UTILIZATION OF CORN WASTES FOR OYSTER MUSHROOM PRODUCTION

INTRODUCTION

Oyster mushroom is becoming an important crop in the Philippines. It is one of

the agricultural crops gaining popularity and importance commercially. The demand for

mushroom is evidently high especially in the urban areas where numerous hotels and

restaurants are located.

The oyster mushroom has a pleasant, oyster-like flavor. This mushroom grows in

bracket-like clusters on decaying tree trunks. It is almost stemless. The fleshy, tender cap

is 8 to 13 cm (3 to 5 in) across, tawny olive-colored when young, but fades with age

(Microsoft Encarta, 2006)

Oyster mushrooms are by far the easiest and the least expensive to grow among

the edible mushrooms. For small cultivators with limited budgets, oyster mushrooms are

the clear choice for gaining entry into the gourmet mushroom industry. Few other

mushrooms demonstrate such adaptability, aggressiveness and productivity as these

species of Pleurotus. Also, more than any other mushrooms, Pleurotus species can best

serve to reduce hunger in developing nations, and to revitalize rural economies.

It is a delicacy to numerous people due to its exceedingly high food value

particularly in protein, vitamins and minerals making it a good substitute for meat.

Mushroom cultivation in the region or province is very limited in spite of the

environment which is very suitable for mushroom production. This limitation is attributed

to not only to the improper dissemination of available information to the farmers but also

due to the lack of practical technologies which local farmers could avail of. Thus efforts

are needed to produce technologies which make use of indigenous materials, one of

which are corn wastes that could be used as substrate or the nonliving material or base on

which an organism lives or grows.

This study aims to:

1. Evaluate the performance of corncobs and corn bran as spawn (a mass of

fungal threads mycelium for starting a new culture of the fungus) materials for

oyster mushroom;

2. Evaluate the performance of this wastes as substrate for mushroom

production; and

3. Determine the economics of using corncobs and corn bran on spawn and

mushroom production.

REVIEW OF RELATED LITERATURE

Nutritional Content

Mushrooms are full of nutrients and can make a very important contribution to

human nutrition. Their protein content is highly comparable to some common vegetables.

Although they cannot compete with meat, fish and Eggs, their protein content is almost

equal to corn, milk and legumes and definitely higher than other leafy and root vegetables

and fruits (Quimio, 1997)

Quimio (1996) said as cited by Buya (1999), mushrooms also rank quite high in

their vitamin content. Although devoid of vitamin A, mushrooms contain significant

amounts of riboflavin, thiamine and niacin. They are also good sources of essential

minerals such as calcium and phosphorus. Low in cholesterol and calories, mushroom are

often referred to as “slimming food”

Cultivation

The nutritional requirements of obligate parasites are not fully known. However,

the requirements of the saprotrophs (those that feed on dead matter) and hemiparasites (or

semi-parasites) are have been investigated for the growth and reproduction of most fungi,

the nutrient solutions must contain the following: (Kaul, 1997)

a. Carbon source – usually a carbohydrate, glucose being most favored.

b. A nitrogen source – organic and inorganic sources of nitrogen are utilized.

Different fungi have different requirements.

c. A sulfur source – sulfur is required in small quantities, but is essential.

Sulfates are most satisfactory as a source of sulfur.

d. A phosphorus source – phosphorus is also essential and phosphates are

generally satisfactory as a source of phosphorus for fungi.

e. Certain metallic or trace elements – potassium, magnesium, zinc, copper, iron,

manganese are required in minute quantities for their optional growth and

reproduction.

f. Some fungi require an extraneous supply of vitamins.

With this information, a lot of studies were made to determine quality substrate

for growing mushrooms.

As stated by Serafica (1999), peanut and munggo pods as substrate performed

well in terms of growth, incubation and quality of spawn produced.

Lesino (1995) reported that composted pine needles + rice bran produced white,

very thick and fast growing mycelia. Also, the utilization of composted and uncomposted

pine needles for oyster mushroom production is not advisable because of the low

biological yield and biological efficiency resulting to a negative return on investment.

As revealed by Martes (1991), the utilization of rice straw-supplemented leaves of

chayote gave the highest spawn biological yield, biological efficiency and highest sales in

spawn and mushroom.

In the study conducted by Tudayan (1991), the utilization of the unsupplemented

banana stalks, banana midribs and rice straw as substrates for oyster mushroom spawn

and mushroom production are feasible because of the high net returns as indicated by the

high biological yield and biological efficiency resulting to a high return on investment as

compared to banana leaves supplemented with rice bran.

Balisto wrote that the “dapo-dapo” sawdust supplemented with either azolla or

rice bran maintained a yield superior to that of the ordinary sawdust supplemented with

rice bran. However, both of them were able to support mushroom growth due to their

ability to supply the optimum nutrition for the mushroom.

Olanio (1995) found that tiger grass seeds are good supplement to banana leaves

but not recommended to be used as pure substrate.

Nato (1995) as cited by Gambala (1999), showed that scrap bond paper, pad paper

and Manila paper produced desirable quality in terms of thick, white and fast growing

mycelia. Thick, white but slow growing mycelia were observed on newspaper and rice

bran-supplemented sawdust.

MATERIALS AND METHODS

Spawn Production

Materials and Treatments

The materials to be used are corncobs, corn bran, rice bran, sawdust,

polypropylene plastic bags, alcohol burner, master spawn of Pleurotus, stapler and

laminar flow.

The treatments are:

T0 – Sawdust (80%) + rice bran (20%)

T1 – Corn bran (80%) + rice bran (20%)

T2 – Corncobs (80%) + rice bran (20%)

T3 – Corncobs alone

T4 – Corn bran alone

T5 – Corn bran + corncobs (1:1)

Preparation of Spawn Substrate

Collect corn wastes from farms and sundry. Chop these into uniform length i.e. 2

cm for convenience in drying as well as packing. Place all dried and chopped materials

in properly labeled containers. Soak these individually overnight in a barrel filled with

clean water. Allow these to drip before squeezing to reduce moisture content to at least

50%. After obtaining proper moisture, pack the different substrates in polypropylene

plastic bags (6 in. x 12 in.). Label according to the corresponding treatments. Seal plastic

bags by properly folding the open end and staple it. Sterilize by autoclave for 2-3 hours at

15 pounds per square inch (psi)

Inoculation

Allow sterilized substrates to cool and inoculate with previously prepared spawn

of P. sajor-caju. Do this aseptically under the laminar flow.

Incubation

Incubate the inoculated substrates inside a dark room with temperature maintained

at 24 – 28˚C until the bottom of the plastic bags have been fully saturated with mycelia.

Biological Yield

Open sample mature spawns to produce mushrooms in order to estimate expected

mushroom yield from each bag.

Data Gathering

The data to be gathered are:

1. Weekly growth of mycelia (cm) . This is measured as the height of mycelial

growth from the point of inoculation to mycelial until the spawn bags were

fully saturated with mycelial growth.

2. Spawn incubation period (day) . This refers to the number of days from

inoculation time to the time that spawns are ready to use as indicated by the

appearance of initials, i.e. the pinheads.

3. Spawn’s quality . This is described in terms of color, thickness of growth and

speed of growth.

4. Number of flushes . This refers to the number of times that mushrooms are

harvested from spawned bag which is allowed to produce mushrooms.

5. Total spawn biological yield (g) . This is the sum of mushroom harvested and

weighed from each spawned bag which was allowed to produce mushrooms.

6. Spawn biological yield (SBE) . This refers to the efficiency of the spawn

material to be converted into mushrooms, computed as:

SBE = Total spawn biological yield x 100%

Weight of spawn material

7. Return on Investment (ROI). All the expenses incurred are to be recorded.

The total sales from different treatments and return in investment (ROI) are

computed using the formula:

ROI= Gross sales-Total expenses x 100

Total expenses

LITERATURE CITED

BALISTO, D.N. 1992. Utilization of “dapo-dapo” sawdust as main substrate

supplemented with leaves of Leucaena glarica, Glirisidia sepium, Ventura spp.,

and Azolla spp., for oyster mushroom (Pleurotus sajor-caju) production.

Unpublished BS Thesis. Benguet State University. La Trinidad, Benguet. p.19

BUYA, J.T. 1999. Performance of cold-treatment Plerotus hybridus (gray) bags during

wet season. Unpublished BS Thesis. Benguet State University. La Trinidad,

Benguet. p. 4

GAMBALA, M.B. 1999. Cold Treatment of spawns and growing bags of oyster

mushroom (Pleurotus sajor-caju) Unpublished BS Thesis. Benguet State

University. La Trinidad, Benguet. Pp. 4-5

KAUL, T.N. 1997 Introduction to Mushroom Science (Systematics). New Hampshire,

USA: Science Publishers. p. 31

LESINO, J.P. 1995. Utilization of pine needles for oyster mushroom production.

Unpublished BS Thesis. Benguet State University, La Trinidad, Benguet. p. 18

MARTES, N.A. 1991. Utilization of rice straw-supplemented indigenous highland

agricultural waste for oyster mushroom (Plerotus sajor-caju) production.

Unpublished BS Thesis. Benguet State University. La Trinidad, Benguet. Pp.

32-33

OLANIO, N.W. 1995. Utilization of tiger grass as supplemented to banana leaves for

oyster mushroom production. Unpublished BS Thesis. Benguet State

University. La Trinidad, Benguet. p. 18

QUIMIO, T.H. 1997. Let’s Grow Mushrooms. Los Baños, Laguna: The UPLB Meseum

of Natural History at Los Baños College, Laguna. p. 2

SERAFICA, E. A. 1991. Evaluation on indigenous farm wastes for oyster mushroom

(Pleurotus sajor-caju) spawn production. Unpublished BS Thesis. Benguet

State University, La Trinidad, Benguet. p. 31

STEVENSON, J.A. and P.L. LENTZ. 2005. Mushroom. Microsoft® Encarta® 2006

[CD]. Redmond, WA: Microsoft Corporation

TUDAYAN, R.K. 1991. Utilization of banana wastes for oyster mushroom (Pleurotus

sajor-caju) production. Unpublished BS Thesis. Benguet State University.

LaTrinidad, Benguet. Pp. 25-26