Volvariella, an important source of income

By Anton S.M. Sonnenberg, Research Unit Manager, Genetics, Breeding and Bioactive Compounds, Applied Plant Research, mushroom research unit, The Netherlands

The main agricultural products of Indonesia are rice, palm oil, coffee, tea, spices, sugar and natural rubber. For such a large country the production volume of mushroom is rather low. There are no reliable data on recent production volumes but it is estimated that the total production in 2000 was circa 60,000 tons. Approximately half of it is exported.

The production of mushrooms is almost completely concentrated on Java. Several species are produced, i.e. the rice straw mushroom (Volvariella spp.), oyster mushroom (Pleurotus spp.), shiitake (Lentinula edodes) and ear mushrooms (mainly Auricularia auricula). Ling Zhi or Ganoderma lucidum is produced on a small scale.

The majority of the producers are small farmers. There are only a few farms that produce white button mushrooms (Agaricus bisporus ).These are larger companies and most of their mushrooms are exported.

With the enormous demand for food, mushroom production offers a good opportunity for many people to improve their income considerably. An increase in production can easily be absorbed by local markets. The Indonesian government intents, therefore, to stimulate mushroom production, not only for the internal market but also for the export.

The HORTIN project

This intension is partly materialized in a recently started project, HORTIN, financed by the Indonesian Agency for Agricultural Research and Development (IAARD, Indonesia) and the Ministry of Agriculture, Nature and Food (LNV, Netherlands). Execution is vested in Plant Research International (PRI) and Applied Plant Research (PPO) in the Netherlands and the Indonesian Centre for Horticultural Research and Development (ICHORD).

One of the projects within HORTIN intents to improve the production of mushrooms in Indonesia. In order to support especially the smaller farmers, a cooperation is started between PPO and one of the institutes of ICHORD, i.e. the Indonesian Vegetable Research Institute (IVEGRI) in Lembang, Java. One of the goals of this program is to raise a research group at IVEGRI that can serve as a support for the mushroom producers and helps to further develop mushroom industry in Indonesia.

One of the problems in cultivation of mushrooms in Indonesia is the poor quality of source materials. Especially strains and inoculation materials for substrate (spawn) is of suboptimal quality. There are no local spawn suppliers and import of spawn is expensive. IVEGRI will set up a collection of strains for edible mushrooms that can serve as a reliable source of inoculum for spawn preparation. Next to this, IVEGRI will test different spawn and substrate formulations in order to improve the production levels.

At the start of the program several mushroom farms were visited by the Indonesian and Dutch project leaders. Here, an impression is given of the cultivation of the straw mushroom (Volvariella spp.) on Java with a large company and an association of small growers as an example.

PT Tuwuh Agung

The largest producer of straw mushrooms is PT Tuwuh Agung, a company near Yogjakarta, central Java. This company produces the species Volvariella esculenta. The site is very large and contains more than 350 sheds of considerable sizes (estimate more than 50 metres long, 5 layers in two rows). Only part of these sheds are used, with a total production of 10/12 tons a day.

The mushrooms are grown on compost made of rice straw as bulk material, supplemented with wastes of cassava, cotton or kapok. Chicken manure is also added as an important nitrogen source. Compost is made outdoors and pasteurised in the sheds by steaming. Compared to the white button mushroom the production cycle is short.

The company has a one on one relationship with the canning factory nearby in Yogjakarta where all mushrooms are canned and exported. This is an enormous advantage for this company, since the paddy straw mushroom has a short self life and has a lower price on the local market.

PT Tuwuh Agung produces also white button mushrooms (A. bisporus) with success. It is experimenting to recycle spent substrate of Volvariella cultivation in compost for the cultivation of the button mushroom.

Near Karawang

Volvariella species are very suitable for cultivation in warm areas and can be grown on small scale with low investments. It is, therefore, an excellent source of income for small farmers. A good example is the region near Karawang, east of Jakarta that harbours approximately 3000 straw mushroom farmers. Most farmers do not have more than one simple growing house made out of bamboo. They are very often organised in groups with a cooperate marketing of mushrooms. One of these groups is counselled by Dr George Surya Adinata of Pt. Tata Agro Nusantara Indah. He has taught groups of farmers how to build growing houses, to make compost and to grow these mushrooms.

The growers in the warm Karawang area (average temperature: 33 degrees Celsius) all grow Volvariella diplacia, a white straw mushroom. Because of the high temperature the cultivation is very fast. Since the region is known for its production of rice, the bulk ingredient for compost, i.e. rice straw, is easy to obtain. Additional ingredients that are used for composting are rice bran, gypsum and waste of cotton.

Raw materials are mixed and composted in a short time. While composting (six days), temperature goes up to 60 degrees Celsius and the heap is covered to prevent drying. The heap is mixed and watered every two days. Substrate is then transferred to a growing house and covered with coconut fibres. Growing houses consist of five layers in two rows. The space between the layers and the thickness of the substrate in each layer is chosen in such a way that each layer has approximately the same temperature, despite the lack of climate regulations. Substrate is pasteurised in the growing house for six hours at approximately 60 degrees Celsius. For this, farmers use a drum filled with water and heated by a fire under the drum. Three drums are used for one house. The steam is led into the house by a hose. Spawn is distributed on the substrate and spawn run for one week. After vegetative growth, fructification is induced by aeration and letting in more light. Farmers harvest during 14-21 days, twice a day.

Source of income

For the poor regions, the production of Volvariella can be an important source of income. The investment for one simple and small growing house is between $100 and $150. Such a house has a production capacity of 2.4 tons a year. This gives a grower a year income (after subtraction of production costs) of ca. $1700,-. Whereas this is half of the average year income per capita in Indonesia it is still more than most of their neighbours earn. Moreover, since the cultivation of these mushrooms in one growing house is not a full day’s work, it often will be an additional income.

Investments in these areas to increase the production of straw mushrooms seems, therefore, to be a good way to improve the income of the local population. The local market can easily absorb a substantial increase of production. The organization of farmers in groups is an excellent way to do this.

The aforementioned group lead by Dr George Surya Adinata is a good example. Spawn is made by Dr George Surya Adinata in a well equipped plant. Growers are taught how to build their growing house, how to make compost and how to grow. There is even a short course for house wives how to grow Volvariella on a very small scale on banana leaves. The stimulation of the cultivation of Volvariella would also be a contribution to the environmental problems since now much of the rice straw is just burned which attributes to air pollution.

Other species

The HORTIN project will run for at least four years and intents also to initiate projects in which Dutch and Indonesian companies participate. In a next article we will report on other mushrooms species that are produced in Indonesia. Volvariella is just an example of a species that is grown here. A number of other mushroom species that are cultivated also have high potentials in becoming a source of income and being a good source of protein in a country with a fast population growth, that has a high demand for non-expensive food.