Farming (Agriculture and Animal husbandry)

Introduction 

Though mushrooms are classified as vegetables, they are not plants as such, but belong to the fungi kingdom. However, they provide several important nutrients to human beings and this makes their cultivation beneficial. Mushrooms are divided into two categories, the poisonous and the edible mushrooms. This unit gives an insight on the identification of the edible mushrooms from the non-edible ones. It also gives practical experiences on how to grow the edible mushrooms. The process of growing mushrooms starts with the gathering and preparation of substrate materials where the mushrooms are grown, mushroom tube making and arranging the tubes in prepared nursery beds. Also addressed in this unit are the conditions suitable for mushrooms establishment and growth, up to the time they are ready for harvesting. The pictures below gives an over view of the unit.

2.1 Definition of mushroom 

Activity 2.1: Finding out the meaning of mushrooms 

Materials required 

• Dictionary 

• Textbooks

 • Internet

 Using the references provided, carry out the following activities:

 (i) Find out the meaning of mushroom from the dictionary, text books and internet. 

(ii) Discuss and record your findings. 

(iii) Present your findings to the class. 

(iv) Take the teacher’s summary notes. Mushroom is the fruiting body of a macro-fungus. A fungus is a non-photosynthetic organism that feeds on dead plant materials and organic matter.

2.2 Types of mushrooms 

Activity 2.2: Finding out the different types of mushrooms 

Materials required 

• Internet 

• School library 

• Pictures of mushrooms 

• Video tapes or CDs.

 Using the materials provided, carry out the following activities:

 (i) Find out the edible types of mushrooms and the non-edible mushrooms.

 (ii) Find out the types of mushrooms for commercial production. 

(iii) Discuss and record your observations. 

(iv) Present your findings to the class.

 (v) Take teacher’s summary notes.

There are two types of mushrooms: 

• Edible types. 

• Non-edible types or poisonous mushrooms

 (a) Edible types of mushrooms: These are mushrooms that are eaten by human beings without causing any harm. 

 There are five common types of edible mushrooms grown in East Africa.

 (i) Button mushrooms (Agaricus spp) – Has very short stalks almost nonvisible when growing. It is white in colour and the cap looks like a button.

 (ii) Oyster mushroom (Plerotus spp) – Completely white with oyster shell shape.

 (iii) Shiitake mushroom (Lentinula edodes) – Has a large brown cap which cracks when overgrown. 

(iv) Chinese mushroom (Ganoderma) – They are pink in colour with brown stalks.

 (v) Lions mane mushroom (Hericium erinaceus) – It is white in colour and the caps have cotton like appearance.

(b) Non-edible types of mushrooms These are poisonous though they resemble and taste like the edible mushrooms. They include:

 (i) Amanita phalloides – Golden brown in colour with staut stalk. 

(ii) Gyromitra infula – Brown in colour but appear red when cooked. They have a white stock. 

(iii) Amanita muscaria – This is red in colour with white cotton-like spots on the cap. It has a white staut stalk and is the most poisonous of all mushrooms in this category.

 (iv) Chlorophylum molybdites – It is white in colour with a white ring on the stalk.

2.3 Propagation of mushrooms 

Activity 2.3: Finding out the process of propagation of mushrooms

 Materials required

• Library books 

• Internet 

• Video

 Using the references provided, carry out the following activities:

 (i) Find out the stages involved in mushroom propagation. 

(ii) Discuss and record your findings. 

(iiii) Present the report to the class.

 (iv) Take teacher’s summary notes.

Mushroom propagation is the practice of growing mushrooms. It involves mushroom compost making, spawning or seeding the compost, casing and pinning.

Compost making: Involves gathering of materials such as bargasse, coffee husks, sawdust, rice husks and sterilising them by heating in steam. Other materials such as lime and molasses are added. 

Spawning: Involves sprinkling of mushroom spores on the sterilising culture which is then left to establish under controlled conditions of temperature and humidity. 

Casing and pinning mushrooms: Involves transferring the established mycelium into mushroom tubes, logs or a mushroom house containing substrate.

2.4 Production of mushroom tubes

 Activity 2.4: Mushroom tube making 

Materials required 

• Substrate materials such as straw, sawdust, maize cobs and banana fibres.

 • Equipment such as drums, polythene bags and sisal strings. 

• Supplements such as lime, animal concentrate, soya meal and molasses. 

• Fuel such as charcoal and firewood.

 Using the materials provided, carry out the following activities:

 (i) Prepare mushroom tubes by filling polythene bags with mixed substrates and supplements. 

(ii) Tie the mushroom tubes with strings and pack them into clean bags or large cooking pots. 

(iii) Sterilise the mushroom tubes by steaming for 3–4 hours in heated water drums. 

(iv) Leave the mushroom tubes to cool overnight. (v) Discuss and record your observations.

 (vi) Present your findings to the class. 

(vii) Take teacher’s summary notes.

A mushroom tube is a sack, polythene bag or crate containing growing materials which have been sterilised and used to grow mushrooms. The materials needed in the mushroom tube making include:

 (a) Substrate or compost – This constitutes of grass chaff, saw dust, straw, sugarcane bargasse, dry groundnut waste, banana fibres, dry banana leaves, straws, maize cobs and stalks.

These materials mainly provide carbohydrates.

 (b) Containers such as empty gunny bags, sisal sacks, crates, wooden racks and polythene bags.

 (c) Equipments – The following equipment are required:

• Drum which is clean

 • A big cooking pan or sufuria with lid 

• Plastic rings 

• Cotton wool 

• Preparation table or large leakproof paper.

 • Weighing scale

 • Water

 • Fuel for heating, for example, firewood or charcoal 

• Methylated spirit 

• Mushroom spawn or seeds

(d) Supplements – These are added to provide different types of nutrients needed for mushroom growth. They include; lime, molasses, animal concentrates and soya bean meal. 

The steps followed in making mushroom tube include: 

(i) Gathering of compost making materials. 

(ii) Mixing substrate with supplements: These materials are gathered, chopped into small pieces and washed clean using water to remove soil particles. They are then mixed with supplements. 

(iii) Drying: The compost material should not be very wet because it encourages growth of unwanted fungi and bacteria. Excess water is, therefore, removed by squeezing. 

(iv) Packing up or bagging: The semi-dried compost material is crushed and packed in polythene bags or gunny bags known as tubes. 

(v) Composite sterilisation: The competitive micro-organisms such as bacteria and unwanted spores of other fungi are killed through steaming for 3 hours or using chemicals such as isopropyl alcohol and hydrogen peroxide. After sterilisation the compost is left to cool overnight. 

(vi) Mycelium sowing: The preparation table is sterilised and the mushroom substrate spread on it. The mushroom spawn is spread evenly on the substrate and covered. The temperature and humidity is controlled at 20°C and 90 – 95% humidity. The substrate with white mycelium is transferred to mushroom tubes or the field.

2.5 Factors affecting mushroom tube making 

Activity 2.5: A field visit to observe factors affecting mushroom tube making and mushroom cultivation Materials required

• Questionnaire

 • Note books and pens

 Make a visit to a co-operative or a household producing mushrooms and carry out the following activities: (i) Observe mushroom tube making and growing of mushrooms. 

(ii) Find out the factors affecting mushroom tube making.

 (iii) Discuss and record your observations. 

(iv) Present your findings to the class.

 (v) Take the teacher’s summary notes.

 Mushroom tube making is affected by the following factors:

1. Availability of mushroom substrate material: such as sawdust, straw, sugarcane bargasse.

 2. Availability of transport: The materials for making compost are bulky, therefore, they should not be acquired from a distant source. They should be easily transported using wheelbarrow, lorries and tractor trailers. 

3. Cleanliness of the substrate material: Dirty substrate introduces unwanted bacteria and fungi, which interfere with growth process. 

4. Method of sterilisation: Once the mixed substrate materials have been packed, there are several methods of sterilisation. The cost of the equipment or chemical determines the method used which include use of pressure cookers, use of a drum or large cooking pot with water. Chemicals on the other hand are expensive and require a trained person to use. It is cheaper to heat in steam at 70°C , 80°C for 3 – 4 hours in a drum. 

5. Type of packing materials: The recommended packing material is use of clear

polythene bags measuring 25–30 cm wide against 45 cm length although this is subject to the availability and laws of the country.

2.6 Mushroom cultivation techniques 

Activity 2.6: Cultivating mushrooms in the nursery 

Materials required

• Mushroom tubes containing growing mycelium 

• Mushroom house with benches or hanging rods 

• Water 

• Thermometer 

• Hose pipes

 Using the materials provided, carry out the following activities: 

(i) Prepare a mushroom house by cleaning and watering the walls.

 (ii) Transfer the mushroom tubes in the house and hang them by the rods from the roof. 

(iii) Make small holes on the side of the mushroom tubes.

 (iv) Provide shade to prevent direct light.

 (v) Water the mushroom tube once a day by sprinkling or spray misting.

 (vi) Weed by removing unwanted or old mushrooms.

 (vii) Crop the mushrooms between 7 and 14 days or four days after the fruiting caps begin to appear.

 (viii) Discuss and record your findings.

 (ix) Present your findings to the class. 

(x) Take teacher’s summary notes.

Mushroom cultivation involves the transfer of spawned mushroom to growth material or the substrate into a specially prepared room where light, temperature and humidity are controlled. In this room, the young mushrooms are cared for until they are ready to be harvested, where they can be sold fresh or they can be dried, packed and sold. It involves the following:

1. Inoculation process

This process involves introducing mushroom spawn into the sterilised substrate. The spawn is evenly spread over the substrate at the rate of 7 kg per one tonne wet substrate. Different mushroom types have different spawning rate. The lighter the spore ratio to the substrate, the faster the colonisation of the sterile substrate. Study the photographs provided in the Table 2.1 and then identify the activities being carried out, materials required for each stage and the procedure.

2. Arranging mushroom tubes in the nursery bed 

After the process of inoculation, the polythene bags with sterile substrate are arranged in a nursery bed. This is a room specially prepared with benches where humidity, temperature and light are controlled. The bags are either packed on a bench or hang from the roof or an elevated point after the mycelium spread and seen as a white mass. The bags are opened or holes made on the plastic bags.

3. Shading

 Mushrooms which are grown in green houses or fields should be provided with a shade to prevent strong light.

4. Watering and weeding 

Watering is important to maintain the humidity of the substrate. The air humidity should be maintained at between 90% and 95%. This prevents production of mushrooms with a scaly skin. Watering is done by sprinkling or spray misting water once a day. It is also necessary to make holes measuring 1cm diameter on the polythene bag. This allows the small mushroom heads to force themselves out of the bag. Weeding is done by removing unwanted or old mushrooms.

5. Harvesting 

Mushroom will start to appear in 7–14 days. They should be picked when fully grown or when they stop growing. This happens 4 days after the fruiting caps begin to appear. Picking is done by twisting the mushroom stalk once to free them from the substrate medium. All old or aborted mushrooms should be removed from the substrate surface and discarded. After harvesting, the substrate should be kept moist to allow growth of another crop of mushrooms. Harvesting can be done 4–5 times depending on the species but the greatest harvest takes place between the first and second harvest.

2.7 Factors affecting mushroom cultivation 

Activity 2.7: Finding out the factors affecting mushroom cultivation 

Materials required

• Library books 

• Internet 

• Textbooks

 Using the references provided, carry out the following activities: 

(i) Find out the factors affecting mushroom cultivation.

 (ii) Discuss and record your findings.

 (iiii) Present your findings to the class. 

(iv) Take teacher’s summary notes.

The following factors are required to ensure a good crop of mushrooms: 

(i) Light: Mushrooms require light to grow but not direct sunlight. Regular strong reading light is sufficient. The mushroom cultivation house can also be left dark overnight. Shading can be provided to minimise light.

 (ii) Temperature: Mushrooms grow well in a temperature range of about 20°C – 25°C. It is recommended to put a thermometer to monitor the temperature of the mushroom cultivation house.

 (iii) Water and humidity: It is important to water the mushrooms to maintain the humidity at between 90 and 95% every once a day. Too little water makes the growth of mushrooms slower and leads to cracking of the fruiting caps. Too much water results in rotting of the substrate which encourages growth of unwanted bacteria and fungi. 

(iv) Amount of oxygen: Oxygen is required to stimulate growth. It is necessary to open the windows or liners to encourage free circulation of air. Lack of fresh air will prevent mushrooms from growing and produce long stringy mushrooms.

 (v) Mushroom diseases: Mushroom cultivation is subject to attack by both bacteria and fungal diseases. (a) Fungal diseases 

(i) Dry bubble: Caused by a fungus Verticillum fungicola. The symptoms include brown spots on the mushroom caps and is controlled by reducing the relative humidity and temperature to 14°C, disinfection of the substrate by steaming and disinfecting harvesting tools.

(ii) Wet bubble: Caused by a fungus Mycogone pemicosa. The symptoms include malformed cap and stalk. The disease mushrooms are covered with white mycelium on the cap. A foul smell is also produced. The control involves steaming of the substrate at 70–80°C for at least three hours.

 (iii) Other fungal diseases include Mildew and Aphanocladium disease.

 (b) Bacteria diseases which affect mushrooms include brown blotch, mummy disease and drippy gill.

 (i) Level of nutrients Good mushroom production depends on the amount of carbohydrates, proteins and calcium. The recommended amounts are 5–10% of substrate weight carbohydrates, 2–4% of protein and 2% calcium in form of lime water.

 (ii) Size of bag The recommended size of the bag should be 30 cm wide and 45–90 cm long for easy transportation and management.

Group Activity 

Observation, preparation and harvesting of mushrooms

Visit a co-operative or farmer growing mushrooms around the school and carry out the following activities: (i) Observe and record the types of substrates the farms use for growing mushrooms. 

(ii) Observe and record the substrate packing and sterilisation process and record the most applicable and cheap method to be carried out in the school. 

(iii) Observe the inoculation and capping process. During the process, ask how much spawn is applied per quantity of substrate. 

(iv) Arrange the mushroom tubes in the nursery bed. 

(v) Observe the mushroom cultivation management practices. 

(vi) Ask about the challenges facing mushroom production.

 (vii) Observe a demonstration of the mushroom harvesting process and participate in picking mature mushrooms.

 (viii) Observe the process of packing harvested mushroom in readiness for selling. 

(ix) While in school, discuss your observations in the farm and make a report. 

(x) Present your findings to the class. 

(xi) Take the teacher’s summary notes.

Unit Summary 

A mushroom is a fruiting body of macro-fungus whose parts or whole body are utilised. There are two types of mushrooms. 

• Edible mushroom 

• Non-edible mushroom. These are mostly poisonous.

Mushroom propagation is the agricultural practice of growing mushrooms using special facilities and mushrooms growing rooms. It involves mushroom tube making, inoculation, incubation, watering and weeding mushrooms and finally harvesting mushrooms. Mushroom propagation begins with substrate/compost making which is washed, sterilised and packed in bags either plastic bags or gunny bags in a process known as mushroom tube making.

A mushroom tube is a sack or bag made of polythene containing mushroom growing materials that have been sterilised. Mushroom growing materials include sawdust, grass chaff, dry groundnut waste, straw, maize cobs and chopped maize stalks. Mushroom growing containers include sisal sacks, polythene bags, empty gunny bags, crates and wooden racks.

Mushroom growing equipment includes a large metal drum or large cooking pot with a lid, plastic rings, weighing scale, water, fuel such as firewood and charcoal, methylated spirit and mushroom spawn seeds or mushroom spores. Mushroom supplements include animal concentrate, soya meal, rice bran or wheat bran, molasses and lime. The process of mushroom tube making involves:

• Gathering of substrates or compost manure. 

• Washing of substrate. 

• Mixing substrate with ingredients and supplements. 

• Drying. 

• Packing the substrate in tubes. 

• Compost or substrate sterilisation. 

• Mycelium sowing. 

• Observation of growing mycelium.

Substrate sterilisation involves boiling of the substrate in steam at 70 – 80°C for 3–4 hours or using a pressure cooker heating the substrate at 120°C for 15 minutes. Mycelium spores or spawn should be obtained from reputable mushroom growing. Apply 0.3–0.5 kg of spawn per 6–8ft3 of sterilised substrate or 0.3–0.5 kg of spawn per 12–15ft3 or 7 kg of spawn per tonne of wet substrate.

The factors affecting mushroom tube making include: 

(i) Availability of mushroom substrate materials. 

(ii) Availability of transport. 

(iii) Cleanliness of substrate. 

(iv) Method of sterilisation. 

(v) Type of packing material. 

(vi) Type and amount of mycelium spores and spawn used during inoculation. 

(vii) Temperature and humidity of the substrate. Mushroom cultivation involves the transfer of spawn mushroom to growing material then transferring the same to a specially prepared nursery bed with controlled light, temperature and humidity

Key Terms 

 1. Mycelium – These are fungal threads that spread over and in the substrate which later sprout to mushroom. 

 2. Spores – These are minute mushroom seeds that appear like powder. They are spread over a sterile culture substrate during inoculation. 

 3. Compost or substrate – This is a mixture of straw, sawdust, lime water, wheat bran and soya meal where the spores are inoculated after sterilisation. 

 4. Nursery bed – This is the space used to grow mushrooms where the temperature, humidity, light and oxygen concentration are controlled. They can also be referred to as shelves. 

 5. Mushroom – This is a fruity body of macro-fungus. 

 6. Mushroom tube is a sack – Bag or crate containing mushroom growing materials. 

 7. Bagging – This is the process of putting mushroom growing substrate in a bag or tray. 

 8. Compost sterilisation – This is the process of killing germs and other unwanted micro-organisms in a substrate using heat, steam or chemicals. 

 9 Spawning – This is the introduction of a pre-sown substrate mycelium known as a spawn into a substrate by sprinkling. 

10. Inoculation – Used similarly as spawning. 

11. Bargasse – The fibre remnants of sugar cane after it has been crushed to extract the juice. 

12. Gunny bags – Bags made of sisal fibres.

Revision Questions 

 1. What is a mushroom?

 2. Name two types of mushrooms. 

 3. (a) Name four edible mushroom types.

 (b) Name four non-edible mushroom types.

 4. Identify the mushroom type shown in the figure below:

5. Which of the following statements best describes mushroom propagation? 

 A. Transfer of mushroom tubes into specifically prepared rooms where environmental conditions are controlled. 

B. An organic substance originating from plants and used to grow mushroom. 

C. Allowing a mushroom spawn to colonise a substrate by providing the optimum condition for mushroom growth. 

D. Introduction of a spawn into a subtrate by sprinkling.

 6. Give examples of mushroom growing substrate or materials. 

 7. Describe the processes involved in making mushroom tubes.

 8. Outline the importance of compost/substrate sterilisation. 

 9. List factors affecting mushroom tube making. 

10. Carry out the activities involved in mushroom cultivation. 

11. Why is it important to spread the spawn or spores over the surface of the substrate while planting or inoculating the substrate? 

12. State the importance of watering the substrate during mushroom cultivation. 

13. Carry out the harvesting of mushrooms.

 14. Explain how the following factors affect mushroom cultivation:

 (a) Water and humidity. 

(b) Mushroom diseases. 

15. The following activities are carried out during mushroom production process:

 (i) Gathering and chopping substrate.

(ii) Watering of the mushroom tubes. 

(iii) Packing the bags containing substrate in the nursery bed. 

(iv) Sterilising substrate to kill harmful organisms. 

Which set of activities is correct for mushroom inoculation process?

 A. (i) and (iii) 

B. (i) and (iv) 

C. (ii) and (iii) 

D. (ii) and (iv)