|SPORE Bulletin of the CTA No. 31 - February 1991 (CTA Spore, 1991, 16 p.)|
New technique for producing hybrid seed
American and Belgian scientists have developed a technique for making it easier and cheaper to produce hybrid seed from any crop. Hybrid vigour can increase yields of some crops by 20% or more, so hybrid seed plays an important part in increasing food production.
Hybrid seed production has not always been commercially viable. When two crop varieties are selected as the parents for hybrid seed it is necessary to remove the male organs (the anthers which produce pollen) from the variety that has been selected as the female line so that self fertilization does not take place. The seeds that are then produced by that plant will be the result of cross fertilization with the other variety.
Removing or picking off the anthers by hand is easy in some crops, such as maize but it is labour intensive, for crops in which the anthers are small or inaccessible, it can be very difficult. This difficulty has seriously restricted the amount of hybrid seed available for many of the important food crops of the world, such as rice.
The new technique uses genetic engineering to ensure that selected crop varieties can be made male-sterile. They will be normal in all respects except that they will not produce pollen. The lining of the anther, known as the tapetum, is crucial to pollen formation. It is through the tapetum that pollen grams are nourished with proteins and other substances. The new technique destroys the tapetum. To do this the researchers add to the plant a gene that produces an enzyme which destroys the tapetum and leads to male sterility.
The basic work was carried out on oil seed rape. In theory, it should be possible to transfer the same enzyme-producing gene into any plant. If it does not work then it will be necessary to develop a gene specifically for that crop, but the researchers feel that will not be difficult now that the technique has been developed.
Department of Biology University of California Los Angeles,
California 90024-1606 USA
Plant Genetic Systems, NV J. Plateaustraat 22 B-9000 Gent. BELGIUM
Pastoral system rejuvenated
Turkana pastoralists have found that water harvesting has taken the risk out of growing sorghum. Indeed, in many years they can get two crops a year and food supplies are much more secure than they have been in the past.
After the severe drought of 1980 Oxfam and the Intermediate Technology Development Group began a project to improve food security m the area. Water harvesting techniques were introduced that were based on those developed thousands of years ago in the Sinai Desert. Areas of land subject to flooding or flash floods had metre high earth bunds built around them to trap the water. After the water had soaked in, a fast maturing variety of sorghum developed by the Turkana was planted and the wafer 'barked' in the soil was sufficient to carry the crop through to harvest.
In some years it has been possible to get two crops of sorghum as the short rains very often provide enough water to plant again. The pastoralists have never been able to do this before.
Another feature of the project has been the way traditional councils have participated in the project and taken over responsibility, this has improved their standing with local institutions and with the Government. The pastoral system is now considered to be the only viable use of the land in this dry area. Neighbouring districts are now using the same techniques to take the risk out of cropping.
ITDG Myson House, Railway Terrace Rugby CV21 3HT, UK
World Bank aids development project in the Congo
The World Bank has approved a loan of $15.8 million to help an extension and research programme in the Congo which will raise the productivity and income of small-scale farmers by increasing the development and dissemination of appropriate technologies.
The aims of the project are to set up a national network of agricultural extension and adaptive research, to improve coordination on the ground of all technical services for farmers, and to develop closer links between extension and research. The project is primarily targeted at women and younger farmers who play a crucial role in agriculture. The Congolese Government, the European Development Fund and the United Nations Development Programme are also contributing to the project.
The World Bank, 1818 H Street, Washington OC 20433, USA
CTA will distribute catalogue to ACP countries
CTA has agreed to buy 100 copies of the printed union catalogue of serials in 14 International Agricultural Research Centres (lARCs), for distribution in the ACP countries. The catalogue is the result of work done by L J Haravu, former Information Officer at ICRISAT and now ILCA's Head of Information. Before he left ICRISAT he completed phase 1 of a project to produce camera-ready copy for the catalogue, and a micro CDS/ ISIS database of the union catalogue. This also has software which automatically generates inter-library loan/photocopy requests based on the database. This should provide wider and easier access to IARC serial resources and will improve document delivery.
L J Haravu Head of Information ILCA PO Box 5689 Addis Ababa ETHIOPIA
African loss of soil fertility
An FAO study reveals that the loss of soil fertility in some African countries is so rapid that food production targets will not be met by the end of the century unless land management techniques improve drastically.
FAO scientists studied soil fertility in 38 sub-Saharan countries in order to establish the amount and rate of loss of the primary plant nutrients, nitrogen, phosphate and potash, set against the inputs of mineral fertilizers, manure, rain and dust deposits, biological nitrogen fixation, and sedimentation.
The result was that these countries suffered net losses each year which were described as 'awesome" - up to 60kg of nitrogen per hectare, 25kg phosphate / ha and 60kg potash/ha. The situation will be redeemable only if improved land management uses chemical fertilizers more efficiently, leaves crop residues, and minimizes leaching and erosion.
FAO Via delle Terme di Caracalla 00100 Rome, ITALY
Working to reduce post-harvest loss
Recent studies have shown that post-harvest losses in cassava crops occur in processing rather than in storage.
The International Institute of Tropical Agriculture (llTA)'s Post-Harvest Technology Unit has carried out surveys on how to eliminate loss at the family processing levels, and on how to increase the productivity of the women who do most of the processing in rural areas. The loss per family averages 2200kg per 10 tonnes/hectare, equivalent to 2954 man hours per ten tonnes per hectare.
IITA is encouraging the establishment of village processing centres where fresh cassava tubers are weighed and are given in exchange for already processed food, produced on the spot with the aid of simple and appropriate technologies. Standard measures would be available to gauge the weight of the finished products, which are produced under hygienic conditions. Dr Y W Jeon of IITA says this technology will help check food loss, encourage cooperative development, raise the standard of living in rural areas, and free women for other activities.
Similar centres for the processing of soybeans have already been set up by IITA at Ijaiye near Ibadan, and any profits made there are used to improve and equip the centre. All local women may bring their food crops there for processing in exchange for the finished product. Other centres, such as that at Moniya, have a biogas generating unit incorporated.
Dr Y W Jeon Post-Harvest Technology Unit IlTA PMB 5320 Ibadan NIGERIA
Pulses improve the soil
Scientists at the International Crops Research Institute for the Semi Arid Tropics (ICRISAT) stated recently that chickpea and pigeonpea roots improve the soil by increasing the availability of phosphorus and the water infiltration rate. This is because chickpea roots exude large amounts of acid that dissolve calcium-bound phosphorus in soils, and pigeonpea roots discharge components that can release iron-bound phosphorus.
At an International Workshop on Phosphorus Nutrition of Grain Legumes in the Semi-Arid Tropics in January 1990, ICRISAT scientists, working on a project funded by the Japanese government, produced evidence that sorghum grows better after pigeonpea, and that pigeonpea does better after chickpea.
ICRISAT, Patancheru, Andhra Pradesh 502 324, INDIA
**AT ICRISAT has now been relaunched as SAT (Semi-Arid Tropics News, with a much wider-ranging field of interest, although it will still report items of ICRISAT news.
Cashews for cash
In five years' time Ghana's Upper West Regional Administration will have planted 100,000 cashew and other economically profitable trees in a project financed by the United Nations Development Programme.
The District assemblies in the five Districts of the Upper West Region will plant around one hectare of cashews and two hectares of other trees every year for five years, and will manage the plantations themselves ensuring as far as possible the survival of the saplings. They will be expected to export cashew nuts to earn some revenue to finance development projects. The other tree species will enhance urban districts.
Simon Abingya Deputy Regional Secretary Upper West Regional Administration PO Box 16 Wa GHANA
CTA's Question-and-Answer Service used to the full
Vincent Zigirinshuti runs a small food processing factory in Rwanda, and when he wrote to CTA's Question-and-Answer Service, he was sent all information relevant to making powdered soya milk.
Mr Zigirinshuti used this information to market a baby food powder made of powdered soya milk mixed with dried cow's milk and sorghum flour, and flavoured with fruit juice. It appears the young consumers cannot get enough of it!
Mr Zigirinshuti, true to the ideals of Spore, wishes to pass this knowledge on to anyone interested in manufacturing this baby food. His next request to CTA was for leaflets explaining how to set up a small-scale sugar factory and no doubt Spore readers will soon be able to benefit from his experience in this venture also.
V Zigirinshuti ZM, BP 1740, Kigali, RWANDA
Sudanese farmers take to donkey power
In Darfur Province, west Sudan, donkeys are gradually becoming the main draught animal. This has been made possible because a chisel plough based on the ancient ard plough, has been developed especially for use with donteys.
Although camels have been used as draught animals in the area most of the cultivation work has been done by hand because although most families have donkeys, they have been used only as beasts of burden.
Three years ago the Intermediate Technology Development Group began the Kebkabiya Smallholders Project to encourage the use of donkeys as draught animals. Various designs of plough were tried including a mouldboard plough. But with low rainfall and soils that are prone to capping, it was felt that a chisel plough would do a better job.
The chisel comprises a winged tine which can cultivate to a depth of about 150mm, which is enough for millet. Also, it opens up the soil for good water penetration.
A suitable harness for the donkey has also been developed. It is made of nylon webbing which is available in the area. Local blacksmiths are being encouraged to make the plough. Costs are being kept to a minimum, about 30% of the cost of a bag of millet.
ITDG Myson House Railway Terrace Rugby CV21 3HT UK
Innovations for Development Awards 1990
Dr Reg Preston, a consultant to the Convenio Inter-institucional pare la Produccion Agropecuaria en el Valle del Rio Cauca (CIPAV), Colombia has been granted the IDEA award in the target area of farming The award is given by the Innovations for Development Association (IDEA), which is based in Stockholm, Sweden.
Awards have been given to prominent innovators in five target areas: Water, Energy, Forestry, Farming and Fishing. Prizewinners have been selected on the basis of the sustainability, self-reliance and socioeconomic acceptance of their innovations.
The prize was given to Dr Preston for his innovative use of waste from major crops and his utilization of by-pass nutrients which have the property of escaping fermentation in the rumen. Dr Preston's award is based on two specific feeding systems he has developed.
One system has been developed for intensive livestock production from sugar-cane and forage trees and IS targeted at resource-poor farmers in the Tropics. The second is a ruminant feeding system which provides a proper balance of essential nutrients in the products of digestion using the by-pass system. CTA is honoured to have been associated with Dr Preston's work. He is the author of three CTA publications: Milk production in the Tropics, Pigs and pou1try in the Tropics and Feeding cattle with locally available resources (with Dr Leng). He was also the main speaker at a conference on the last topic, the Proceedings of which have been published by CTA.
Dr Preston has also acted as consultans to CTA at three seminars on livestock nutrition in Mauritius, Jamaica and Antigua (see CTA Activities on page8).
Dr T R Preston CIPAV Calle 8a, No 3-124 Piso 9 Apartado Aero 7482 Cali, COLOMBIA
Alley-cropping stabilizes maize yields
A long-term trial which compared maize crops with and without alley-cropping, and alley cropping with and without fertilizer, has been undertaken in Gandajika, Zaire. Thishasshown that although alley-cropping alone maintains soil productivity, addition of moderate amounts of fertilizer is the best means of achieving stability and increased productivity for farmers in south-central Zaire.
Hedgerows of Leucaena leucocephala were planted with maize in rows four metres apart. The hedgerows were pruned at a height of 50cm at the beginning of the second maize season, and the prunings used as a mulch. In the sixth and seventh season of the trial one maize row out of five was eliminated to reduce the competition between the maize and Leucaena.
In the early seasons alley-crop ping did not benefit the maize much, because there were in sufficient prunings to make a mulch. The maize next to the hedgerows yielded poorly St researchers intensified the pruning cycle.
The results were that alley-crop ping produced a consistent crop of significantly higher yield than that which could be produced without alley-cropping. Fertilizer increased yields in both cases but was not alone sufficient to halt the decline in yield from the third season onwards in the maize which was grown without alley-cropping.
Alley-farming Network in the Tropics (AFNETA) PMB 5320 Ibadan NIGERIA
How external inputs can maintain Pacific island soil fertility
Agriculture is the main base of the economy of the South Pacific islands, and a subsistence system of mixed cropping, starchy root crops mixed with banana, breadfruit and coconut, is the mainstay. Farmers use a variety of local resources to maintain soil fertility, but external inputs can increase fertility, says Stanley Weeraratna of the University of the South Pacific.
Crop yields on newly-cleared land are high, but decline sharply after the first couple of year's cropping. Constraints on available space mean that the same land is cropped over and over again without fallowing. Mulches of dadap leaves, grass, weeds, dried coconut fronds, banana and breadfruit leaves at 30 tonnes per hectare can increase yields by up to 65%.
In atolls where organic materials are limited farmers use shredded coconut logs, wood chips and coconut husks. Poultry and pig manure is used where available.
Organic fertilizer in the form of mulch has to be applied in large quantities, and it is sometimes necessary to replenish the soil nutrients that are removed with the biomass in the form of inorganic and/or organic fertilizers as an external input. Results of studies indicate that a mixture of local and external inputs obtain the maximum benefits from local resources.
Stanley Weeraratna, School of Agriculture, University of South Pacific Alafua, WESTERN SAMOA
African water network
The Kenyan network KWAHO and the Environment Liaison Centre (ELC), also based in Nairobi, are joining to create a new network of African NGOs which will increase their involvement in projects concerned with the provision of water.
KWAHO PO Box 61470 Nairobi, KENYA
Pig production costs halved
The use of locally-available raw materials has halved the cost of pig production in the Solomon Islands.
In trials funded by the Overseas Development Administration's Geographical Divlsion, local copra meal, cassava and fishmeal were fed to pigs instead of imported cereals and soya. Fishmeal concentrate can also be added to feeds of fresh coconut and cassava, although it is still necessary to import vitamins and minerals. Such has been the demand for the local feed that a feedmill at Mamara has been brought back into operation, and now produces 40-60 tonnes per month.
Natural Resources Institute Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
Zimbabwe to phase out DDT
DDT is to be phased out of the anti-tsetse campaign in Zimbabwe: environmentalists have found traces of the chemical, and shell thinning, in the eggs of the fish eagle population of Lake Kariba.
Preliminary results of surveys, carried out by Natural Resources Institute scientists and financed by the UK Overseas Development Administration's Geographical Division, have led the Zimbabwean Government Veterinary Service to look into ways of using deltamethrin as a substitute for DDT. Like DDT, deltamethrin will be handsprayed on tree-trunks to control tsetse flies
Natural Resources Institute Central Avenue, Chatham Maritime Kent ME4 4TB, UK
Agri-waste burner will save energy
The Natural Resources Institute has designed a waste burner which could solve the problems of industries which have large amounts of agricultural or forestry waste and yet need energy.
The NRI suspension burner, which is currently undergoing field trials at a commercial rice mill in Sri Lanka, at the moment burns rice husks as fuel for a steam boiler which parboils rice. By burning up to 140kg rice husks per hour the unit generates 1900MJ/hour, equivalent to using 1055kg of wood or 523 litres of oil per day.
It is small, cheap and easy to build with locally available materials. It operates efficiently losing little energy from the furnace. The beauty of it is that it can easily be adapted to burn other particulate residues such as sawdust, coffee husks, groundnut shells or sunflower seeds.
Alan Robinson, NRI, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK
INTERNATIONAL COURSE ON VEGETABLE PRODUCTION 16 June-13 July 1991
The course aims to provide extension workers with insights and views on how to make extension an effective instrument for development. The course is open to those who act as higher or middle-level managers or trainers in governmental or non-governmental extension agencies or other development-oriented services. Women are especially invited to apply. Applications must be received before 20 March 1991.
INTERNATIONAL COURSE ON VEGETABLE PRODUCTION 5 August-8 November 1991
The course is intended for University trained specialists working in horticultural education, research and extension with emphasis on vegetable crops. Applications must be received by 23 April, 1991
The above courses are being offered by: International Agricultural Centre, PO Box 88, 6700 AB Wageningen THE NETHERLANDS
REHABILITATION AND MANAGEMENT OF IRRIGATION PROJECTS 20 May-27 July l991
Intensive applied course organised in association with international consulting engineers drawing on many years' practical experience of the rehabilitation, upgrading and management of irrigation schemes.
M A Burton, Short Course Director, Institute of Irrigation Studies, The University of Southampton SO9 5NH. UK
LIVESTOCK RESEARCH SUPPORT - MANAGEMENT OF INFORMATION FOR ANIMAL AGRICULTURE 15 July-2 August 1991
The course is for librarians, documentalists and scientists
seconded to information work. Nominations, from candidates' employers only, to
be received by 1 April 1991.
ILCA, PO Box 5689, Addis Ababa, ETHIOPIA
STUDY SEMINAR 131: BIBLIOGRAPHIC INFORMATION ON DEVELOPMENT 27 August September 1991
This course is for professional library personnel involved in
the management and development of library services. It aims to give practical
training on information systems for libraries based on micro CDS/ISIS with
demonstrations of other systems for comparative purposes. Applications as soon
as possible to:
Course Assistant, The Institute of Development Studies, University of Sussex, Brighton BN1 9RE, UK
THIRD INTERNATIONAL SYMPOSIUM ON TILAPIA IN AGRICULTURE 11-16 November 1991 at Hotel Ivoire, Abidjan
A follow up to ISTA I and II, the objectives are to promote
interaction and cooperation among Tilapia scientists and culturists through the
sharing of information and discussions on future research and development
strategies; to increase awareness of the potential for growth in the industry
worldwide and to make readily accessible the proceedings of the
The Symposium will be in English and French.
Enquiries to: ICLARM (ISTA III), MC PO Box 1501, Makati Metro Manila, THE PHILIPPINES