Proposing alternative substrates to sugarcane bagasse to the Oyster Mushroom (Pleurotus) cultivation sector in Mauritius

P. Huzar Futty Beejan, R. Nowbuth

Food and Agricultural Research and Extension Institute,

Réduit, Mauritius

17 November 2018

Oyster mushrooms

• Edible mushroom

• Naturally occurring on dead logs

• Food

• Eaten both raw in salads

• Cooked in various ways

• Tasty

• Suitable for Vegetarians

• Second most cultivated mushroom in the World

• Most cultivated - Agaricus

Oyster mushroom-Nutritive and Medicinal Value

• Nutritious• Minerals: zinc, iron, potassium, calcium, phosphorus

• Vitamins: vitamin C, folic acid, niacin and vitamins B

• Fiber

• Proteins

• Low fat

• No cholesterol

• Medicinal • Used 3000 yrs ago in traditional Chinese medicine

• Tonic for immune system, dia.betes, cholesterol..

• Anti-oxidant (decrease cholesterol, improve immune system)

• Anti-bacterial effect

• Anti-cancer properties

Oyster mushroom in Mauritius

• Cultivation started late 80s

• Import value MUR 112 million/year (all incl.) and increasing trend• Fresh/chilled, dried, canned & processed

• Increasing local consumption due to• Use in local cuisine

• Highly appreciated

• Culinary attributes

• Nutritive value –various amino acids, vitamins, fibre & low fat content

• Functional food – medicinal properties

• Production using Fruiting bag

• Substrate for Cultivation

Currently commonly utilised• Sugar cane bagasse

• Formulation 80 % dry weight basis

Commercial Production in Mauritius

Production system using Fruiting bags

Sugar cane bagasse based Substrate

The Problem-Bagasse Availability

• At start of Mushroom Cultivation –bagasse free

• Bagasse for Energy Production

• Result in Increase in Cost• Prices variable

• Decreasing availability for Mushroom Sector• Availability periodic

• Factory availability

• Certification letter by FAREI for bagasse purchase

Sugar cane Bagasse

Bagasse Cogeneration Plant

Entrepreneur Constraint and The SolutionCONSTRAINT

• Bagasse availability

• Procurement sufficiency for planned production

• Changes in production volume

• Storage issues

• New entrepreneurs – bagasse procurement & Certification letter difficult as new agri-business

SOLUTION

• Replace bagasse

• FAREI research identified several possible alternative substrates

• Results presented to growers and public in Oct 2012

• Uptake by growers….increase due to price hike in 2018

FAREI Research Aim for support to mushroom sector

To identify an appropriate alternative substrate as a partial or complete substitute to sugar cane bagasse.

Objectives1. to identify alternative substrates for mushroom production.

2. to compare supplemented with unsupplemented substrate.

3. to formulate the substrate mixture for fruiting bag production.

Dissemination of Research ResultsTRM, Public Lecture, Recommendation Sheet, Visits, Training

Factors influencing choice of Alternative Substrate locally• Availability

• Rich in nutritive value

Mushroom yield determined by proportion of fibrous components (lignin, cellulose and hemicellulose) in substrate (Sharma, 1995)

• High yielding for grass species in terms of biomass

• Vigorous & rapid development and regrowth (rapidly renewable resource)

Testing of Wastes & Grasses in Mauritius

• Banana leaves

• Banana pseudostems

• Used coconut coir

• Pineapple leaves

• Wheat straw

• Maize stover

• Rice straw

• Cane tops

• Tea waste

Agro-waste

Total number of Wastes & Grasses tested > 21

No= 9

Source: FAREI

Source:Farmer

Source: Tea factory

Source:Vitagrain

• Palm trunk substrate

• Ravenal leaves

• Chipped wood

(Yatis and Goyave de Chine)

• Coconut hull

Other Wastes

Testing of Wastes & Grasses in Mauritius

No= 4

Source: farmer

Source: Collected

Source: Forestry

Source: farmer

• Cotton Yarn

• Carton

• Newspaper

• Sawdust

Industrial Waste

Pali Rao

Testing of Wastes & Grasses in Mauritius

No= 4

Source: Industry

Source: Purchase

• Elephant grass

• Guatemala grass

• Herbe Fatak

• Star grass

Grasses

Testing of Wastes & Grasses in Mauritius

No= 4

Source: FAREI

Composition of Potential SubstratesSubstrate CProtein

(%)C Fibre(%)

Ash(%)

Lignin Cellulose Hemicellulose

Banana lvs 4.8 30.1 13.5 10.6 34.8 13.6Bagasse old 2.4 37.1 16.1 24.3 44.3 0.9Fresh Bagasse 1.3 37.0 26.5 10.3 41.2 10.0Used Coconutcoir 5.7 37.1 21.7 45.0 35.6 ***Cane top 5.5 32.2 6.3 5.4 34.0 30.2Maize stover 7.5 24.3 4.0 3.8 25.8 26.0Fatak Grass 3.2 38.4 7.8 8.6 43.7 24.5Ravenale lvs 11.2 23.3 6.9 10.6 23.9 20.9Guatemala 10.0 30.4 9.3 4.0 33.6 29.4Star Grass 14.3 28.3 8.8 4.9 30.4 31.9Elephant Grass

9.8 33.1 9.1 5.8 36.4 26.7Rice Straw 4.1 29.9 9.1 6.2 43.2 25.4

Pretreatment Requirements Depending on the type of raw material, different pretreatment required prior to substrate preparation

1. Drying

Needed for coconut coir

2. Drying and chipping/grinding to required size

Grasses

Rice straw

Maize stover etc

3. Drying and Composting

Sawdust

Rice straw

Methodology of Fruiting Bag Production

1. Pretreatment of alternative substrate

2. Mixing of substrate

3. Filling of fruiting bags and Pasteurisation

4. Cooling of fruiting bags and Inoculation

5. Incubation

6. Fruit Induction and Harvest

Substrates Recommended

1. Grasses

• Star grass Cynodon plectostachyus

• Fatak grass Panicum maximum

• Elephant grass Pennisetum purpureum

• Guatemala grass Tripsacum laxum

2. Rice straw Oryza sativa

3. Other potential substrates e.g. cane tops, maize stover, wheat straw, banana leaves/Ravenale leaves, coconut coir

Grasses• Use of grasses that are easy to obtain

and easy to grow

• Possibility of cultivation to ensureavailability throughout the year or forharvesting, processing and storing foruse.

• Satisfy all criteria influencing choice ofalternative substrate

Dried Fatak Grass

Rice Straw• Source: Rice cultivation, private entrepreneur, Cluny

• Around 277 ha under production in 2012

• Straw left in field as mulch- approx. 2.78 tonnes/ha after mechanical harvesting

• Minimal drying required as at maturity tops almost dry

• Collection from the fields during harvest period

• Production suspended curently

• Banana leaves & Ravenale leaves

• Agro-waste from banana plantation, Ravenale from wild/marginal land

• Chipped banana leaves soaked for 12 hrs before substrate preparation

• Good substitution both in part & complete

• Maize stover

• Agro-waste consisting of stalk and leaves of maize plant left in field after harvest

• Dried and chipped before substrate preparation

• Good substitution both in part & complete

Other Potential Substrates

Soaked and Drained banana leaves’ substrate

Other Potential Substrates• Coconut coir

• Used coconut coir is a waste from hydroponic cultivation

• Satisfactory part substitution

• Cane tops

• The tops of sugarcane make up around 18-20% of the total biomass of the plant

• Used as fodder; for production of compost

• Available loose or in bales (mechanical harvesting)

• Chipped before substrate preparation

• Good as alternative both in part & complete substitution to bagasse

• Wheat Straw

• Straw left over after trials

• Chipped before substrate preparation

• Good substitution both in part & complete

Results Supplemented Formulations

Average Yield(g)/fruiting bag of 0.75kg capacity

Fruit Quality

Star Grass 105-238 Acceptable

Fatak Grass 167 Acceptable

Elephant Grass 151-174 AcceptableGuatemala Grass 151 AcceptableCanetops 142 AcceptableBagasse (Control) 150-180 Acceptable

3: 1 Bagasse: Guatemala Grass 161 Acceptable

Ravenale leaves (note: 5% suppl) 142 Acceptable

1: 1 Bagasse: Fatak Grass 132 Acceptable

1: 3 Bagasse: Fatak Grass 102 Acceptable

Maize Stover 57 Acceptable

Rice Straw 55 Acceptable

1: 1 Bagasse: Wheat straw 53 Acceptable

3: 1 Bagasse: Star Grass 53 Acceptable

3: 1 Bagasse: Elephant Grass 47 Acceptable3:1 Bagasse:Tea waste 56 Poor3:1 Bagasse: Coconut coir 52 Satisfying

Results• Time taken for colonisation generally comparable to

bagasse

• Exceptions: Manually chipped/larger sized substrates (e.g. banana leaves etc) take longer time for colonisation than bagasse control

• Highest yield of mushrooms obtained using Star grass substrate

• Part substitution using alternative substrate also promising

Substrate Procurement for Mushroom Agribusiness

Three Options for the entrepreneur- Collect,

Cultivate, or

Purchase • Purchase (indicative prices) without pretreatment

• Mixed grass : MUR 850/T fresh

• Single grass: MUR 2000/T fresh

• Others e.g. Bale Cane tops: Rs 700/250 kg bale

Used coconut coir: MUR 10/bag

(transport cost to be taken into consideration)

Growers’ Mushroom Production on FatakGrass at Cascavelle, Mauritius• Large scale mushroom production/on farm trial

• Chipped on site

• Use of fatak grass in part and complete substitution to bagasse

• Standard supplementation

• Good mycelium development

• Fruit of very good quality

• Yield obtained • 1Bagasse:1 Fatak substrate mix -average weight per 750g fruiting

bag=132g

• Only bagasse or Fatak fruiting bags comparable=91g

Substrate Preparation

Chipped Fatak

Production of Fruiting bags using FatakGrass

• Bagasse unavailable in Rodrigues

• Use of alternative substrates for mushroom production pioneered in year 2008

• Collection of substrate and manual chipping

• Substrate preparation

• Good fruiting flushes

• Mushrooms of good quality

• Status: No production currentlyInterest indicated- Scope for agri-business

Production on Banana Leaves & FatakGrass by growers in Rodrigues

Oyster mushroom cultivation in Rodrigues

Conclusion• Use of alternative substrates to bagasse possible but

choice depends on their availability• Range of alternatives (Agro-wastes, Grasses & other

Wastes) • Straw, stover, cane tops, banana leaves, grass

[collected from wild or/and cultivated]• The substitution of bagasse in substrate production• Part substitution-incl. coconut coir

• Complete substitution

• Depending on substrate, pretreatment requiredChipping/grinding of larger sized alternative substrates prior to use

• Use of Elephant, Guatemala, Fatak & Star grasses as viable alternatives

(both in part and/or complete substitution)

• Elephant grass-most promising cultivated grass in terms of biomass produced (Average yield=163 g/750g fruiting bag)

• Rice straw alternative with good potential

Conclusion

Acknowledgements

• Ministry of Agro Industry and Food Security, Mauritius

• Food and Agricultural Research and Extension Institute, Mauritius

• CEO, FAREI

• Equipe QualiREG