Fusarium and Verticillium wilts are two of the most serious diseases of cotton, which exist along the coast of the Yangtze river. About 20-40% of the potential output is lost due to cotton diseases and insects in Jiangsu every year. There are three pathogenetic strain types of Fusarium oxysporum, F. vasinfectum and Verticillium dahliae in Jiangsu. Studies had been conducted to determine the range of host plant of cotton Fusarium and Verticillium wilt pathogens, and to synthesize an integrated control technique of the two diseases, which included technical method of thoroughly disinfecting seeds, and the use of resistant varieties. These two diseases are now being controlled in Jiangsu province [China]

Bacterial blight and black arm, caused by Xanthomonas campestris pv malvacearum, are serious diseases of cotton. Using cotton lines as differential hosts, the organism was identified as Race 14. A total of 136, 92 and 77 cotton lines and varieties were screened against bacterial blight, black arm and bacterial boll rot, respectively. Of these, 57 were rated highly resistant and 38 were resistant to bacterial blight; 38 were highly resistant and 27 were resistant to black arm. None of the 77 cotton lines and varieties evaluated for resistance to boll rot showed resistant reaction. The correlation between the resistance of the leaf, stem and boll to X. campestris pv malvacearum was determined. No close correlation existed between the resistance of the leaves, stems and bolls on 60 cotton lines and varieties evaluated. A close correlation, however, was noted between leaf and stem resistance on 38 lines.

The Tropical Agriculturalist In many developing countries, particularly in Africa, there is a great shortage of middle-level technical books and manuals suitable for advanced agricultural education or extension services. Because of the specialised nature of their content, these books have a limited market and consequently, limited sales. They are therefore not a very attractive proposition for publishers in Africa where the problem is aggravated by poor purchasing power and exorbitant production costs. 'The Tropical Agriculturalist' series is designed to fill this gap. These are practical field guides and manuals on major tropical Crops and cultivation practices, co-published by CTA and Macmillan. They are translations of original French texts commissioned and co-published by CTA, ACCT, and Maisonneuve et Larose in a series entitled 'Le technician d'agriculture tropicale' (see Spore No. 9 for more details). The text is written in a deliberately simple style and is supported by clear illustrations which greatly facilitate their use in the field. These books are designed for agricultural students and teachers, but are also useful for extension workers, farmers and farm managers. The following three titles have recently been published. MAIZE by Guy Rouanet Better seeds and improved ploughing methods alone are not sufficient to ensure good maize harvests. The farmer also needs to be aware of other factors such as environmental requirements and the control of pests and diseases. This book reviews the plant structure and life cycle of this very important tropical food staple, its environmental requirements and major cultivation systems. It also includes a review of both traditional and modern cultivation and storage methods and suggests ways to adapt them to varying ecological conditions. PLANTAIN BANANAS by Hugues Tezenas du Montcel Cooking bananas, as opposed to sweet or dessert bananas, are an integral part of the diet of many people in the humid and sub-humid tropical zones of Africa and the Caribbean. It is estimated that between 30 and 50 million tonnes of bananas are consumed annually in these areas. This manual provides the reader with essential information on techniques for planting and maintaining plantations in hot, humid regions. Traditional cropping systems and techniques for intensive plantation maintenance are described, with an overview of input requirements and pest control. Summary recommendations on every page make this manual particularly appropriate for extension services or as a teaching text. STORAGE OF FOOD GRAINS AND SEEDS by Jean Appert Post-harvest losses due to rats, weevils, fungi and other pests account for a large part of the food deficit of developing countries. Proper storage of grains and pulses is therefore of great importance in reducing such losses. This book looks at strategies to adopt, precautions to take, and mistakes to avoid in storing harvests. It discusses the different causes of spoilage, their origin and nature, and the extent of losses. Traditional and modern storage structures are compared and an illustrated description of the major pests of stored products is given. CTA recognizes the importance of these simplified manuals in bridging the gap between research results and their implementation in the field, and plans to publish further titles in this series. Volumes on cotton, cassava and weed control are under preparation and CTA is considering expanding the series to include livestock production. Available from: Technical Division CTA Postbus 380 6700 AJ Wageningen The Netherlands | The Tropical Agriculturalist [series] MAIZE / by Guy Rouanet PLANTAIN BANANAS / by Hugues Tezenas du Montcel STORAGE OF FOOD GRAINS AND SEEDS / by Jean Appert

Poultry farming may provide an answer to the problem of nourishing the rapidly increasing populations in developing countries, especially those with mushrooming urban areas. To help meet the food needs of city dwellers, battery farms modelled on those in industrialized countries have been developed over the last twenty years with considerable success. Poultry farming in rural areas, however, remains highly traditional and has hardly been improved despite the fact that it still provides the bulk of production. Although most farming households in Africa generally keep a few chickens, poultry breeding remains for them only a secondary activity. It simply enables some ready cash to be brought in when needed by selling off a little of the capital that such birds represent for most farmers. Of more importance is the social significance of such flocks, given the fact that chickens are traditionally used as presents or tokens of exchange and make up the main dish that is served during certain festivities. Poultry consumption in rural areas is however, generally limited to such festive occasions and is estimated to be no more than one or two chickens per person per year. As for eggs, their consumption is severely limited by food habits and certain taboos. Under these conditions, poultry farming remains a supplementary source of income and thus must not incur any additional costs. It is almost like having a flock of wild birds as there are no breeding costs and they maintain themselves on readily available resources. These free-range chickens feed on kitchen waste, crop leftovers, grain residues, insects and some grass in the rainy season. Farmers occasionally trap termites for young chickens, but it is extremely rare to feed them grain. The birds are left to roam during the day, either within or around the yard. At night, they are kept inside wattle or straw roosts which are often very small, badly aired and rarely cleaned or repaired. Birds of different species and ages are bunched together indiscriminately under conditions favouring the spread of diseases. Furthermore, eggs are hatched without supervision and are seldom collected. Under these conditions poultry farmers suffer high losses. The birds are attacked by predators, eggs get broken or lost, and chicks often die before they are two months old. Their numbers are regularly reduced by parasites and respiratory diseases. Viral infections such as Newcastle disease are particularly common during the dry season. Their numbers also fluctuate considerably, being higher during the rainy season when climatic conditions are more favourable, and lower during the dry season when mortality is higher and more of them are sold. Most of these flocks consist of native chickens which have long interbred with European breeds. They are generally known as 'African chickens','running chickens' or 'country chickens'. They are usually small and of various colours, and they weigh approximately one kilo when they are sold at the age of six to eight months. A hen lays between 50 and 90 eggs a year. Although such production is relatively low, these birds have the advantage of being very sturdy, resistant to tough climatic conditions and good breeders. Apart from chickens, one also finds guinea fowl that have been domesticated from the various wild strains of the savannah regions. Their genetic adaptation to the local environment is very important under such farming conditions. In order to improve productivity attempts have been made to replace local cocks with improved western breeds, such as Rhode Island or Plymouth Rock. Such initiatives, which began in French-speaking Africa over a decade ago, have not always lived up to expectations. It has not been easy to reach all poultry farmers and thus to eliminate all the local strains of cocks, especially as farmers often prefer to keep birds of different types and colours to meet particular social requirements. In fact, genetic improvement alone will not bring about a substantial increase in production. It must be combined with effective sanitation measures and improvements in feeding and health care. Closer supervision, especially during and after incubation, would also cut losses. The use of better and regularly cleaned hen roosts, the isolation or elimination of sick birds, and the quarantine of new arrivals, would also considerably reduce the incidence of disease. Some NGOs are thus promoting more appropriate roost designs that are easy to build with local materials. Regular vaccination is also necessary to fight epidemics which can destroy entire flocks almost overnight. If farmers are going to increase their poultry production significantly, they must drastically change their feeding methods. This will require educational campaigns to convince them that it is in their interest to feed their chickens. But this is only possible if their other operations provide enough surplus grain or if they can afford to buy commercial feed. This is a feasible proposition as such chickens generally sell well, either directly on local markets or to middlemen who buy on behalf of urban merchants. In fact, free-range chickens are highly valued by urban consumers who prefer them for traditional, stewed dishes. In Dakar, for example, demand often exceeds supply and free-range chickens fetch a higher price than battery chickens. But if poultry farming is to be profitable, transportation methods will have to be improved. Live hens in exposed cages stacked on the roofs of taxis, or hanging by their feet from bicycles or motorcycles, are often the worse for wear, if not dead, on arrival. Those that do survive must then face the poor handling conditions of the markets. Nevertheless, local breeds still account for the bulk of poultry production in Africa, varying from 70 % to 90 % depending on the region. Production in large, modern battery farms is now increasing rapidly in many countries, notably in Cote d'lvoire and Cameroon. This sharp growth in battery farming, supported by governments anxious to supply urban areas and to reduce meat shortages, has been stimulated by numerous financial incentives. Battery chickens differ from local breeds not only in taste, but even more so in their cultural requirements which are similar to those used in Europe. Such intensive poultry farming is most often located on the outskirts of large cities. In Cote d'lvoire, for example, 90 % of this type of farming is concentrated around Abidjan with practically none in rural areas. The smallest of these battery farms have only a few hundred birds, use improved breeds and buy part of their feed. They are owned by city dwellers, merchants or state employees who use them to supplement their incomes. Intensive poultry farms are hardly ever owned by small farmers, except where charitable organizations or NGOs have provided financial assistance. Since few of the operators have been specifically trained for the job, feeding and sanitation standards are often DOor. Huge battery farms also exist, housing thousands or tens of thousands of birds. These are sometimes known as 'chicken cathedrals' and have been set up by large European firms. The largest of these operate as completely integrated concerns with the same company taking care of everything from hatching to sale, including feed and medecine supply slaughtering and marketing. Others are only partially integrated feed stuff, chicks and training are provided, but the farmer is in charge of everything else, including market~ng. All of these farms use improved genetic strains. Chicks are provided from breeds which have been especially selected for egg or meat production. Other commercial criteria, often of a psychological nature, such as the colour of the eggs or feet, are also taken into consideration. Rhode Island hens, which produce coloured eggs, are highly valued in West African countries. A more important factor is the use of breeds that are adapted to both the climate and the type of feed provided. Those that come from the few major world breeders often do not have characteristics appropriate to tropical environments. Large goodlaying hens, for example, suffer from the heat. Much better are small hens, such as the 'Vedette' with its dwarfism gene, or bare neck hens, which adapt more easily to high temperatures. It is also advisable to choose birds with a sound appetite that will ensure an adequate food intake even when hot weather reduces the desire to eat. Although the use of incubators has spread recently in most countries, there are often still not enough to be able to provide battery farms with adequate supplies of day-old chicks. They thus have to be flown in from abroad which is very expensive and risky. Those chicks that do survive the stressful journey often arrive in such a state that their initial growth is severly compromized. These battery farms use feed which is prepared locally but consists of a large proportion of imported ingredients to which locally available raw materials are added wherever possible. The use of soya and maize cakes, minerals and vitamins from Europe or the United States results in a considerable drain on foreign reserves and problems of storage and supply interruptions. Imported raw materials account for nearly 50 % of the cost of a chicken. The same is true for medicines, which are rarely produced entirely in the country. On the other hand, local resources are often under-exploited and little work has been done on how to make better use of them or how to ensure a higher and more consistent quality. Many products nevertheless deserve to be more widely used: cassava, molasses, rice by-products, copra and palm cakes and, of course, cotton or ground-nut cakes Many of these products go to waste, yet they could, to a large extent, replace imported products and increase the much needed self-sufficiency in feed stocks. African battery poultry farming thus remains highly dependent on foreign supplies and technical expertise. The building designs used are often copied from European models which are obviously not always appropriate for hot countries. It would be preferable to construct buildings which are better ventilated, have better heat protection, more drinking troughs and less densely-populated hen houses. Although African battery farms are considerably more productive than poultry farming in the countryside, they do not achieve the levels of productivity of European chicken factories as the birds fatten less quickly and lay fewer and smaller eggs. Heat and the rapid spread of microbial infections in humid regions are the main reasons for this. Productivity would be improved if battery farms were located in cooler areas such as uplands. In spite of some negative results, intensive poultry farming has developed spectacularly over the last decade as it remains the only way of rapidly meeting demand. However, prices are still high for the consumer and the commercial market, serving essentially Europeans and wellto-do Africans, is likely to become saturated unless prices come down. Moreover frozen chicken imported directly from industrialized countries is beginning to make considerable inroads on this same rich man's market. These products, heavily subsidized by the exporting countries, are often less expensive in ACP countries than locally-produced chicken. There has also been an increase in the production and consumption of eggs but their market does not extend beyond urban areas. Although modern poultry farming is capable of providing high protein food for towns, it is still too expensive and dependent on external factors. Applied research on the food value of local raw materials and the training of competent personnel are needed if self-sufficiency is to be ensured. At some time, traditional poultry farming, relying solely on local resources, is a potential source of considerable production. But it has so far been underestimated. increased information and extension programmes, improved sanitation, and better marketing and distribution networks would enable traditional poultry farming to make a more significant contribution to both the village and the national economy Such chicken production will never be able to meet urban needs, but the towns can become a real market for small producers who could obtain considerable extra income without competing with battery farms. What then is the solution ? Should one increase production in order to develop the market? Or develop the market in order to increase production ? It really isn't a question of which comes first, the chicken or the egg, but rather of the willingness to ensure that poultry farming is given a major role in projects and aid. BIBLIOGRAPHY: - IEMVT (1983). Manuel d'aviculture tropical - IEMVT, Ministere des Relations exterieures-Cooperation et Developpement. Paris. - Saunders M. J. (1984). Aviculture traditionnelle en Haute Volta - Assoc,ation Frangaise des Volontaires du Progres Projet developpement aviculture villageoise Ouagadougou. - Forssido, T. (1986). Studies on the meat production potential of some local strains of chickens in Ethiopia. Ph.D. thesis, Scientific Centre. Tropeninstitut. Justus Liebig Universitaet. Giessen. Germany. | Poultry farming may provide an answer to the problem of nourishing the rapidly increasing populations in developing countries, especially those with mushrooming urban areas. To help meet the food needs of city dwellers, battery farms modelled on...