroughly to ensure that the mushroom mycelium grows evenly throughout the substrate.
Farmers with limited resources can overcome the need to purchase spawn each time a new crop is put down by removing a portion of the substrate colonized by the mushroom spawn from the new crop and using it for spawning the following crop. However, care must be taken to remove only healthy, uninfected substrate colonized fully by the mushroom spawn.
suitable growing conditions
The inoculated substrate is put into bags, trays, etc. and transferred to an enclosed and darkened room or building to incubate for a period of up to 12 weeks, depending on the variety of mushroom. If space is limited, plastic bags can be suspended in darkened rooms.
Humidity levels are important for the mycelium to colonize over the next two weeks, so water needs to be available, and the temperature controlled accordingly to the variety of mushroom. The crop should be protected from sunlight and strong winds at all times, which can cause the mushrooms to dry out. Humidity can be maintained in the growing room by hanging wet rags at several points around the walls, or watering the floor. Temperature can be regulated by a fire, (electric if available) and cooling could be assisted by using a table fan blowing over a container of water, and air circulating between the sacks should help assist with temperature regulation.
It is essential to maintain hygienic conditions over the general cropping area, in order to protect the crop from contamination.
Harvesting cultivated mushrooms
The transition from fully-grown mycelium to produce mushroom fruiting bodies normally requires a change in the environmental conditions, such as temperature decrease and ventilation and humidity increase. Mushrooms fruit in breaks or flushes, and the type and size of mushrooms harvested depend on the type of mushrooms grown and market demand.
Mushrooms should be harvested according to market demand; for example, there may be a price premium for small button mushrooms. Generally, mushrooms are harvested by hand using sterilized knives to cut the ones that are ready. Pickers should be trained to recognize the appropriate stage for harvesting and be consistent in when the mushrooms are cropped.
Handling such a perishable crop should be kept to a minimum to reduce the risk of damage.
Pest and disease management
The basic principle in protecting the mushroom crop from pests and diseases is prevention, largely achieved through good hygiene. As mushrooms are grown mostly in an enclosed environment, the risk of pests and diseases spreading rapidly within the crop is high, so it is important to monitor the crop on a daily basis for incidence of pests and diseases, to prevent losing at least some of the crop. It is also important to sterilize the growing room and the preparation areas on a regular basis.
If and when pests or diseases are detected, control measures should be applied immediately. This may involve removing infected mushrooms by carefully picking them off without spreading the disease, then applying a pesticide. The type of pesticide required should be carefully chosen from a list of registered chemicals and used strictly in accordance with the directions given on the label.
Although there has been a great amount of research into mushrooms and their cultivation in temperate climates, there has unfortunately been comparatively little on varieties suitable for tropical climates. Many commercial mushrooms only fruit at around 20 °C and are therefore not suitable for tropical regions. Suitable tropical strains are harder to obtain, but some commercial strains can be ordered which fruit at higher temperatures and local laboratories which manufacture spore will be best placed to advise on appropriate varieties and in providing advice on best planting practices.
|Factors influencing the selection of mushroom species|
|Availability of waste materials to use as a growth medium. Not all mushrooms can be grown in the same substrate.|
|Environmental conditions. Different species have different requirements for temperature and other environmental variables.|
|Available expertise. Some mushrooms are more difficult to grow than others and, if there is little available expertise locally, farmers should start with easy species like oyster (Pleurotus species) which grow on many substrates and are easy for beginners; shiitake (Lentinus edodes) and maitake (Grifola frondosa) are other possibilities.|
|Available resources. It is necessary to identify what necessary equipment is needed and/or already available.|
|Market demand. If producers wish to trade.|
Assets required for mushroom cultivation
Mushroom cultivation can play an important role in helping rural and peri-urban people strengthen their livelihoods and become less vulnerable to hunger and poverty. Their cultivation requires a wide range of activities suitable for people with various needs, diverse interests and specific capabilities. Key assets or resources associated with mushroom cultivation are described below.
Scale of production
Growing systems should be selected that are best suited to local conditions and based on the assets available. Many species of mushrooms can be successfully cultivated on a small-scale, by farmers and other growers who have limited access to resources and vulnerable to risk. It is quite possible for growers to gradually shift from a low-cost system to a higher cost production process, with greater output, when they have gained sufficient skills and income.
Large-scale commercial methods of mushroom cultivation require significant financial investment to purchase steam sterilizers, and technical equipment for sterilization such as autoclaves, and often have laboratory facilities to produce spores.
Land and climate play a minimal role in mushroom cultivation and this feature makes the enterprise particularly suitable for farmers with limited land, as well as the landless. Unlike wild harvested fungi, grown mushrooms are not subject to any ecological uncertainties including habitat health, nor years of unpredictable production as a result of late or reduced rains.
Both rural farmers and peri-urban cultivators should be able to obtain agricultural by-products easily and cheaply to use as substrate; or, for certain mushroom species, logs or sawdust to inoculate with spores. Mushroom spores can be collected from mature fruiting bodies, but are commonly purchased from local production facilities or laboratories.
Harvested mushrooms need to be carefully handled and should be kept in a container that allows for air circulation, such as a basket, and care needs to be taken to prevent bruising. The baskets containing mushrooms should be covered to keep flies out and protected from sunlight, high temperatures and draughts. High quality mushrooms that are healthy and clean fetch the best market price. Harvested mushrooms should be taken to market without delay in order to maintain their freshness and quality, or stored in a refrigerated environment or processed.
Getting fresh specimens to market is considerably difficult, both for wild fungi and cultivated mushrooms. The physical appearance of fruiting bodies is obviously important and customer preferences must be observed. Some species become discolored if the gills or cap are damaged and they must be handled with care. Depending on the soil where the fungi grow, some preliminary cleaning of gills and gaps may be needed to remove particles. Picking fruiting bodies at the correct stage of development is important. As they mature, some species become woody and much less desirable, while others rot away.
Two hundred thousand should be enough to start a small-scale mushroom farm.