Here’s what you need to know…
Whilst most of the world’s mushroom supply comes from commercial mushroom farms, growing mushrooms is not as simple as many people believe. In fact, mushroom growing is one of the most technologically advanced and sophisticated agricultural industries in the world.
Commercial mushroom production costs are high and require extensive capital investment. Whether you grow on small scale as a hobby; or on a larger scale, modern mushroom production is highly mechanised, requiring detailed knowledge and a high level of management skill and commitment for success. This commitment is required from the start all the way through to cropping and marketing.
In South Africa the white button and brown mushrooms are mainly grown, both of these belonging to the genus Agaricus. Furthermore it is mainly a fresh market with only a small percentage of SA’s mushroom production being processed into canned product, sauces and other value added products. It seems that the South African consumer has clearly made the choice to eat fresh mushrooms rather than processed mushrooms.
Less than 5% of the mushroom market is taken up by so called exotic mushrooms, including Pleurotus spp (Oyster mushrooms) and Lentinula spp (Shiitake). Although these mushrooms seem on paper to be less complicated to grow, one should not be deceived in thinking that it is an easier option. Even though oysters grow on un-composted cellulose material (no casing material is needed), and Shiitake on woody substrates containing lignin compounds, they still require the sophisticated technology to manufacture substrate and then climate controlled growing rooms.
Basic Procedures for Agaricus Mushroom Growing
Here are some important points to keep in mind.
Where are you based, city town, country?
Have you grown white and brown mushrooms before?
Most importantly have you made compost before for white and brown mushroom growing?
We can provide spawn compost, it comes in a reefer container being frozen. You need to defrost and use all at once, or have a freezer to store and use as you need.
NB We cater for white and brown mushrooms only, not exotic mushrooms!
This is a very technical business.
We would suggest you contact Mel Meyer +27-72-964-1817 who is a South African consultant in the mushroom growing industry and charges for his time. NB Mel consults only outside of South Africa, in other countries in Africa.
Rule 1: The most important rule in mushroom growing industry is compost, if you cannot make mushroom compost you fail. It is a very specific compost.
Rule 2: Hygiene.
Rule 3: Hygiene.
Rule 4: Hygiene.
Rule 5: Good quality peat.
To supply mushrooms you need to produce mushrooms at least every second day so that you can supply your clients. To do this you need more than one room as each room gives you a flush which is a harvest. This means you need 12-17 weeks stock of straw, chicken manure, Harte peat, spawn so that you can on an ongoing basis produce mushrooms and rotate the rooms.
1) Produce compost – takes 9 weeks or longer.
2) Move compost into the rooms and apply spawn. Allow spawn run.
3) Mushrooms pin and grow through the peat.
4) Harvest mushrooms on a rotational process.
5) Start from point one again so that you have continuous production.
Compost
Mushrooms belong to the fungi kingdom, which are heterotrophic organisms which lack chlorophyll and consequently produce their own food from an organic material. In the commercial production of Agaricus bisporus this food-and energy source is provided by a highly complex substrate or compost. Selective compost for mushrooms is found at the end of a complex, controlled biological process involving micro-organisms.
When well prepared, it is a living ecosystem that is suitable for the growth of mushrooms. To consistently prepare a high yielding compost is probably the most difficult part of the growing operation.
In the South African industry most growers produce their own compost unlike in Europe for instance where mushroom companies specialise in making compost for resale or growing the mushrooms from compost purchased from a composter.
Unfortunately in SA there is no compost readily available to purchase so mushroom farmers will have to make their own compost first.
Ingredients:
The basic ingredients for preparing a synthetic compost are:
Water
This is essential for the composting process and eventually for growth of the mushroom; on average 70-90% of all the mushroom’s water requirements is extracted from the compost.
Straw (mostly wheat)
Supplies the carbohydrates and provide the correct structure to allow aerobic conditions.
Broiler chicken litter
Acts as a nitrogen source and supplies microbes needed for the composting process to take place.
Gypsum
Added to improve the structure, buffers the pH and aids the release of ammonia.
The quantities used depends on the chemical analysis of the ingredients in particular the nitrogen content of the chicken litter.
Chicken Manure
A typical formula is: 1 000 kg straw (moisture content 15%)
800 kg broiler chicken litter (moisture content 40%, nitrogen 4%)
85 kg gypsum
The process of changing these ingredients into a suitable medium for mushroom production takes place in distinct phases.
Growing Mushrooms
It is very difficult to estimate the total cost of setting up a mushroom-growing facility. Many factors need to be considered, such as cost and availability of raw materials, the market size and proximity, the composting process (the extent of mechanisation, composting in ricks or bulk tunnels, aerated floors, blending lines etc.), the growing system (bags, trays or shelves), labour cost, size of the facility etc. A rule of thumb that the larger commercial mushroom farmers work by is ±R3.5 to R4million per ton of mushrooms that you want to grow per week. This investment can be broken down as: 50% for the composting and Phase II sections and 50% for the growing rooms. This excludes the costs for a pack-house, distribution fleets and staff buildings such as change rooms and toilets. This also excludes the requirement that you need straw for a year to make compost and a reliable chicken manure supplier.
Mushroom growing is a scientific operation which requires meticulous record keeping to achieve consistent results. Records and data sheets should be kept on each compost, from the time of pre-wetting until it is finally removed from the growing room as spent compost at the end of the crop. Such data should include the composition of the compost, analysis of the raw materials and the compost at various stages, growing
parameters, performance of each batch of compost in terms of quality of mushrooms, size and yield.
For those interested in mushroom farming, it is important to do your homework before investing in land or a production facility.
Please read the publications below.
Making of Mushroom Compost
How You Can Prevent Overlay
Procedures for Mushroom Growing
Disease/s Control
Bubble & Cobweb Control
These diseases are still a major problem for some growers who despite their best efforts are failing to control them. As a reminder the following are key points in control:
- Mostly these diseases are continually being recycled between crops in a unit. Measures to prevent this are thus vital.
- Both diseases are spread mainly by microscopic invisible spores. These carry in the air, on persons on flies and on equipment.
- Good fly control is essential for disease control.
- Emptying out a tunnel with disease is the time of greatest risk and best procedures must be followed.
Steaming is effective in bad cases.
Verticillium (Dry Bubble)
Both wet and dry bubble continues to cause problems for growers. Verticillium (dry bubble) is particularly troublesome. On a recent visit to Ireland a Dutch mushroom consultant, Henk van Gerwen, gave a talk to two of our Discussion Groups about this problem as he saw it.
Source:
Bubble is soil borne and therefore there is a potential source on every unit from soil contamination.
A few high-risk areas are:
- Wheels of casing lorries backing across lanes or stoned areas onto the concrete apron to tip casing.
- Soiled water running down/across aprons with tipped casing during or after heavy rain.
- Older diseased tunnels possibly exhausting spores.
Verticillium on casing will only begin to grow at pinning in a reaction to changes in casing sugar levels. Each point of infection produces spores in 24 hours. One point of infection can produce 125 million spores.
Spread
Spores are released in clusters and carried largely by people/pickers, flies and dust. They are very sticky and easily spread.
Watering onto a diseased crop is probably the best way to spread spores within the crop. If you spread spores at watering you will see new infection in the proximity of the original source in 4 to 7 days (in the 6/7 adjacent bags).
Experiments in Holland showed that at very high disease levels, Sporgon was ineffective in controlling spread but as levels reduced it became useful again.
Prevention
- Clean picking equipment daily.
Train pickers to identify initial infection. - Inform pickers and other staff of their role in spreading disease.
- Clean clothes/aprons for staff daily.
- Clean scales, knives.
- Take precautions if the same pickers work in old and new tunnels
- The day of disease outbreak can help you work back to most likely infection time (4-7 days earlier).
- Seal tunnels completely
- Eliminate fly problems. Flies are the perfect way to spread sticky spores.
- Areas where pickers and other staff congregate such as canteens would be high risk for cross infection (i.e) casing personnel, people emptying tunnels and pickers.
Treatment
Cookout is the best way of disinfecting.
Surface drench with a suitable disinfectant the day before emptying taking care to drench floors as well.
For spot treatment, cover disease with tissue and cover generously with salt.
Removing disease from casing should only be done by someone who understands exactly what they’re doing. Removing diseased spots carelessly is the perfect way to worsen the problem.
In Holland air intake and exhaust air is filtered.
