Mushroom Signals - English edition by Roodbont Publishers

Mushroom growing is not an exact science. The true art is learning to see, interpret and correctly respond to signals. And that art can be mastered.

Mushroom Signals aims to teach composters and growers how to optimise their processes by recognising signals they come across in practical situations. Not by jumping to conclusions immediately, but instead by always asking yourself three questions: what do I see, what has happened and what should I do? For instance: what do you see? The day after watering you notice the floor in the growing room is still wet and the casing soil surface is still shiny. What has happened? Not enough moisture is being extracted. This will prevent the development of the pinheads in the second flush, and bacterial blotch can occur. What should you do? Lower the RH and CO2 concentration. This is one of the many signals in mushroom growing that you can interpret to optimise the yield and quality of your mushrooms in an easy way. Every hour, a mushroom grows four percent! Instructing pickers to harvest the same bed several times a day quickly results in a production increase of at least ten percent. Coaching your team is equally as important as taking good care of your mushrooms. The conditions in which mushrooms are grown vary widely all over the world. But the signals given by compost and mushrooms are identical everywhere. If you know what to look for, you can pick up the signals everywhere and any time. Mushroom Signals will show you how.

ISBN 978-90-8740-136-8

9 789087 401368 www.mushroomoffice.com

www.roodbont.com

Mark den Ouden

The process of successful mushroom growing starts with assessing the raw materials used to make compost. This is the foundation of an optimal composting process. The challenge in mushroom growing is to respond adequately to everchanging cultivation conditions and still end up with good, or even better, results.

C o pr py ot ri ec gh te t d

â&#x20AC;&#x2DC;Mus hro o m g ro w i ng i s an ar t .â&#x20AC;&#x2122;

Mushroom Signals

A practical guide to optimal mushroom growing

Mushroom Signals

Mark den Ouden

Ta b l e o f c o n t e n t s Partners

2: Phase II, pasteurising and conditioning

• Ten Cate • Dalsem Mushroom Projects • Fancom • Hooymans Compost • Lambert Spawn • MC Substradd • Mush Comb • Panbo Systems • Sterckx • Verstappen Verpakkingen • Coenegrachts Substraat • Rubcoat • TMF Jobs

Conversion tables

Introduction 6

Mushroom growing worldwide 7 Mushrooms are good for you! 8 Fungi in the plant kingdom 9 10 The mushroom production process Composting and cultivation cycle 12 Composting 13 Various cultivation systems 14 On the mushroom farm 15

1: Phase I, fresh compost

Homogeneous 16 Selective 16 Straw 17 Horse manure 18 Chicken manure 19 Gypsum 20 Water 20 Phase I: Part one: pre-wetting 21 Wetting the straw 22 Recipes for homogeneous compost 23 Compost analysis 24 The most important data 25 NIR spectroscopy 27 Phase I: Part two: caramelisation process 28 Turning compost 29 Bunker 30 Traditional stack system 31 Example on/off schedule 32 Preparation for phase II 32 The environment 33

The tunnel 34 The tunnel principle 35 Filling a tunnel 36 The process 37 Spawn 41 Spawn vitality 42 Strains 43 Clean before spawning 44 Spawning 45

3: Phase III, spawn run

Mycelium development 46 Maintaining the compost temperature 47 Phase III in the growing room 48 Loading 49 Applying water before transport 50 Supplement 51

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ChampFood International Christiaens Group DTO Substrate - Walkro GTL Europe Mushroom Business Mushroom Office Amycel CNC EuroMycel Gicom Hoving Holland Limbraco Mertens - BonarAgro Mycelia ScatoPlus Topterra Holland BVB Substrates Hollander Spawn Sylvan

4: C asing soil and filling the room Casing soil Excavating black peat Various pore sizes Higher salinity = drier mushrooms Disease free Casing soil for export Filling the growing room Exclude possible vectors of disease Clean route and dirty route Hygiene during filling The filling machine How much water can compost take? Filling weight Watering on the filling machine Processing casing soil Surface of the casing soil

5: M ycelium growth and recovery

52 53 54 55 56 56 57 58 59 60 61 62 66 67 67 68 69

Mycelium growth in the casing soil 70 Growing chart 72 Water for the casing soil 73 Compost temperature is leading 74 Fan speed 75 Ruffling 77 Recovery period 78 Clever steering of temperature and humidity 78

6: Mollier diagram

9: Harvesting

Peculiar properties of air 81 Various quantities in one table 82 Evaporation uses energy 84 Air as a sponge 85 Energy in the air 86 Absolute humidity 87 How a climate unit works 88 Cooling with warm air? 89 Control based on CO2 and RH after cool-down 90 Cooling 91 Dehumidifying 92 Humidifying 92 New systems 93 Measuring system for heat, moisture and CO2 94

The picking technique Swing as you pick Picking ahead The picking platform Right first time The stump Classifying by size Many types of quality Which mushroom to pick? Harvesting the whole day Post-harvest quality Semi-automatic harvesting Mechanical harvesting Processing

7: Cool-down

10: Harvest management

8: Flushes

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When is the time to start cool-down? Cool-down: itâ&#x20AC;&#x2122;s all in the timing! Pinheading Emergency measure during the first days after cool-down Pinhead out-grow Diseases Strains Compost temperature a vital factor

Climate during the first flush Mould infections Treating infections Watering mushrooms? Climate on the final day of the first flush How much water after the first flush? Mechanical harvest of the first flush Inbetween flush Climate during the second flush Third flush?

97 98 99

103 105 107 108 109

110 111 114 115 117 119 119 121 122 123 125

Long-term planning Altering the planning Production planning Coaching Management Optimal working conditions Working hours Changing rooms: third flush last! What is the picking performance? How many staff do you need? Not spreading but controlling Clothing Dealing with infection Re-usable containers Food safety Cook out to eliminate disease Emptying the growing room Cleaning

126 127 128 128 129 130 131 132 132 133 134 134 135 136 137

138 138 139 140 142 142 143 143 144 144 145 146 146 147 147 148 149 150 151

Answers

152

Index

153

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Introduction

Mushroom growing is a way of life Mushroom growing is literally a fast moving business: a mushroom doubles its weight within 24â&#x20AC;Żhours! Mushrooms are sensitive to a difference of a few percent of relative humidity (RH) and half a degree Celsius difference in the air temperature has a huge impact on the extent and spread of growth. Mushrooms always grow too slowly or too quickly, you either have too many or too few. Despite the use of computers, inspecting the growing room morning and evening seven days a week, 365 days a year and making minor adjustments is absolutely essential. The temperature, air humidity (RH) and CO2 can be read out on a meter. But it is the signals you can detect in the compost and mushrooms in the growing room that really indicate where changes are needed. This book provides practical tips on how to optimally steer and control the quality, spread, moment of harvesting and production.

Not an instruction manual Mushroom Signals is not a HOW-TO instruction manual discussing all the details of mushroom growing, with tables showing the answers to every possible question. The purpose of this book is to stimulate readers to map out their own path. Conditions vary on every continent, in every country and on every farm. They can even differ within the same growing room. In mushroom growing there are many roads that lead to Rome. The answers and topics in this book are presented from a very practical perspective. The book also aims to encourage readers to observe and reflect, to be aware of the signals given by compost and mushrooms, to feel and smell and above all, to put this into practice every day!

Mushroom S i gnal s

Mushroom growing worldwide

The manager, together with an advisor, inspects the compost and assesses structure, humidity, smell and continually adjusts the composting process.

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China accounts for 70 percent of the global production of mushrooms, the greatest proportion of which are not white or brown mushrooms but exotic strains such as shiitake and oyster mushrooms. Ranking second in the world is the USA, while Poland and the Netherlands are considered to be the most important producers of mushrooms in Europe by far. In terms of efficiency, the Netherlands leads the field. The volume of mushrooms harvested per tonne of compost or per hour worked is high and the process from raw materials to harvested mushrooms is short. The low market prices realised for mushrooms over the past 15 years have increased the pressure on Dutch growers to maximise yields and efficiency on all fronts. This has created a high degree of specialisation among Dutch growers. In other countries, composting and growing are activities that often take place on one site. This enables growers to supply practically from farm to fork - without too many links in between - so the profit margin of the entire chain is generated within one company.

How are Dutch growers able to achieve such high production so fast?

Dutch mushroom growers hire a filling machine, together with the operator. The operator fills four to five growing rooms a day, five to six days a week. This makes the operator an expert on filling and the filling machine. The result is a perfectly filled growing room.

Springing up like mushrooms

Nothing illustrates the speed at which mushrooms develop better than these photos. The images were made at 24-hour intervals.

Day 1

Day 2

Day 3

Day 4

Day 5

Day 6

I n t ro d u c t i o n

The mushroom production process Phase I, making fresh compost Mixing of raw materials

Filling the bunker

Poultry manure

Horse manure

Straw

Process water

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Gypsum

Filling the growing room

MIXING

Mushroom development CO2

Compost temperature

Air temperature

Mycelium growth Filling the room

Start recovery

Start cool-down

Pinhead formation

Pinhead out-grow

Harvest

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Phase II, pasteurization and conditioning Compost temperature during phase II Levelling Pas Warming up teurising Cooling dow n

Conditioning

Cooling for

Mixing spawn through the compost

spawning

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Filling the tunnel

Phase III, spawn run

Emptying the tunnel

16 days: Full grown compost (phase III compost)

8 days: Spawn run in progress

1st day: Spawnable compost (phase II compost)

Cook-out, emptying and cleaning

Harvesting

1st week 1st flush 50% production

I n t ro d u c t i o n

2nd week 2nd flush 35% production

(â&#x20AC;&#x2020; 3rd week 3rd flush 15% production)

Phase I: Part two: caramelisation process gen content. The temperature pattern will indicate whether there is enough oxygen. With sufficient oxygen supplies, the temperature will rise in the beginning and stay at 80-85°C. If there is too much oxygen the compost temperature will rise initially but it will not increase to 80-85°C. Instead, at a certain moment the cold air being blown in will stop the temperature at 60-75°C. If there is too little oxygen, the temperature will rise initially, but once the oxygen levels become too low, this process will stop and the temperature will fall again.

The mixture looks dark yellow with all the blades coated with chicken manure. This is the moment that the next phase in the composting process begins. The compost is filled onto an aerated floor, outdoors or in a bunker to a depth of three and a half to six metres. This corresponds to a filling weight of between 1400 and 2200 kg/m2. Water is applied during filling. The fan is switched on after two to four hours. During this process, the fan is activated and deactivated at set intervals. At this stage the oxygen content of air is at least 8%. However, it is not necessary to measure the oxy-

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LOOK-THINK-ACT

What do these temperature graphs tell you?

60 55

40 35 30 25 20

65 60 55 50 45 40 35 30 25

Time from mixing/filling bunker (hours)

Temperature (°C)

Mixing + filling bunker

Temperature (°C)

Compost temperature

Mixing + filling bunker

Compost temperature

65 60 55 50 45 40 35 30 25

Time from mixing/filling bunker (hours)

Compost temperature

Mixing + filling bunker

Time from mixing/filling bunker (hours)

The temperature provides information about the oxygen level and the air supply. The left graph shows the optimal situation, the temperature continues to rise to 80-85°C. The centre graph shows the pattern with a lack of oxygen: the composting process stops and the temperature falls. The right graph shows what happens if air is blown too quickly through the compost. Enough oxygen, but the air cools the compost.

A bunker can be filled in three ways:

Overhead filler: The compost is filled horizontally and emptied vertically, this results in an optimal mix.

Bunker filler: Reasonable filling.

Loader: Cheap solution, but less than optimal for mixing and turning the compost.

Mushroom S i gnal s

Turning compost

How much water?

Inspection when emptying the bunker At emptying time, you should regularly inspect the compost for: -- Moisture content: how much water should be added at filling? -- Anaerobic compost: what you are looking for is patches of anaerobic compost. These are usually found about one metre above the floor: glassy-looking compost, lighter brown in colour rather than darker. If you measure the temperature at this point, it will be between 50 and 65Â°C. This is often the result of excess water being sprayed over the compost when the bunker was filled. Another cause could be compost staying in the bunker too long before turning, four to five days. During this time the pile has collapsed causing patches where air cannot penetrate.

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After three to five days in the bunker, the compost will have settled and the pile will have sunk in height by up to a metre. This makes it increasingly difficult to distribute air properly though the mass. Emptying the bunker and filling it again is like plumping up a flattened cushion. While being turned the compost is mixed again and water is added. This process is repeated two to three times.

Each time compost is turned, you add water. How much? -- Squeeze the compost and see and feel if water runs between your fingers. -- Compare different batches. -- Measure the moisture content in a laboratory. -- Consider how much water the mix can still hold without turning anaerobic. The maximum amount of water at the end of phase I, with a good structure is 75-76%. Donâ&#x20AC;&#x2122;t add water to the first layer in the bunker, up to one metre high, in order to prevent anaerobic compost in this layer.

Water in the compost

You take a handful of compost, it seems to be dry, and you canâ&#x20AC;&#x2122;t see any water. But appearances are deceptive: if you squeeze the compost, water will be forced out. The water is dark brown/black and syrupy and runs slowly between your fingers. Just before the phase II tunnels are filled, you should be able to squeeze lots of water from the compost.

Anaerobic compost

Anaerobic compost is visible in the photo on the left. There is no steam rising from it and it is more watery (glassy) and yellow in appearance. On the right you can see dark brown, steaming compost.

C h a p t e r 1 : P h a se I, f res h co m po s t

How much water can compost take? At filling you have assessed the compost for moisture content, structure, smell, colour, homogeneity and temperature. Added to information from the tunnel company, such as pH, measured moisture content and the number of days of mycelium growth, this should indicate how much water the compost can absorb.

Little watering required

Normal watering

Abundant watering required

Colour

Homogeneous

Reddish brown

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Dark brown

Black + yellow

Structure

Sticks together

Doesnâ&#x20AC;&#x2122;t stick completely

Reddish brown

Comes apart

Length

Moisture content 68%: feels moist

61%: feels dry

Mushroom S i gnal s

Watering on the filling machine

Growers aim for a certain filling weight, for example 90 kg/m2. The trailer full of compost arrives at the farm and unloads the compost onto the conveyor belt. How high should you set the dosing chain to obtain the desired filling weight? Assessing the structure/moisture content of the compost, speaking with the driver and/or the composting company, plus your previous experience provides good information about how to set the machine correctly. If the trailer looks emptier than usual, but the weight is right, and you judge the compost to be short structured and wet, set the machine to the minimum position, for example 24 cm. If the trailer is fully loaded, but underweight, and you judge the compost to be long structured and dry, set the machine to the maximum position, for example 36 cm.

The ideal conditions for applying water while the compost is on the machine are: 1. You assess the compost structure as good, so you can aim for a high filling thickness (e.g. more than 32 cm). 2. The compost is well incubated. The moisture content is 62-63%. Distributing the water properly is vitally important. How much water? The volume of water is always calculated regressively as the number of litres per m2 of growing surface area. For example: the growing room measures 340 m2, you have applied 1020 litres of water. This converts to 3 l/m2. Rule of thumb: every litre applied on the filling machine compares to 2 l/m2 if the water was applied in the growing room. You can apply up to 5 l/m2 of water on the filling machine. What is the advantage of applying water on the filling machine? Water is distributed throughout the entire layer of compost. Otherwise, if the casing is susceptible to sealing on the beds/shelves, the water doesnâ&#x20AC;&#x2122;t have to soak through this layer first. It isnâ&#x20AC;&#x2122;t always possible to water the compost on the filling machine. In winter, compost is often wetter and compost temperatures are lower. So, no water is added to the compost. However, if a supplement is added to the compost at filling, less water can be applied, with a maximum of 3 l/m2.

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Filling weight

Filling is food The filling weight of incubated compost is 80 to 95 kg/m2. The more compost you fill, the more nutrition per square metre. This creates higher activity in the compost. As long as this activity can be controlled, below the maximum temperature of 28Â°C, the nutrition in the compost will be available. If the temperature increases, plenty of useful nutrition will be lost. An advantage of a higher filling weight is that higher production and better quality mushrooms can be achieved in the second and third flushes. So a longer growing cycle and higher quality are easier to achieve with a higher filling weight of 90 kg/m2 than with 80 kg/m2. However, the yield per tonne of compost will be lower with a higher filling weight. For example: -- 90 kg/m2 compost gives 34 kg/m2 mushrooms = 377 kg per tonne of compost. -- 80 kg/m2 compost gives 31 kg/m2 mushrooms = 387 kg per tonne of compost.

supplement

water

The latest models of filling machines have scales that indicate the approximate filling weight. This is a very useful tool.

C h a p t e r 4 : C a si n g s o i l an d f i l l i n g th e ro o m

Not this way! Keep as large an interval as possible between the moment of applying water and adding supplement. Supplement and water do not make a good combination. In this situation they are being given practically simultaneously. 67

Evaporation uses energy

Wet-bulb The climate in the growing room is measured by two thermometers. One of these thermometers has a cotton wick. This wick hangs in a reservoir of water and is kept constantly moist. This is called the ‘wetbulb temperature’. The moisture in the wick continually evaporates, so this temperature is lower. As long as the wick is moist, this thermometer will indicate the evaporation temperature, comparable to the person stepping out of the swimming pool. The other thermometer measures the normal air temperature. There is often a fan in the room, so that the same volume of air is always blowing past the thermometers. By applying the temperatures from these two thermometers to the Mollier diagram, you can gain all the information, including the relative humidity (RH).

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After you have just enjoyed a swim on a sunny day and get out of the water, you feel chilly for about five or ten minutes until all the water on your body has dried. Then, you will feel warmer. Drying, the evaporation of water, uses energy. This energy is taken from your body. Evaporation in mushroom growing uses energy, thereby influencing the temperature of the bed and the mushrooms.

Rule of thumb: Do you want to quickly calculate the RH but you don’t have a table handy? Determine the temperature difference between the dry-bulb thermometer and the wet-bulb thermometer. Multiply the difference by 10. Subtract that number from 100. The result is the RH with an accuracy of +/– 1%. Example: (19°C dry-bulb 17.9°C wet-bulb) x 10 = 11. And 100–11= 89% RH.

LOOK-THINK-ACT

How can you determine the humidity of the air?

Read the temperature shown by the dry-bulb thermometer, for example 18°C. Read the wet-bulb temperature from the thermometer on the right, with the moist wick: 17°C. In the first column of the diagram look for the temperature: 18°C. Now take the difference between the dry and wet-bulb temperatures, in this case 1°C (18°C-17°C). Look up this difference in the top row. From this point trace a line vertically downwards. And from 18°C trace a line horizontally to the right. You can read out the RH at the point where the column and the row cross: 90%. The table was derived from the Mollier diagram. You can also look up the RH in the Mollier diagram using the dry-bulb and wet-bulb temperatures. Dry therm.

1½

2½

3½

100

dry-bulb

wet-bulb

temperature difference

wick

water

Mushroom S i gnal s

Absolute humidity (g/kg)

ulb

Temperature (°C)

r (° ete om rm the

A sponge is a good analogy to help explain how moisture and air interact. The sponge represents the air. In cold air, the molecules are closer together than in warm air. The closer the molecules are, in the air, the fewer the number of water molecules that can join them. The various points explained in the drawing correspond to the points indicated in the Mollier diagram.

t-b We

Air as a sponge

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Starting point A: Air temperature 25°C, 60% RH You can compare this to a sponge that is not fully saturated with water.

ith

ate

Point B: Air temperature 17°C, 100% RH The air cools to the dew point, the point where the air is saturated. No more water can be absorbed and water begins to condense from the air. Squeeze the sponge slightly and stop just before the water starts to drip. Now, if you pour extra water into the sponge, it will drip out just as fast as you pour it in.

Heat-

conte

nt (k

J/kg

)

ice

Point C: Air temperature 14.5°C, 100% RH The air at point B, with an RH of 100%, was saturated with water and could hold no more. Cooling to 14.5°C causes water to condense from the air. When you squeeze the sponge, water drips out.

C h a p t e r 6 : M o l l i e r di ag ram

End point D: Air temperature 25°C, 52% RH When the air is reheated, it will absorb more water. When you let the sponge expand, water no longer drips out. If you pour more water onto the sponge, you will see that it is able to absorb the extra moisture.

What grows and what doesn’t? Increasing numbers of pinheads appear on days six, seven and eight. You can now see how many pinheads are actually turning into mushrooms. Are there too many? Are they emerging at the same time? Do I have to steer the process? These are issues that growers, advisers and researchers alike are faced with. What is important is to (literally) have a clear picture of the optimal situation on each of these days. So, go into the growing rooms in the mornings and evenings and see what has changed compared with the situation during the previous inspection. Is the situation comparable to the previous growing room in the same phase?

RH 30%

CO2 10%

air temperature 60%

You can steer the growth of the pinheads using three climate variables: air temperature, RH and CO2. Temperature has the greatest influence, followed by RH and later CO2.

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Twiddling the knobs during pinning Similar to during pinheading, growers can still steer the size of the mushrooms to be harvested while the pinheads are continuing to grow. Air temperature has the biggest influence. The higher the air temperature, the fewer pinheads will grow into mushrooms. You can still make a difference even on days seven to nine. If the air temperature is set to 18°C, you can temporarily increase this value by 0.5°C for 12 to 24 hours. This will ‘freeze’ growth of the smaller pinheads (1-2 mm), while the larger ones (4-5 mm) will keep growing. It also works the other way around. If you think too few pinheads are growing

Factors that influence the number of pinheads

into mushrooms, reduce the temperature faster from 18 to 17.5°C. This encourages pinheads to grow into mushrooms. But watch out - if you increase the temperature again, you will disrupt the growth process again, so it is better to leave the air temperature at 17.5°C for the time being.

Assessing progress

Temperature x time

Pinhead out-grow can be steered well using the temperature. The higher the temperature and the longer this higher value is maintained, the fewer pinheads. And vice versa.

106

Mark one specific patch in the growing room and inspect it in the morning and in the evening. Use the camera on your mobile phone to take photos. This allows you to assess exactly the same pinheads so you have a clearer idea of how they develop. This gives you a detailed view instead of a helicopter view of the whole room.

Mushroom S i gnal s

Diseases Bacterial blotch Observation: Do you regularly notice bacterial blotch in the first flush, particularly on beds close to where air enters the room - usually at the front? Is the floor here still damp due to condensation in the air duct? Is this always where air enters the room? Reason: There is a big chance that the inlet air temperature is too low and the inlet RH is 100%. The climate computer will still try to humidify, but this is impossible. The water from the humidifier condensates at the start of the air duct. Recommendation: Increase the fan speed or increase the CO2 position.

Water blemishes

Clear signs of bacterial blotch.

C o pr py ot ri ec gh te t d

Small puddles of water on the floor where air enters the room are caused by condensation.

Observation: Water blemishes on larger mushrooms nine to 12 days after cool-down. At this moment it is a positive sign. There may be two different causes: 1. Mushrooms showing these blemishes are ahead of the rest of the first flush in development, so the RH in the growing room may be a little too high for these mushrooms. 2. The air temperature for the first flush is reduced from, for example, 18Â°C to 16Â°C. The RH should also decrease, in order to maintain the same evaporation levels (moisture deficit), but this is not happening, or not sufficiently (see Mollier diagram chapter). By the first day of harvesting the first flush, these blemishes should have vanished. They should have grown out of the mushrooms as it were. If they fail to disappear, there is a big risk of bacterial blotch developing.

These water blemishes are visible as glassy botches on the mushrooms.

If you place a mushroom cap on a torch, the light will clearly shine through the affected spots.

What causes internal stipe necrosis? Internal stipe necrosis is invisible externally on the mushrooms, but on the inside the mushrooms show brown discolouration or are almost rotten. This is caused by evaporation-related problems when the pinheads are developing into mushrooms. The pinhead has started to die due to too little evaporation, while in the heart of the mushroom growth has stopped altogether. Later on, when evaporation is at the right level again, the mushroom continues to grow, but the internal tissue has already died. Bacteria feed on the dead mycelium causing brown discolouration and corklike tissue.

C h a p t e r 7 : C o o l - do wn

107

CHAPTER 9

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Harvesting

In optimal conditions, a mushroom doubles its weight every 24 hours.

The mushroom must have space to grow. This space is created by pick-

Mushrooms grow at a rate of 4% per hour so picking at the right time is what represents the profit!

ing. Harvesting is more than just removing a mushroom from the bed,

slicing away the stem and placing it in crate. The true art is identifying the right moment to pick. Hairnet for food safety

Clean work clothing for good farm hygiene

Clean gloves for food safety

Scale to weigh the most harvested mushrooms immediately and put them directly in the consumer goods packaging.

126

Various types of packaging for the different quality classes

Picking rack with various types of packaging, so mushrooms can be graded as they are picked

Knife to remove the base of the stem, the stump

Waste bucket to collect the removed stumps

Mushroom S i gnal s

The picking technique Mushroom picking demands a certain rhythm and dexterity. Mushrooms are sensitive to damage, but an experienced picker can harvest them not only quickly, but also carefully. Pay attention to the following:

Take the next mushroom between your middle finger and halfway down your palm. Gently remove the mushroom from the bed with a twisting motion.

You can now slice straight across the base of the stem...

C h a p t e r 9 : H a r v e s ti n g

Gently remove the mushroom from the bed with a twisting motion.

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Hold the knife in your right hand. The bed is Take the first mushroom in your hand to your left. Pick the mushrooms with your left between the tip of your thumb and the tip of your forefinger and twist it. hand and cut away the stem with your right (if you are left-handed, the other way round).

Take the last mushroom using your little finger and the edge of your palm. Remove from the bed with the same twisting motion.

...And gently place the mushroom in the crate.

The cap of the mushroom must not touch your palm. The stem faces away from your palm.

Very experienced pickers can also pick a fourth mushroom (3rd between the ring finger and palm, 4th with the little finger). This is only possible if the mushrooms are not too large.

127

â&#x20AC;&#x2DC;Mus hro o m g ro w i ng i s an ar t .â&#x20AC;&#x2122; Mushroom growing is not an exact science. The true art is learning to see, interpret and correctly respond to signals. And that art can be mastered.

C o pr py ot ri ec gh te t d

ISBN 978-90-8740-136-8

9 789087 401368 www.mushroomoffice.com

www.roodbont.com

Mark den Ouden

Mushroom Signals

A practical guide to optimal mushroom growing

Mushroom Signals

Mark den Ouden