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close this bookSPORE Bulletin of the CTA No. 38 (CTA Spore, 1992, 16 p.)
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View the documentCrop protection for resource-poor farmers
View the documentMaking more of mushrooms

Crop protection for resource-poor farmers

The problems that face the small-scale or resource poor farmer in the world today are complex: yet in many developing countries it is these resource-poor farmers who have to produce not only enough food for their own families but also a surplus for the urban population. They also have to produce cash crops either for processing by local industry or for export. Foreign exchange earnings, as well as the livelihood of individuals, depend largely upon their efforts.

Recognizing that yields of resource-poor farmers" crops are much lower than those recorded in the developed world, and that pest damage is a significant contributing factor, CTA, in collaboration with the Natural Resources Institute of the UK, organized a seminar on Crop Protection for Resource-poor Farmers. This was held from 4-8 November 1991 at the Isle of Thorns Conference Centre, University of Sussex, UK and was attended by 24 delegates from ACP countries and a similar number of resource-persons from the EC and elsewhere. Most delegates represented research establishments or their country's ministry of agriculture.

The objectives of the seminar were to provide a forum to examine and evaluate pest management techniques ranging from traditional practices to 'western', high technology approaches; to consider the relevance and usefulness of the latter to resource-poor farmers; to identify which of the modern and traditional technologies are most likely to benefit farmers in the African, Caribbean and Pacific states; and to propose means of promoting them.

In his introduction to the seminar, Mr Alan Jackson of CTA called for vigilance in assessing the effectiveness of new technology, technology which frequently ran the risk of being too narrowly-based. He challenged delegates to consider the extent to which the activities of scientists were really helping farmers with their problems and added that technology which stays in the laboratory is of no use to farmers.

Commenting upon the necessity to put the farmer first when attempting to solve farmers' problems, Dr Robert Chambers of Sussex University, one of the keynote speakers at the seminar, emphasized that farmers' participation is crucial. He said that controlling pest damage was a good example of where farmers should have "a basket of choices" rather than be given a "package of practices".

Mr John Perfect of NRI said that the integrated pest management (IPM) approach to crop protection, should provide farmers with the opportunity to make that choice. He pointed out that IPM called for the minimum use of agrochemicals and the maximum use of natural, regulatory mechanisms. However, he stressed that since improved crop protection was essential in order to increase yields, the use of agrochemicals could not be ruled out and, in certain circumstances, may even be increased.

Dr Theresa Sengooba, the Director of Namulonge Research Station in Uganda, who gave the second keynote address, stressed that the crop protection technologies that are being developed for resource poor farmers should be feasible, socially acceptable, environmentally sustainable and, above all, economically beneficial to the farmer. She felt that economic threshold levels are under-researched in many developing countries. Although levels have been established for some pests of major cash crops such as coffee and cotton, there is a need to determine economic threshold levels on all major pests of food and cash crops. This would improve the value of monitoring information and disease forecasting, and would help to guide decisions on research priorities.

Many of the speakers presented examples of crop protection techniques that reduce the need for pesticides. Dr Nick Jago of NRI described how, in Mali, farmers protect their fields of millet by planting sorghum, which is less susceptible to grasshopper attack, around the boundaries. Again stressing the importance of cultural methods, Dr Julian Mchowa of the Ministry of Agriculture, Malawi, said that having a closed season for cotton as well as ensuring that all plant residues are burnt after harvest, helped to control red and pink bollworm. Farmers are also encouraged to plant varieties of cotton which are resistant to jassid attack and to avoid spraying with insecticides in the early part of the season so that populations of beneficial insects can increase. A similar programme is practiced successfully in Zimbabwe.

Classical biological control has a very high cost benefit ratio when the desired ecological balance between pest and predator has been achieved. However, as Dr Winfred Hammond of the IITA Biological Control Programme in Benin pointed out, vigilance is still required. He said that farmers in Ghana had been controlling the grasshopper damage to cassava by spraying with insecticide, a measure which was proving to be more effective at destroying the beneficial insects which control mealybug and green mite. He described how encouraging farmers to spray earlier, on the weed grasses where the immature grasshoppers develop, had reduced the quantity of pesticide required, protected the beneficial insects and had proved to be a more effective method of controlling damage.

The need for a broad view was expressed by many of the delegates present, not only when presenting papers but in the discussion groups that were formed to consider crop protection from the viewpoints of a resource-poor farmer, a research scientist and a policy maker. Summing up the feeling of the seminar, Dr Florence Wambugu of the Kenya Agricultural Research Institute said that IPM is the best method of controlling any pest or disease but that it does need very good coordination to be effective. She suggested that another aspect of IPM should be to train and educate so that traditional methods are not lost and can be integrated effectively with the use of resistant varieties, quarantine measures, disease forecasting and cultural, biological and chemical control. And she observed that women's groups were often the most receptive to new ideas.

At the end of the seminar, Alan Jackson (CTA) re-emphasized that scientists and farmers must work together far more often and over longer periods of time. And when policy-makers try to identify farmer needs, they must consult farmers themselves so that their indigenous knowledge of how to grow crops, and protect them from pests, is fully recognized.

Making more of mushrooms

Mushrooms, or edible fungi, are appreciated for their good taste and nutritional value by many cultures, but to a rather limited extent in most ACP countries. In many places they are collected from the wild, but it is possible to culture mushrooms, although to do so successfully their biology and growing requirements must be understood. It is to assist the wider understanding of the potential of mushrooms as a farm crop in ACP countries and their exploitation that CTA has co-published with the Transfer Technology for Development (TOOL) the practical Manual on mushroom cultivation.

Techniques of cultivation, species and opportunities for commercial exploitation in developing countries are described with case-histories, diagrams and illustrations. Some of the information has previously only been accessible to readers of Chinese and is available now for the first time in English.

Mushroom growing involves many steps, from selecting a suitable technique and strain to spawn manufacturing, growing the crop and marketing the final product. This manual on the cultivation of mushrooms in tropical situations covers general biological information about the nature of mushrooms, information on how to conduct a feasibility study, the commercial potential of mushrooms, and technical information on the cultivation of more than ten species of fungi.

In earlier times cultivation of mushrooms often failed because their biology was not understood. The first records indicate that the wood ear mushroom (Auricularia) was cultivated from 600 AD onwards. The cultivation of white mushrooms (Agaricus) started about 1650 in France. Cultivation spread rapidly after the second World War when reliable spawn (mushroom seed) became commonly available in a number of countries. However, most mushrooms are still currently produced in the western hemisphere and South-East Asia, especially mainland China and Taiwan, Malaysia, the Philippines and Thailand.

Mushroom growing has many advantages. No arable land is needed and agriculturaI wastes, such as straw, are converted into fertilizers and soil conditioners. Income is generated, because mushrooms have a high added value in comparison to other crops. An extra source of protein and valuable vitamins and minerals is added to local diets. In most cases a fast return on any investment is possible.

The Chinese have developed many methods of growing mushrooms with limited inputs and it is some of these methods described in this book that are published for the first time in English. These techniques can easily be applied in ACP countries also and a start has been made. Examples are Malawi, where the government has sent technicians to Taiwan to study Agaricus production; and Burundi, where the Chinese have recently started a commercial spawn enterprise.

The potential for using waste products as a growing medium or substrate may be particularly appealing to many ACP countries. Shiitake mushrooms can be grown on wood logs in mountains with broadleaf tree forests, on pasteurized corn cobs and on sawdust. A technique for growing mushrooms on coffee pulp waste developed in Mexico can be adapted for coffee growing regions in Africa, Jamaica or Papua New Guinea. Culture can be in beds or where the substrate is held in plastic bags. Spawn production is still one of the limitations for mushroom cultivation in Africa, Latin America and some parts of Asia. Suitable strains are hard to obtain and there are still too few strains available that are suited to high temperature climates.

However, some commercial strains from the Far East for low-input cultivation car now be ordered. Technical skills and c theoretical background are necessary to produce the spawn and accurate guideline: on producing various types of spawn are described in Manual on mushroom cultivation.

In general, literature on mushroom culture is expensive and is not aimed at developing countries. By making the information in this book available to extension workers in ACI countries, CTA is encouraging the further dissemination of knowledge on a crop with considerable potential to farmers in their own country through local media and in the own language.

The publication is available from CTA, free of charge, for ACP nationals.