FEATURES

Transferring technologies for agriculturaldevelopment in the Third World

An overview of approaches followed by the agriculturelaboratory of the IAEA's Laboratories at Seibersdorf

r^ report by the World Food Council of theUnited Nations recently concluded that globalhunger and malnutrition keep deteriorating.Famine is now threatening more than 30 millionpeople with starvation as a result of natural dis-asters (mostly drought or flood) and continuingsocial and political emergencies (civil unrest andwar).

Less visible but no less tragic is the continu-ing crisis of chronic malnutrition. It affects onein five people overall and 50 of the world'spoorest countries. Almost 200 million childrenunder 5 years of age suffer from protein-energymalnutrition, and 40 000 of them die each dayfrom malnutrition causes.

Incongruously, despite the situation, there iscont inued rapid population growth in thedeveloping world. Many developing countries,especially in Africa, are no more successful incontrolling their population growth today than inthe past and the region still has a growth rate inexcess of 3% a year.

The consequences of this are all too clear:There is greater pressure on land resources;

fa l low periods are shorter; overstockedgrasslands are becoming exhausted; forests arebeing eaten away by expanding croplands andincreased gathering of fuelwood; the ecologicalbalance is being disrupted: soils are beingdegraded and water sources are drying up orbecoming polluted; yields are being reduced;incomes are falling and unemployment rising;and the desert and poverty are taking over thecountryside.

As a result, the "food gap" between domesticsupplies and the fast-growing demand is widen-ing inextricably. Although international aid hasmitigated the consequences of this, it is obvious-ly not a viable solution. Today, it only serves as

Dr Richards is Head of the Agriculture Laboratory of theIAEA 's Laboratories at Seibersdorf. Interested readers shouldcontact the author for references and further information.

a derisory palliative and is likely to lead only toa population which is permanently dependent onhandouts.

To make things worse, the least developedcountries, and others having both low incomesand food-deficits, have seen their share of foodaid steadily decline over the last 2 to 3 years.This is because industrialized countries that aremajor food donors are re-directing their static ordepressed food aid programmes to EasternEurope and the former USSR at the expense ofthose to the Third World.

To fill the gap in basic food supplies, it hasbeen calculated that in Africa, food productionwill have to increase to more than twice theaverage growth rate of 1.7% per annum achievedover the last 10 years. Given the difficulty ofachieving this new target, experts conclude thatthe food situation in Sub-Saharan Africa can beexpected to worsen as the decade progresses andthat most of the countries in the region are likelyto be food-deficient by the year 2000.

by J.I. Richards

To fill persistent "foodgaps" in manycountries, agriculturalproduction mustincrease dramatically.(Credit: M. Lutzky, FAO)

IAEA BULLETIN, 4/1992

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10

In its bid to address this depressing situation,the United Nations General Assembly in Decem-ber 1990 adopted an "International DevelopmentStrategy". Its purpose is to alleviate hunger andpoverty through the promotion of humanresource development. Likewise, the UN Con-ference on Environment and Development inJune 1992 declared that "States should cooperateto strengthen endogenous capacity-building forsustainable development by improving scientificunderstanding through exchanges of scientificand technological knowledge, and by enhancingthe development, adaptation, diffusion, andtransfer of technologies, including new and in-novative technologies".

At the IAEA, one of the three major objec-tives of the medium-term plan (1993-98) is the"enhancement of the transfer of nuclear technol-ogy and know-how to developing countries".For its part, the Joint FAO/IAEA Division ofNuclear Techniques in Food and Agriculture al-ready is managing more than 500 research con-tracts and providing technical supervision of theIAEA's technology-transfer activities in 250agriculture projects supported by the Depart-ment of Technical Co-operation. Through theseavenues, the competence of research scientists indeveloping countries is being improved so thatthey are better able to identify and resolve theproblems affecting agricultural productivity.

The Agriculture Laboratory of the IAEA'sSeibersdorf Laboratories works with the JointDivision in this endeavour. Its areas of special-ization are: soil fertility, irrigation and cropproduction; plant mutation breeding; pesticideanalysis and formulation; insect and pest control;and animal production and disease diagnosis.

The Agriculture Laboratory has a staff ofmore than 70 highly qualified and experiencedinternational personnel and a regular annualbudget in excess of US $4 million. It does notpretend to have the facilities or staff to competewith national or international laboratories, how-ever, and its work should not be confused withthat of a research laboratory. Rather, its mandateis a distinct one in the UN system: to providethree basic services to counterparts in develop-ing countries in an effort to ensure effectivetransfer of appropriate nuclear and related tech-nologies for agricultural research. These servicesaddress research and development, training, andtechnical support.

Key elements of R&D services

Four major elements are involved in theLaboratory's provision of services in the area ofresearch and development:

IAEA BULLETIN, 4/1992

• Definition of problems for which technol-ogy is required. The type and scale of problemsin any given country are important to defineclearly before appropriate technologies can beidentified or developed. In IAEA-supportedagricultural projects, there is close collaborationwith scientific counterparts in developingcountries and with the Joint FAO/IAEADivision's technical and project officers, whohave first-hand knowledge of the country and theagricultural problems being investigated. Theyalso are familiar with the technical competenceof the staff for whom the technologies are re-quired, the local physical infrastructure(laboratories, quality of electrical and water sup-plies, availability of power and air conditioning),instrument repair/maintenance facilities, andlocal environmental factors (climate, dust,thunderstorms, etc.).

This background information has enabled theAgriculture Laboratory to focus its attention onassisting counterpart scientists address well-focused research topics in five areas:

Soil science: maximizing the use of atmos-pheric nitrogen in crops and trees through plantselection and optimal plant-bacteria conditions;and optimizing the use of nitrogenous and phos-phatic fertilizers and water for maximumproductivity and profit while minimizing theirnegative impact on the environment. (See box onpage 13.)

Plant breeding: the creation of crop varietieswith improved productivity characteristics andenhanced resistance/tolerance to diseases. (Seerelated article beginning on page 25.)

Agrochemicals: development of new pes-ticide formulations which are target-specific andlong acting with minimum impact on the en-vironment. (See box on page 12.)

Entomology: reduction in the indiscriminateuse of insecticides for controlling agriculturallyimportant insect pests through the developmentand promotion of an environmentally-friendlytarget-specific system, the sterile insect techni-que (SIT). (See box on page 16.)

Animal production: improvement of live-stock productivity by proposing alternativemanagement strategies in animal feeding andbreeding; and definition of the incidence andprevalence of major livestock diseases andmonitoring the efficacy of vaccination or othercampaigns for disease control/eradication. (Seearticle beginning on page 34.)

• Identification, modification, and stand-ardization of appropriate technology. TheLaboratory's procedure for identifying appro-priate technologies conform to a number of inter-national guidelines formulated recently: (1) useshould be made of transparent, user-friendly

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technologies to promote sustainable agriculturaldevelopment; and (2) the IAEA should promoteonly those nuclear technologies which have aclear advantage in developing countries overother technologies.

With these guidelines, existing availabletechnology (equipment, methodology, chemi-cals, biologicals) can be identified, and modifiedif required, and subsequently standardized toconform to international or IAEA norms.

• Development and standardization of"custom-made" technology. All too often, ap-propriate technology does not exist "on theshelf and has to be "custom-made" or dev-eloped. This is achieved in a number of ways.One is through active collaboration with nation-al, international, or commercial laboratories ororganizations, whereby certain portions or thewhole technology development (biologicals,equipment, methodologies) are contracted out.The Agriculture Laboratory currently liaiseswith more than 40 such groups worldwide. Thesecond way is through the development of ap-propriate technology by and between scientistsin the Agriculture Laboratory working withscientists from other disciplines, such as those inthe chemistry and physics laboratories, and withskilled staff in the mechanical and instrumenta-tion workshops. In both cases, the technologyhas to conform to international or IAEA norms.

Examples of technologies undergoing R&Dat the Laboratory include:

Soil science: methodologies (DNA probes,GUS-gene and other molecular biology techni-ques) for investigating the ecology of nitrogenfixing microbes in pasture and grain legumes;development of optimal emission- and mass-spectrometers for nitrogen-15 and carbon-13analysis to identify plant genotypes with supe-rior nutrient uptake/utilization traits.

Plant breeding: mutation breeding techni-ques using ionizing radiation (gamma radiationand fast neutrons) and chemical mutagens forinducing genetic variation and providing in-creased opportunity for selecting plants with im-proved productive traits; in-vitro propagationtechniques to facilitate the production of largenumbers of treated plants and speed up thegenetic confirmation and agronomic evaluationof new genotypes (plantains, bananas, cassava,yam, etc.).

Agrochemicals: slow (controlled) releaseformulations of herbicides in aquatic systems;development of pesticide impregnated screensfor tsetse fly control; formulation and testing ofeffective pesticides and attractant "cocktails"against the screwworm fly under simulated en-vironmental conditions; development of analyti-cal methods for pesticides and their residues.

Entomology: the SIT (mass rearing, ship-ment, and release of insects) for the con-trol/eradication of tsetse fly and Mediterraneanfruit fly; advanced technologies in genetics andmolecular biology, insect nutrition, and dieteticsto make SIT applicable to more insect pests inlarger areas at lower cost.

Animal production: kit technologies for themeasurement of reproductive and metabolic hor-mones in livestock through radioimmunoassay;measurement of nutritional metabolites that limitthe productivity of farm animals using colori-metric techniques; diagnosis of infectious dis-eases in livestock using enzyme-linked im-munosorbent assays (ELISA).

• Validation and field testing. Before anytechnology is distributed to counterparts inIAEA-supported projects, it is checked andvalidated by selected field laboratories. They areasked to use the new technology (or where ap-propriate compare it with an existing technol-ogy) and complete comprehensive question-naires on its performance (sensitivity, accuracy,relevance of generated data), robustness, user-friendliness, and other factors. Based on theirresponses, the technology is then furthermodified and eventually enters the pool of"green light" technologies to be promoted foruse by scientists in developing countries.

A much forgotten aspect of field testing—and subsequently of technology transfer—re-lates to the physical distribution of new tech-nologies. Some might be sent only once, butmore commonly, the technologies are shippedon a regular basis. This entails satisfying both thenecessary "in-house" bureaucratic route, and theoften problematic, time-consuming, and con-stantly changing international airline and sea-freight regulations governing packaging andpacking materials, radioactive materials, importregulations, and customs clearance proceduresof national governments. Whereas the IAEA'sappropriate offices assist in this task, theAgriculture Laboratory is responsible for ensur-ing rapid, safe, and legal delivery of technologiesthat it develops.

Forms of scientific training

Clearly there is little point in providing tech-nologies that people are not trained to use cor-rectly. Recipients must know how to use, handle,and maintain these new technologies, and how toassess the quality of their operation and to inter-pret the data they generate. Training of scientistsand technical support staff thus constitutes onemajor component (and some believe the mainone) of technology transfer.

IAEA BULLETIN, 4/1992 11

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Agrochemicals:Improved

formulations

>——-a

1)a

conventional formulation

» ' ' ' .v

', toxic level for fishiiiiiui minium ini i in ii ii inn minimi i in ii nun mi i in MI i mi ii i nunf *

'• controlled-release formulation

Time

Weeds are undesirable plants that grow in almostall cultivated crops. They compete with cultivated plantsfor nutrients, light, water, and space and reduce the yieldof the crop and producivity of the land. In order toincrease crop yields farmers control weeds by pulling

A scientist at the them out bV hand, machine, or by applying herbicides.IAEA's Seibersdorf However when a herbicide (like other pesticides) is

Laboratories applied to a crop, a lot of it is lost during and soon afterpreparing a application. During application some herbicide is carried

controlled-release away from the target area by wind; some herbicideformulation of deposited on soil or plants is washed away by rain; and

herbicides. some is broken down by the action of light and oxygen

in the environment. Thus, only a fraction of the appliedherbicide is left to protect the crop.

In anticipation of these losses, high doses areapplied to ensure adequate herbicidal activity. However,the initial high dose can harm non-target species suchas fish, birds, and other animals. Also, since the her-bicide is subject to degradation due to environmentaleffects, it does not last long and repeated applicationsbecome necessary.

These problems can be overcome by using control-led-release formulations in which the herbicide istrapped in an inert matrix and is released in quantitiesslightly in excess of minimum effective herbicide levels.This prevents the loss of the herbicide from the actionof water, light, and other environmental effects, thusmaking it active for a longer period of time. The durationof the effect of pesticides can be controlled by properselection of the inert matrix and design of the formula-tion.

Several controlled-release formulations of her-bicides have been prepared at the IAEA's SeibersdorfLaboratories. Some of these have contained herbicidelabelled with a radioactive isotope in order to study therate of release of the herbicide from the formulations.Based on this information, a few formulations wereselected for biological tests in the greenhouse and inseveral collaborating countries. The herbicidal efficacyand environmental safety of controlled-release andcommercial formulations were conducted in rice crops,as well as in rice-fish and rice-shrimp mixed ecosys-tems. The tests indicated that these formulations con-trolled weeds more efficiently and were less phytotoxicto rice plants than the commercial formulations. Similar-ly, tests carried out on Azol/a, a water fern found exten-sively in Southeast Asia in mixed culture with rice plants,showed that the application of controlled-release her-bicides effectively controlled weed growth but had rela-tively little toxic effect on Azolla compared with commer-cial herbicide formulations. — contributed by Dr Man-zoor Hussain, Head of the Agriculture Laboratory'sAgrochemicals Unit.

12 IAEA BULLETIN. 4/1992

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Soil science:Focus on grainlegumes

Analysing plantsamples at theSeibersdorfLaboratories SoilScience Unit.

Grain legumes such as common bean, soybean,pea, cowpea, and groundnut are among the world'smost important crops, and a particular focus ot work inthe Soil Science Unit of the Agriculture Laboratory.

The crops are particularly nutritious—rich in protein,minerals and vitamins—and they make up a largeproportion of the human diet. Other species such asforage legumes (alfalfa, clover etc.) and tree legumes(including Leucaena, Gliricidia. Acacia, and Mimosa)play a highly significant role in sustainable livestockpractices of peasant farmers in the developing world.Leguminous crops, with the help of root nodulatingRhizobium bacteria, are able to derive nitrogen from theatmosphere in order to build-up tissue protein. Thisprocess, called biological nitrogen fixation, is able tosupply nitrogen for plant growth, thus reducing the needfor nitrogen fertilizer and its associated energy costs.Some of this nitrogen remains in the soil after croppingand enhances soil fertility. Nitrogen fixation may as-sume greater importance in future efforts to reduceexcessive use of nitrogen fertilizer and associated en-vironmental pollution of groundwater with nitrates andof the atmosphere with nitrogen oxides.

Not all legumes or rhizobial bacteria are equallyefficient in fixing atmospheric nitrogen. The nitrogen-15isotope technique has been found to be the most reli-able method to quantify biological nitrogen fixationunder greenhouse and field conditions. Largelydeveloped at the Agriculture Laboratory at Seibersdorf,the technique has now been transferred to mostdeveloping countries. It is being used in a number ofFAO/IAEA technical projects to enhance biologicalnitrogen fixation, saving nitrogen fertilizer and largeamounts of foreign exchange.

Current research is focusing on the improvement ofboth yield and nitrogen fixation in grain legumes througha multidisciplinary research approach. Also, studies arebeing pursued on measuring the nitrogen fixationcapabilities of some nitrogen fixing tree species com-monly used in agroforestry systems and on factorswhich influence the amount of nitrogen fixed, for restora-

tion/maintenance of soil fertility, soil conservation, andfuelwood production.

In support of the more than 100 research contrac-tors participating in the FAO/IAEA international andregional networks, the Soil Science Unit analyses some15 000 samples every year mainly for nitrogen isotoperatio. Analytical services are also provided to developingMember States in receiving IAEA technical assistancebut lacking appropriate analytical facilities. The Unitplays a leading role in the development of new isotopicmeasurement techniques and equipment and therefinement of those in use for routine purposes.

In the next biennium, it is also planned to provideMember States with quality assurance services; this willgive scientists confidence to regularly employ trans-ferred technology and provide an international seal ofapproval to scientific data and associated conclusionsgenerated by the nitrogen-15 technology.—contributedby Dr Felipe Zapata, Head of the AgricultureLaboratory's Soil Science Unit.

Percentage ofnitrogen derivedfrom theatmosphere bycommon beancultivars

80

GO

ciD>

2 40

20

Cultivars having lowest fixation

Cultivars having highest fixation

Austria Chile Colombia Guatemala Mexico

cultivars

Peru

IAEA BULLETIN, 4/1992 13

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Scientific training at the Agriculture Laboratory in Seibersdorf,1985-92

Fellowship training

Total No. of fellows: 262

13

17°:

25°,:

Interregional training course

Total: 411 participants in 21 courses

1 7 30%I Africa

] Asia

I Latin America

| Middle EastI & Europe

25°/< 28';

Scientific visits

Total No: 6912

28%

16%

44%

Scientific training activities in agriculture

The Agriculture Laboratory is a focal point of scientific training under IAEAprojects and programmes.

Overall, three types of training related to the application of nuclear andrelated techniques in agriculture are offered to suitably qualified applicantsfrom the IAEA's Member States. These are:

• Fellowship Training ("hands-on" training for junior scientists and tech-nical support staff):

• Training Courses ("awareness" training for junior scientists):• Scientific Visits ("awareness" training for senior scientists).Over the past 7 years, more than 700 scientists from developing countries

have participated in these IAEA training programmes for agricultural develop-ment. — contributed by Ms. M.E. Ruhm. Training Officer, IAEA SeibersdorfLaboratories.

Each year, the Seibersdorf Laboratories trainabout 13% of all trainees supported under IAEAtechnical co-operation projects. (See box andgraphs.) In general, two forms of training are

followed, each catering to the needs of seniorand junior scientists, as well as technical supportstaff:

• Techniques training. The AgricultureLaboratory provides "hands-on" training inspecific technologies. Training lasts between 2to 6 months depending on the complexity of thetechnology and the calibre of the trainee. Train-ing is sharply focused, with supervision providedby a Laboratory scientist and guidance by theproject's technical officer. Other competenttraining locations can rarely provide the traineewith such specific, project-related training, andthe trainee tends to "fit in" with the normal re-search work of the laboratory.

• Research and "awareness" training. TheAgriculture Laboratory also trains scientists inbasic and applied aspects of research. Althoughscientists from countries with well-developed re-search infrastructures are seldom taught how toconduct research, they normally have a scientificresearch supervisor to guide them or to emulate.This is not the case in many deve lopingcountries. Consequently, there is a need to pro-vide these scientists with training in definition ofa research problem: experimental planning:sample numbers and sampling frequency: dataanalysis and interpretation; and publication ofresults and conclusions. Where appropriate, thistraining follows aspects of the Laboratory's"techniques training". It normally lasts 6 to 12months, and involves the trainee in a reseachproject which is directly related to one beingsupported by the IAEA in their countries.

"Awareness" training is conducted in twoways. One is through interregional training cour-ses, two to four of which are hosted by theAgriculture Laboratory each year. The courseslast 5 to 8 weeks and are ideally suited for youngprofessional scientists who need familiarizationwith the technologies currently available and thepresent state of knowledge in a specific field ofagriculture. Selection is normally very keen forthe 16 to 20 course placements, and about 80r/fof applicants have to be turned away from eachcourse.

The second extremely important form of"awareness" training is for senior professionalscientists who visit Seibersdorf for up to 1 weekto become familiar with new developments innuclear and related technologies, to catch up onscientific literature often not available in theirhome countries, and to discuss new scientificdirections with research personnel. Such visitsalso often lead to collaborative links betweenSeibersdorf and developing country laboratories.This in turn leads to more rapid scientificd e v e l o p m e n t and p romot ion of g rea te rfriendship and understanding.

14 IAEA BULLETIN. 4/1992

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Support services and feedback

At this stage of the technology-transferprocess, one assumes that the technology is inplace and that staff have received basic training.What more, one might ask, can be done to assist?Unfortunately, a number of problems invariablyoccur at this stage with the equipment ormethodology. At the same time, a great deal ofpressure is put on project participants by both theIAEA and local employer to demonstrate results.

Therefore, this is an extremely critical step inthe technology-transfer process. Scientificcounterparts must be given the assurance that theIAEA will provide appropriate guidance andsupport in the use of the newly transferred tech-nology so that they can proceed with the projectplan with confidence.

The Agriculture Laboratory provides twoservices which may help provide this con-fidence:

• Analytical support and quality assurance.Through its analytical support services, theLaboratory undertakes analyses of sampleswhen the transferred technology is temporarilynon-operational. In this way, interruptions arealleviated and the scarce funds invested in oftenvery expensive agricultural projects are not lost.

• Quality assurance. The second service,that of providing quality assurance, arguably hasbeen the most neglected aspect of the Agricul-ture Laboratory's support until recently. Themajor components of quality assurance are theprovision of guidance or chemical/biologicalmaterials which enable scientific counterparts inthe project to have confidence in the equipment,analytical procedures (quantitative and qualita-tive), and data generated by the transferred tech-nology.

Ideally, this degree of confidence shouldconform to international standards and thusallow the data to be used for defining acceptanceof an agricultural product for international trade;submission to editors for publication in interna-tional agricultural research journals; and estab-lishing the laboratory as a national referencelaboratory for the analysis in question. Thematerials provided include international refer-ence materials, external quality assurancepanels, standardized protocols on methods, andguidance on how counterparts should make andassess internal quality assurance parameters.The recipient is required to participate in exter-nal quality assurance initiatives; laboratorieswhose data do not fall within specified limits areinformed and advised as to ways of improvingtheir use of the technology. The AgricultureLaboratory is now addressing the whole issue ofquality assurance with vigour in many areas of

its support services. The effort is designed toimprove the implementation of field projects.

Reporting and application. The Laboratorycan only improve its services if it receives com-ments (both negative and positive) from its end-users either directly or through project technicalofficers. No successful transfer of technologylaboratory is an island.

Whereas some believe that no correspon-dence from counterparts generally indicatessatisfaction with the technology, it may not bethe case that "no news is good news". For itspart, the Agriculture Laboratory frequently ap-peals for feedback through various avenues, in-cluding articles such as this one.

Impact of technology transfer

In a number of areas, transferred nuclear andrelated technologies have had a major impact onagricultural development in Third Worldcountries.

In soil science, for example, technologies formeasuring nitrogen-15 have enabled scientists todevelop optimal fertilizer practices for improvedcrop productivity in difficult agroecological sys-tems.

In plant breeding, irradiation procedures forinducing plant mutations have contributed to therelease of more than 1500 new crop varietiesworldwide. Radioisotopic methods have beenused in developing improved and environmen-tally stable formulations of insecticides (del-tamethrin) against tsetse flies and of controlledrelease herbicides (e.g. butachlor) for controllingweeds in rice-fish ecosystems.

In entomology, apart from the employmentof the sterile insect technique in the eradicationof the New World Screwworm from NorthAfrica, SIT has been successfully used to eradi-cate the Medfly from Mexico and the Melon Flyfrom Japan.

In areas of animal health, ELISA technologyused for the seromonitoring of livestock vac-cinated against rinderpest has contributed to thefact that no major outbreak of this disease hasbeen reported in Africa recently.

Improving the programmes

In light of such successes, the IAEA is aboutto conduct a review of its traditional means andprocedures for technology transfer in order toensure that more programmes achieve highlevels of quality. It already has singled out thedevelopment of human resources, quality controlservices, and the maintenance of nuclear in-

IAEA BULLETIN, 4/1992 15

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strumentation for more attention in this newstrategy. Addit ional ly , the Agency might con-sider taking a broader, more integrated approachto project design as a way to promote a moreinterdiscipl inary approach to identifying andr e s o l v i n g problems a f f ec t ing a g r i c u l t u r a lproduction.

In his address to a recent regional Conferencefor Africa, the Director General of the Food andAgriculture Organization appealed for greaterunders tanding. "We automatically gauge oursolidarity towards a particular country accordingto its conformity to our values." he stated. "Yet Iwould humbly and earnestly request that care,flexibility, and delicacy be used in such an ap-proach to Africa."

Far too often, bilateral and international or-ganizations have been too arrogant in promotinga "we know what is best for you" approachbefore they t ru ly address the values that the

recipients place on such in i t i a t i ve s . S imi lar ly ,prestige programmes often have been conductedthat give kudos to national governments or sup-port organizations rather than addressing the trueneeds of the people.

Clearly there must be greater emphasis ondialogue with countries before programmes areimplemented. This should involve mul t id isc ipl i -nary yet integrated teams that assess the va lueand impact of programmes on ag r i cu l tu ra lproduction and productivity, the country, and itspopulation.

This wi l l require far greater collaborationamong UN and other organizations so that aconcerted effort can be made by the internationalcommunity to resolve the huge problems ofhunger, ma lnu t r i t ion , and poverty facing thedeveloping world. "1

Entomology:The SIT andcontrolling

insect pests

Standard laboratory testto assess the mating

competitiveness ofsexually sterile tsetse fly

males in relation tofertile males.

The primary research and development (R&D)activities of the Agriculture Laboratory's EntomologyUnit are to make the sterile insect technique morereliable, efficient, and applicable for the control ofinsect pests in developing countries.

The technique, first tested less than 40 yearsago, has revolutionized insect control and has madepossible the total eradication of pest insects fromlarge areas when used in conjunction with othermethods in an integrated pest management ap-proach. It is an environmentally friendly means ofcontrol. Its effects are so target specific that no otherliving organisms in the treatment area are affected.

While simple in technical concept (i.e., the massrearing and release of sexually sterilized males thatmate with and thereby render the wild females infer-tile) the SIT requires a complex operational or-ganization including continual R&D back-up sup-port. The Entomology Unit has provided such sup-port to past eradication programmes organized bythe Agency for the Mediterranean fruit fly in Mexicoand Central America and the tsetse fly and screw-worm in Africa.

Tsetse flies, for example, have a low reproduc-tive capacity. Relatively few sterile insects need tobe released into the pest insect habitat to outnumbernative fertile males. The Unit provides considerablenumbers of tsetse fly pupae to IAEA projects in Africaand to collaborating scientists in IAEA MemberStates.

For the Mediterranean fruit fly, many hundredsof millions of highly viable insects must be producedfor release each week. Costs have been reduced bydesigning equipment and developing diets that uselocally available labour and materials. Recentlygeneticists in the Unit have developed strains of thefruit fly with lethal traits in the females that can betriggered by temperature. Since the sterile male isthe active ingredient in a SIT programme, thefemales are unnecessary or even unwanted.Elimination of females in the embryo stage can saveup to 40% of the rearing and release expenses. Thereleased sterile female will still try to lay eggs and asa result damages fruit. Furthermore her presencedetracts the sterile males from seeking wild femaleswith which to mate.

Further development efforts have resulted innew genetic sexing (GS) strains of the fruit fly thatare much more genetically stable than the originalones. Because of their extreme temperature sen-sitivity, which also affects the developmental stagesafter the embryo, special handling procedures havehad to be developed to ensure consistent and reli-able colony production. Behavioural studies in largecages and also with flies released in the field haveshown that the newest GS strains are not only verystable, but they survive and behave as normal wildflies do under natural conditions: these charac-teristics are essential for the success of SIT pestcontrol programmes. — contributed by Dr R.Gingrich. Head of the Agriculture Laboratory s En-tomology Unit. See the following article lor a reporton the successful use of the SIT in North Africa.

16 IAEA BULLETIN. 4/1992