2.1.1 Introduction
2.1.2. Evolution
2.1.3. Achievements and Impacts
2.1.4 CCERs and other External Reviews
2.1.5 Emerging Challenges and Future Strategies
CIMMYT serves as a world centre for the improvement of bread wheat, durum wheat and triticale, and, jointly with ICARDA, for barley in Latin America. It also acts as a repository for a significant proportion of the world's publicly available genetic resources of bread wheat and triticale. The programme has 31 international scientists; 19 are located in Mexico. Programme expenditure in 1997 was US$ 8.585 million.
A large proportion of the Wheat Programme staff and budget (currently about 50%) is devoted to the development of improved germplasm. Much of the rest (currently a further 26%) is devoted to disciplines directly supporting crop improvement, notably plant protection, cereal chemistry, crop physiology, biometry, and genetic resources. Most breeding resources are invested in spring bread wheat with much of the rest going to winter bread wheat and durum. Very limited resources are currently devoted to triticale (<6%) and barley (<5%). Only five out of 31 international scientist positions in the programme focus on production systems research and management.
This section of the report briefly reviews the Wheat Programme: its evolution, achievements and impacts; emerging issues; and future directions.
Background and Target Areas
Wheat and rice are the world's most important food crops. Global production of wheat is now approaching 600 million t, with international trade approximately 100 million t annually. Up until recently, both global production and international trade in wheat have broadly kept pace with growth in the human population. However, in recent years there has been a slowdown in the growth of global wheat production relative to the growth in human population. As a consequence, global reserves of wheat have fallen to disturbingly low levels.
Given the critical role of wheat as a food crop, because of its wide adaptability and flexibility in end uses, it is important that the balance between global production growth and human population growth be restored. World wheat demand is conservatively estimated to increase by 40% by 2020. This will have to come predominantly from productivity increases rather than area expansion with some notable exceptions such as the Cerrados of Brazil.
Wheat is grown in a very diverse range of environments. CIMMYT recognizes 12 global mega-environments (MEs), nine of which, ranging in area from 3 million to 36 million ha, are of importance in the developing world. CIMMYT uses the concept of the MEs to develop targeted germplasm to specific environments and particular biotic and abiotic problems.
CIMMYT has been involved in bread and durum wheat breeding since its establishment in 1966. The early breeding efforts focused on the introgression of dwarfing and photoperiod insensitive genes into high yielding, disease resistant (particularly stem, leaf, and yellow rust) backgrounds. Significant emphasis was given to breeding for irrigated sub-tropical environments (effectively ME1), which were the initial sites for the Green Revolution. The focus has gradually broadened to include all nine (9) MEs of importance in developing countries, although some of the larger ones, notably ME1 and ME2 for spring wheat, ME7 and ME8 for facultative wheat and ME10 and ME11 for winter wheats, receive greater attention.
When first established, the CIMMYT wheat breeding programme incorporated a number of innovative features, including:
i) rapid generation turnover and two (2) cycles of selection/year using shuttle breeding between Toluca and the Obregon field stations;ii) effective exploitation of a very wide range of germplasm such as spring x winter wheats;
iii) a heavy emphasis on multidisciplinary teamwork involving breeders, pathologists, cereal chemists, biometricians, physiologists, and agronomists;
iv) free sharing and exchange of germplasm and information. In particular, the international nursery system provided an excellent mechanism for interaction with NARS collaborators and outreach staff and permitted the rapid identification of outstanding lines both from CIMMYT and NARS and their early recycling with the crossing programme; and
v) substantial (unrestricted) budget support which permitted large numbers of crosses, segregating populations, screening tests, yield assessments, and the advantages of scale. This has allowed expansion of the programme from about 500 crosses in the 1970s to more than 5,000 now.
Based on these innovations, the CIMMYT Programme has been highly successful. The Wheat Programme has provided a continuous stream of outstanding germplasm to NARS which has dramatically changed wheat production in the developing world. In the light of this success, the broad goals and much of the methodology of the CIMMYT Wheat Breeding Programme have been maintained relatively unchanged over the years. This is not to say that significant modifications and improvements have not been made. For example, the breeding methodology changed in 1985 from a pure pedigree system to a pedigree bulk system. Further, the breeding objectives were expanded to cover a wider range of traits of interest to NARS including:
· durable resistance to leaf and stripe rust;
· resistance to head scab;
· greater adaptation to marginal environments; and
· acid soil tolerance.
However, the broad thrust of the programme has remained unchanged for the past three decades.
After 1989, CIMMYT, in common with many other centres in the CGIAR System, suffered notable funding cuts. These funding cuts reached their peak about 1994 and caused a serious re-evaluation of the programme's priorities. Since then CIMMYT's funding has improved, principally due to an increase in restricted funding, which now accounts for about 50% of CIMMYT's budget. However, the staffing levels in the Wheat Programme have continued to decline from 42 in 1994 (34 senior staff, five associate scientists and three post-doctoral fellows) to 37 in 1997 (31 senior staff, four associate scientists and two post-doctoral fellows).
With respect to barley, CIMMYT has been involved in breeding since 1973. As in wheat, the initial emphasis was on the development of agronomically superior cultivars with high yield potential and multiple disease resistance. In 1984, a joint programme agreement was negotiated with ICARDA. Over time the focus of the programme has broadened to include all production regions of Latin America and all end uses, although the primary focus remains on food and feed rather than on malt. The CIMMYT Wheat Programme funds the operating costs of the joint ICARDA/CIMMYT Latin America Region Barley Breeding project. The operational support for the programme has remained at the same level since 1984; however, visiting scientist and post-doctoral support for the programme has been withdrawn due to downsizing in the Wheat Programme.
From 1998, CIMMYT will adopt a new set of 21 integrated multidisciplinary projects aimed at improving the integration and efficiency of CIMMYT's activities. Wheat Programme staff are involved in 16 of these new projects (six global, four regional, five frontier, one special focus) and the Wheat Programme carries prime responsibility for the management of six projects.
(a) Global Impact on Sustainable Wheat Production
The CIMMYT Wheat Programme has had a very significant global impact on sustainable wheat production. Detailed quantitative assessments indicate:
i) By the early 1990s, over 80% of the wheat varieties being released by CIMMYT's national programme partners were derived at least in part from CIMMYT germplasm. This level of output has continued through the 1990s. In the last few years, for example, more than 160 bread wheat, durum wheat, triticale, and barley varieties related to CIMMYT Wheat Programme germplasm have been released by more than 30 countries.ii) In the early 1990s, over 45 million ha in developing countries were planted to CIMMYT-related wheat varieties each year, accounting for about 70% of total wheat production. The most recent estimates indicate that the area planted to CIMMYT-based bread wheats has risen to 55 million ha, accounting for nearly 80% of total production.
iii) In 1990, a conservative estimate by the Centre of the extra grain produced per hectare due to the use of improved CIMMYT-related varieties (on average taken to be 200 kg/ha/crop) was 9 million t on an annual basis in developing countries, worth over US$ 1.5 billion. The most recent estimates suggest current gains stand at an extra 11 million t of grain worth over US$ 2.0 billion annually (in 1990 dollars).
In addition, the strong resistance of CIMMYT cultivars to a number of previously serious diseases and pests, particularly stem and leaf rust, means that additional developing country farmers have gained considerable indirect benefits through:
i) the need to use significantly lower inputs of costly and sometimes dangerous agrochemicals to control diseases; andii) the capacity to shift resources previously committed to pesticides to other inputs (fertilizer, water) and to alternate practices that improve the sustainability of their farming systems.
Other notable achievements include:
· the identification of exciting new sources of resistance to a wide range of pests and diseases of bread wheat, durum wheat, triticale, and barley, including yellow rust, Karnal bunt, fusarium head scab, Russian wheat aphid and Septoria tritici blotch;· the development and release of the International Wheat Information System (IWIS), which is available on CD-Rom. IWIS is a user-focused data management system that integrates many kinds of passport and performance information pertaining to nearly 1.5 million genotypes of bread wheat durum wheat and triticale. To date more than 500 IWIS compact disks have been distributed to about 50 countries, giving NARS scientists direct access to all CIMMYT pedigrees and related data for the first time;
· the development of permanent bed, conservation tillage wheat farming practices (FIRBS- Furrow Irrigation and Raised Bed Systems) which allows substantial reduction in costs (estimated to be 30%) in wheat production without significantly decreasing productivity/ha. FIRBS achieves this cost reduction because inputs (water and N) are substantially reduced and weeds are mechanically controlled reducing herbicide use. This system is being widely adopted in the Yaqui Valley in Mexico and is being adapted for use in the Punjab in India. FIRBS has the potential for adoption over much of the Ml mega-environment, a wheat production area of 36 million ha; and
· continuous active participation in training. Over the past four years, the Wheat Programme has hosted 60 trainees in Mexico for its improvement and industrial quality courses. A further 59 national programme scientists participated in the programme's wheat agronomy course, which was devolved to Pergamino, Argentina, in the early 1990s. In addition, since 1993 the programme has engaged in short-term collaboration research efforts with nearly 250 visiting scientists from national programmes.
(b) Scientific Contributions
The Wheat Programme has a diverse and talented staff with expertise in genetics, plant breeding, genetic resources conservation, plant pathology, agronomy, and crop and plant physiology. The quality of science produced by the group is good as evidenced by the number of publications in refereed international journals. This has increased substantially in recent years in response to the greater emphasis by CIMMYT on upstream research as recommended by the 1988 EPMR.
One area of particular note has been the identification and documentation by the Crop Protection and Epidemiology Group of sources of adult plant resistances to leaf and stripe rust and their genetic analysis. This is long-needed original work with profound implications for the development of durable resistance to these diseases in both bread and durum wheats. It has also opened up significant new opportunities for basic research into the mechanisms underlying adult plant resistances to rust in wheat. A second is the use of wild relatives to expand the range of genetic diversity in the Wheat Breeding Programme via wide crossing. This is a long-standing project and CIMMYT's efforts in the area have been at the forefront of the field for well over a decade.
While there are many other examples, these serve to emphasize the quality of scientific outputs from the CIMMYT Wheat Programme.
The Panel had for its consideration the reports of two external reviews of sub-programmes of the Wheat Programme conducted since the 1993 IER. The first was a review of the Wheat Crop Protection Sub-programme conducted in September 1993. The CCER made 20 recommendations in areas as diverse as staff evaluation, training, interactions with other programmes and sub-programmes, refereed publications, and research priorities. Two, however, stand out. The first related to the need for resistance diversification and gene deployment to reduce the risk of major disease epidemics, and the second to CIMMYT's lack of capacity to undertake adequate yellow or stripe rust virulence analyses. Both issues are relevant today and the need for action more pressing.
The second CCER reviewed the Wheat Germplasm Improvement Sub-programme in March 1994. This review made 15 recommendations, again covering a diverse range of subjects, including programme structure and management, training, crop priorities, interaction with NARS, hybrid wheat, and industrial quality. CIMMYT has effectively dealt with many of the issues identified by the CCER. However, several, including yellow or stripe rust resistance, industrial quality, interaction with NARS, and collaboration with the Applied Biotechnology Centre, remain current and are revisited below.
Overall, the CCER reports were helpful in evaluating the progress of CIMMYT in responding to externally identified issues. However, the strict terms of reference (ToR) in relation to the subject matter of the reviews often limited they utility. Indeed, the CCER on the Wheat Germplasm Improvement Sub-programme noted that the Panel was charged with the review of the Wheat Genetic Improvement Sub-programme. We understand that the present programme structure dictated the bounds of this review, but we also believe that genetic improvement in wheat cannot be divorced from crop protection, or agronomy/physiology, or genetic resources. We recommend, therefore, that future internally managed external reviews of the Wheat Programme be charged with reviewing all aspects of the Programme.
The point to be made is that if the CCERs have a very narrow focus, then many of the broader and generally more significant issues facing CIMMYT are outside the ToR of the reviews.
Overall, the Wheat Programme has been an outstanding success for CIMMYT over many years. The continued output of high-yielding germplasm could not be achieved without the dedicated application of good science in an output-orientated programme.
Nevertheless, despite the outstanding achievements and readily demonstrable impacts of the CIMMYT Wheat Programme, based as it has been on the paradigm established by Dr. N.E. Borlaug, it is clear it will face significant challenges in the immediate future. These challenges will arise from a variety of internal and external factors. Among the most important of these are CIMMYT's success; the accelerating push towards sustainable, pesticide-free agricultural production systems; the rapid advances in new biotechnologies and molecular genetics; the continuing evolution in CGIAR away from core funding towards specific project grants; and the rising expectations and needs of the NARS. These challenges are likely, between now and the next EPMR, to lead to radical changes in the germplasm enhancement and improvement programmes of all crops in the CIMMYT Wheat Programme. Some of the more important challenges are considered in detail below.
CIMMYT's Success
The widespread success of CIMMYT germplasm, and the fact that it, or its derivatives, now occupy about 55 million ha and account for about 80% of developing country production, means that CIMMYT has a special responsibility to ensure its varieties have effective resistance to the major pathogens (stem, leaf, and stripe or yellow rust in particular) that are capable of causing severe global pandemics. This implies that each cultivar carry "durable" resistance that is unlikely to "break down" through the evolution of new disease strains. It also implies that farmers have access to different varieties carrying different resistances so if one does "break down" then the damage is limited and resistant alternatives are on hand to ensure sustainable production.
Initially CIMMYT's approach to the development of rust resistant germplasm was to start with a very diverse gene pool, select under severe disease pressure, and test advanced lines in multiple disease hotspots globally. It was postulated that by adopting this strategy, most lines would carry multiple genes for resistance and would be unlikely to "break down" under disease pressure. Further, the different advanced lines would carry different gene combinations providing the needed diversity in production fields. This methodology worked for stem rust, for which the combination of Sr2, the adult plant resistance gene from Hope, with two or more other Sr genes has proved effective for over 30 years. However, for leaf and yellow rust, reality often fell short of expectation. It was found that despite the high levels of genetic diversity going into CIMMYT breeding programmes, the output was often relatively uniform and many lines carried the same major gene, albeit effective worldwide, for disease resistance. In the case of leaf rust, to overcome this problem, CIMMYT in the early 1980s adopted a more sophisticated breeding strategy based on the use of the adult plant resistance gene Lr34 from Frontana in combination with other minor genes. This strategy is now used routinely in the CIMMYT Programme and in other wheat breeding programmes worldwide.
CIMMYT is now in the process of putting a similar strategy in place for yellow or stripe rust based on apparently durable adult plant resistance source Yr18, first identified in the cultivar Anza. This change in direction was prompted by occurrence of severe epidemics of yellow rust on some widespread cultivars of CIMMYT origin,-first in Morocco-and then in Nepal, Pakistan, and Iran. Surveys indicate that about 25% of advanced CIMMYT germplasm which was previously protected by the major gene Yr9, is susceptible to the new race, and a further 20% are only moderately resistant.
The point is that inputting high levels of genetic diversity into a crossing programme does not guarantee a high level of genetic diversity in the final advanced lines. The recent yellow rust epidemics on CIMMYT-derived varieties once again highlight this fact. The Panel endorses the current efforts of CIMMYT to address the issue of durable resistance to stripe rust through the use of combinations of minor/adult genes for resistance. However, it suggests that if CIMMYT is to meet the threat of genetic vulnerability posed by sowing its germplasm derivatives on 50+ million ha it must:
i) continue to monitor on a regular basis the virulence patterns of all three rusts (stem, leaf, and stripe rust) in the major epidemiological regions of the developing world. CIMMYT needs this information not only to assess current threats but the likely consequences of major mutational or sexual events;ii) develop sophisticated breeding strategies that allow CIMMYT to produce effective combinations of resistance genes that provide durable protection against all existing races of the rust pathogens; and
iii) ensure, wherever possible, that NARS and their client farmers have at all times access to cultivars with different combinations of effective genes so that in the event of the development of virulent new pathogen races farmers are not faced with continuing devastating yield losses.
The Panel recognizes the difficulties in achieving (i) due to the reduction in activities in two critical rust pathology laboratories in Advanced Research Institutes (ARIs) in recent years and the difficulties in moving rust samples across national borders due to quarantine laws. However, this information is of critical importance to CIMMYT's Wheat Programme and its developing country NARS partners. The Panel, therefore, suggests that CIMMYT should, as a priority, develop this monitoring capacity using the best available science in cooperation with its NARS partners.
The Panel therefore recommends that CIMMYT:
i) initiate an integrated global programme to monitor the racial composition of the populations of stem, leaf, and stripe rust in the major epidemiological regions of the developing world, and help develop complementary research capacity in key NARS;ii) move to develop breeding strategies that guarantee CIMMYT germplasm carries effective combinations of genes to all three rust diseases.
The Cost of Durable Resistance
The Panel recognizes the desirability, indeed the necessity, of CIMMYT embracing a strategy of developing germplasm with durable resistance to all three rusts based on effective combinations of minor resistance genes. However, it also recognizes that this strategy has a cost in terms of gains made in other traits, especially yield. This cost, which is not only real but substantial, arises from the rapidly decreasing probability of obtaining desirable combinations of genes as the number of traits (and genes) under selection increases. For example, if two parents carry different favourable or unfavourable alleles at 10 different loci (say 3 for yield, 3 for quality, and 4 for agronomic traits such as height, day length response, etc.), the probability that an F2 individual from a cross between these parents carries at least one copy of each favourable allele at all loci is (1/2)10 or 1/1024. If the number of loci under consideration is increased to 20 (by adding, for example, 3,3, and 4 genes for stem, leaf, and stripe rust resistance, respectively) the probability an F2 individual carries at least one copy of each favourable allele is (1/2)20 or about one in a million.
The need for CIMMYT breeders to retain in their advanced lines combinations of effective genes for resistance will lead them to adopt more conservative breeding strategies than they have used previously. Indeed, the Panel understands that CIMMYT breeders are increasingly using limited backcrossing (with one or two backcrosses) in their programme. This approach to variety development is favoured in developed countries such as Australia, Canada, or the USA where pressure for the retention of desirable gene combinations arises not only for disease resistance, but also for end-use quality. However, as practised in those countries (where three or four or occasionally more backcrosses are used) this has proved to be a very conservative breeding strategy; the rate of increase in yield potential in these programmes has generally been much lower than that achieved by CIMMYT in the past. Indeed, in many cases the gains in yield potential that have been made have been due in a major part to the use of CIMMYT germplasm.
In light of the likely cost of breeding for durable disease resistance in terms of yield gains, and the importance of high-yielding germplasm to NARS, the Panel suggests that CIMMYT will need to put greater resources into increasing yield per se across the whole Wheat Programme. The Panel notes that CIMMYT has already made significant moves in this area with its hybrid wheat initiative and the brainstorming workshop "Increasing Yield Potential in Wheat: Breaking the Barriers". It also notes that one of its new 21 projects (Frontier Project #1) is specifically targeted at significantly improving grain yield of wheat per se above current levels. The Panel commends the Centre for this initiative.
Rapid Advances in Biotechnology
In theory, one means of reducing the impact of the need to develop durably resistant germplasm on the rate of improvement of other traits is by the incorporation of new biotechnologies into the breeding programme. Progress in wheat biotechnology and molecular genetics lags behind that in maize and barley both generally and at CIMMYT. Nevertheless, exciting progress has been made in dihaploid (DH) production protocols, the development of molecular markers [Simple Sequence Repeats (SSR) or microsatellites and Amplified Fragment Length Polymorphisms (AFLPs)], and transformation protocols in wheat and barley over the last three years. Incorporation of these techniques in the yearly breeding cycle now warrants serious consideration.
It should be noted at this point that CIMMYT has a major programme in applied biotechnology of wheat and maize. This programme and its interactions with the Wheat Programme are considered elsewhere in this report (Section 3.3). Here, the focus is on the implications of the routine use of DH technologies and molecular marker assisted selection (MAS) on the organization of the breeding projects in the Wheat Programme.
A combination of DH production and MAS, based on markers for each target disease resistance gene segregating in a population, potentially offer very substantial gains in time and efficiency in a limited backcross programme. Generally a minimum of two to three generations can be saved using DH technology while MAS can be used to ensure that only those genotypes carrying the target genes for disease resistance are tested in the field. Both DH technologies and MAS currently have technical limitations that reduce their cost competitiveness and limit their applicability to a relatively small number of selected crosses. However, these technologies are now being used by commercial companies for both wheat and barley improvement in Europe. Major advances in technology are expected to make them more competitive and widely applicable in the next two to three years.
The Panel acknowledges that the CIMMYT Wheat Programme have both DH and MAS technologies under active consideration or trial. However, planning for their possible routine use in the breeding programme still appears to be in its infancy. Yet the figures available to the Panel suggest that expenditure on wheat biotechnology (both core unrestricted and special funds) will be at least 25% of the total Wheat Programme budget by 1999 and is likely to rise rapidly in the future. Consequently there is a need for the Wheat Programme to develop detailed operational plans for the progressive changes that advances in technology will undoubtedly bring. Rational discussions on the adoption of these technologies can only be made on the basis of a detailed cost analysis of present procedures versus the new technologies. The Panel therefore recommends:
that the CIMMYT Wheat Programme develop full costing of the outputs of its present wheat, triticale, and barley breeding programmes and examine potential cost benefits of the incorporation of double haploid and marker assisted selection technologies in these breeding programmes.
Better Industrial Quality
Until recently, industrial quality (IQ) was not considered to be a high priority breeding goal at CIMMYT relative to grain yield and disease resistance. However, as the economies of developing countries improve and as trade barriers are lowered, there is a growing and widespread demand for better quality wheats among CIMMYT's partner NARS. For example, in Mexico, the price of locally produced wheats based on CIMMYT germplasm is already less than their international competitors and industry is avoiding the purchase of these wheats based on quality. This means that IQ must be given a higher priority in the future than it has in the past if CIMMYT is to maintain the same impact amongst developing country farmers.
CIMMYT has already considerably revamped its approach to IQ in its bread wheat breeding programme and this is expected to impact favourably on the overall quality of advanced CIMMYT bread wheat germplasm relatively quickly. The Panel commends CIMMYT on these changes in response to NARS needs. It notes, however, that selection for higher quality is likely to further restrict the gains that can be made in other areas, such as yield, since it involves several complex traits including flour yield and dough strength, and extensibility, and tolerance to overmixing, in addition to durable disease resistance.
Rising Expectations of NARS
If CIMMYT can routinely supply outstanding germplasm to NARS with durable resistance to stem leaf and stripe rust, then other biotic and abiotic factors will become the major constraints to yield in all environments. What may have been second-rank priorities will quickly become more important and move up the NARS priority list. These new priorities will vary amongst and within regions and will include pests and diseases such as head scab, Septoria tritici blotch, tan spot, barley yellow dwarf virus (BYDV), Karnal bunt, common root rot, crown rot, take-all and cereal cyst nematode as well as biotic stresses such as heat, waterlogging, acid soils, boron toxicity and zinc deficiency. The NARS will undoubtedly be seeking CIMMYT's assistance in meeting their germplasm needs in terms of these new priorities. However, CIMMYT is unlikely to be able to meet from its own resources the demands placed on it with respect to these regional priorities, given the efforts it will have to commit to breeding for its global priorities such as durable rust resistance.
CIMMYT therefore faces a crucial dilemma. It can restrict its attention to a small number of the more important regional priorities and it can develop new ways of working with NARS to meet all of their high priority needs. The CCER of the Wheat Germplasm Improvement Sub-programme, conducted from 20-25 March, 1994, proposed an innovative solution to this dilemma. They recommended that CIMMYT and the NARS subscribe to a vision that they might jointly redesign their wheat breeding programmes with the goal that the CIMMYT programme and the NARS programmes will function as a single interconnected collaborative Wheat Breeding Programme for the Developing World. The programme should provide maximum independence and service to individual NARS, but it also should enable all members to help each other with services they can best provide. This programme would not be a CIMMYT programme; CIMMYT would be one part of the programme. CIMMYT's particular role would be to keep the flow of improved germplasm moving at optimum speed and effectiveness; secondarily it would develop a significant proportion of finished lines, targeted for areas with most need of them. The programme might be organized as an interlinked series of Regional Programmes, with CIMMYT acting as the linker between Regional Programmes.
This proposed Wheat Breeding Programme for the Developing World is visionary and can never be realized in full because of differing national goals and international rivalries. But we believe that to have this vision and to work towards it with hopeful resolution is better than to do nothing. We believe that this vision is the logical next step of CIMMYT's efforts to help the poor and disadvantaged people of the developing world; and that significant steps in that direction can be taken in the near future.
The Panel recognizes that CIMMYT has developed very significant joint breeding activities with key NARS partners in addition to its long-standing joint activities with Mexico - for example, with Brazil in developing acid soil tolerant germplasm and with China in scab resistance breeding. However, it has not fully embraced the concept proposed by the CCER as a means of meeting the diverse priorities of its NARS partners. The Panel recognizes that many NARS lack the facilities and staff to participate fully in joint breeding activities. But equally there is a growing list that can now, or will be able to do so in the future. The Panel strongly suggests that CIMMYT now fully embrace the above concept and move towards its implementation as speedily as possible.
Reduction in Unrestricted Core Funding - Differential Impact on Triticale and Barley Research
The last five years have seen a sharp change in the balance of funding available to CIMMYT between unrestricted core, restricted core and special project funding. Unrestricted core now represents only about 50% of CIMMYT's total budget. This change has had a significant effect on all CIMMYT programmes. However, it has had much more severe consequences for triticale and barley, because the research programmes of both crops are small and largely funded from unrestricted core. The Wheat Programme has been less effective in attracting restricted core and special projects funding than other CIMMYT programmes and this is especially true for the triticale and barley components.
Further reductions in unrestricted core funding which seem likely if not inevitable will put severe funding pressure on triticale and barley research. Both are now funded near their minimum acceptable levels and further funding cuts would threaten the viability of these programmes.
The Panel notes, for example, that there is no interaction between the Applied Biotechnology Centre and the Wheat Programme with respect to these crops. This is despite the fact that research on barley biotechnology and molecular genetics is more advanced globally than it is for wheat, and further, that the barley breeder has established a cooperative venture with Oregon State University for using molecular markers to map a number of disease resistance genes.
The Panel therefore recommends:
that the Wheat Programme make a concerted effort to seek additional funding for triticale and barley research without which the future viability of these programmes is at risk. In the case of barley, this needs to be done in close collaboration with ICARDA. If this is not possible, or not successful, then serious consideration will need to be given to the discontinuation of the breeding of these crops.
2.2.1. Introduction
2.2.2 Evolution
2.2.3 Achievements and Impacts
2.2.4 CCERs
2.2.5 Emerging Challenges and Future Strategies
2.2.6 Conclusions
The CIMMYT Maize Programme's mission is to help the poor in developing countries by increasing the productivity of resources committed to maize, while protecting natural resources.
Over the next 30 years, maize demand will grow at an annual rate of 2.2%. To meet this demand, yield increases will then need to be above 1.2% per year, because cultivated area is projected to increase by less than 1% per year. By 2020, developing countries will produce half of the total world supply of wheat and maize and consume 55% of this total, while importing 61 million t of maize annually.
In this scenario, maize is a strategic crop because it represents a major source of energy, protein and forage in all continents of the world. In the developing world, and particularly for stress environments, maize research has been addressing demands for higher grain yields while minimizing requirements for inputs. This strategy requires germplasm that is adapted to less favoured environments (marginal areas). Furthermore, the tropical regions of the world face increasing environmental pressures, decreased availability of labour, and a tendency to market domination by multinational companies in the areas of maize breeding, biotechnology, seed production, and trade in grain.
Although the structure of the Maize Programme has changed since 1988, the general objectives of the Programme remain the same. They are to preserve, improve, and disseminate genetic resources; develop environmentally compatible crop management practices; and to provide research methodologies and information through training and consulting.
The Programme adopted the mega-environment concept, of which the most important for CIMMYT's mandate are environments in tropical regions (lowland 54 million ha; mid-altitude 8 million ha; highland 6 million ha) and in sub-tropical regions (8 million ha).
In the light of the current world situation, CIMMYT's Maize Programme has identified the following themes/areas, in which the Centre can be considered to have a comparative advantage over other public and private organizations.
· Conserved but available genetic variation - CIMMYT's ex-situ germplasm collection.· Globally or regionally evaluated public research goods - lines, topcrosses, germplasm complexes, and germplasm selection methods - especially those appropriate to the lowland tropics.
· Open-pollinated varieties with high, stable yield and broad adaptation.
· Publicly available elite inbred lines with high and known general combining ability (GCA).
· Sources of tolerance to specific abiotic and biotic stresses - lines, synthetics, varieties, and populations.
· Molecular genetic information: linkage maps and probes.
· Publicly accessible regional research networks.
· Hands-on training that provides skills in practical breeding and on-farm crop management research obtained by working closely with internationally known maize researchers.
· Strategic crop research information on maize-based systems in the tropics.
· Research consultation at no cost to national researchers.
· An institution that serves as an "honest broker" for intellectual property lines, gene constructs (e.g., Bt), biosafety information - on behalf of national programme scientists with little purchasing power and leverage. CIMMYT may also be the only ultimate source of transgenics for traits which have little commercial value in the north.
CIMMYT's current MTP (pp. 16-17) distinguishes four generic types of activities: 1) strategic research, 2) applied or adaptive research, 3) technology delivery, and 4) human capital development. Specific outputs from these activities in CIMMYT's Maize Programme are:
· Germplasm with efficient input use, input-responsiveness, stress tolerance, and broad adaptation, suited to the needs of maize production mega-environments in the lowlands, mid-altitude/sub-tropical, and highland zones. In the majority of cases, these will be inbred lines of good general combining ability, possessing the capacity to produce high-yielding, stress tolerant, and stable hybrids and synthetics.· Source germplasm (lines, synthetics, populations) with tolerance to specific stresses (e.g., soil acidity, drought, low N, borers, and specific diseases).
· Conserved, accessible genetic variation. This is usually in the form of ex-situ preservation in the Genetic Resources Centre, but in future may also be in-situ preserved genetic stocks that evolve with the cropping systems and climate.
· Efficient selection methodologies: CIMMYT has the opportunity and the responsibility for developing effective and efficient methods for germplasm improvement by national programmes.
· Environmentally compatible, maize-based management practices that complement the properties of input-efficient and input-responsive germplasm without threatening the quality and quantity of natural soil and water resources.
· Trained national researchers with practical hands-on research skills and a field orientation.
· Information imparted through direct consultation with NARS, published documents, public databases (e.g., on the Internet, audiovisuals, etc).
The Maize Programme research team is highly qualified and conducts research of excellent quality and relevance within its targeted area. Following the financial cuts of the early 1990s, however, there are now only 23 internationally recruited staff (IRS) in the Maize Programme, which represents 74% of the IRS in 1991. At present, 57% (13 IRS) of the senior staff are located in outreach (Guatemala, Colombia, Ethiopia, Zimbabwe, Kenya, and Thailand) and 43% (10 IRS) are based at Headquarters. In addition to the 23 IRS, the programme also has 12 researchers who are post-doctoral or visiting scientists.
The MTP continues to use the mega-environment concept for germplasm and outputs, but puts more emphasis on a more integrated and multidisciplinary approach between and within research programmes, and with CIMMYT's partners. This transition is embodied in the new project management structure of the 1998-2000+ MTP. The Maize Programme is involved in 15 projects (five global, four regional, and six frontier) and has the responsibility for coordinating seven projects.
The MTP also represents a shift in emphasis to redirect more effort to less favourable environments to meet the challenges of poverty reduction, preservation of biodiversity, and natural resources. For the Maize Programme, this shift takes the form of increased research directed to abiotic stress tolerance, the use of marker-assisted selection to accelerate this breeding effort, greater investment in regional projects in SSA, and stronger linkages with the Natural Resources Group (NRG) and the Economics Programme.
In global projects, the main products are enhanced germplasm; regional projects focus on the interactions between germplasm, management, natural resource conservation, and socioeconomic issues; frontier projects enhance the application of advanced scientific methodologies that will facilitate research in the global projects. This set of projects offer, if well managed, an excellent opportunity for interaction with diversified partners such as ARIs, NARS, NGOs, and the private sector.
CIMMYT's Maize Programme has made substantial contributions to increasing maize productivity and production in developing countries.
i) One estimate made in 1994 suggests that 445 of the 842 public maize varieties released in developing countries during 1966-1990 contained some CIMMYT germplasm. CIMMYT-based open pollinated varieties (OPVs) and hybrids were grown on nearly 13.5 million ha, with seed for 12.1 million ha provided by the public sector and for 1.4 million ha by the private sector. The relative importance of public and private institutions in the provision of seed has been changing lately, with the private sector assuming greater importance.ii) The latest available information reveals that the Programme has developed and released 366 inbred lines for use by public and private institutions. Nearly 80% of the improved maize varieties currently released by the public sector in developing countries contain CIMMYT germplasm and such cultivars are grown on about 21 million ha, contributing approximately one billion dollars annually to their economies. Efforts are underway to update the Programme's impact and the contribution of CIMMYT's germplasm in currently grown improved cultivars and it is expected to be greater than that last estimated for 1994. CIMMYT's Maize Programme has the world's largest research network for maize: research is conducted in collaboration with over 80 countries and about 500 maize germplasm evaluation trials are distributed to NARS each year.
iii) The involvement of both the public and private sector in maize seed production makes impact assessment difficult because the private sector has been reluctant to provide information on the use of CIMMYT materials for reasons of confidentiality. Companies who receive CIMMYT lines are not obligated to recognize this contribution or provide information about their utilization in commercial products, although this situation is improving. The same occurs with OPVs, although in this case it is easier to gather information. Despite these difficulties, the EPMR believes that the available information suggests that CIMMYT's germplasm has made significant contributions to the improved OPVs and hybrids used on 58% of the maize area in developing countries.
iv) Significant progress has been made in developing selection techniques for tolerance to drought and low N availability. Tolerant, elite, open-pollinated populations and synthetic varieties have been improved and released. In particular, the crop physiology research that has led to the development of selection methods for identification of maize genotypes tolerant of drought and low N is well published and of high scientific quality and relevance. The EPMR Panel commends this research. Recently, one project has been established in sub-Saharan and another in East Africa to use these new selection procedures to identify adapted maize OPVs and hybrids with tolerance to drought and low N.
v) Another significant finding is that stress-tolerant materials are also capable of maintaining their yield advantage in favourable environments, which indicates broad adaptation. For the acid soils of Colombia, CIMMYT researchers have also produced new maize germplasm that tolerates high soil A1 levels. This achievement came from a cooperative research network with NARS in which selection methods were developed and germplasm was generated and evaluated. The result was the release of variety CIMCALI 91SA3 (Sikuani V-110 in Colombia), and the expected release of hybrids with high yielding potential.
vi) Molecular tools are in the early stage of utilization in the Maize Breeding Programme. The exploratory use of these tools has occurred in collaboration with the ABC. Molecular markers for anthesis-silking interval (which is associated with tolerance to drought and low N), resistance to streak virus, borers, ear rot, and tolerance to soil acidity have been, or are in the process of being, identified. CIMMYT is in the process of testing Bt maize in greenhouse and field trials. Bt toxin production has been evaluated under abiotic stress conditions to verify the effectiveness of transgenic expression under conditions that will occur in farmers' fields. Transgenic lines have been used for Bt gene transfer to 10 tropical inbred maize lines through backcrossing.
vii) The regional programme based in Zimbabwe has developed materials with resistance to streak virus and other foliar diseases and tolerance to borers and weevils. In Asia, progress has been made in the simultaneous improvement of yield and resistance to downy mildew. In East and West Africa, maize researchers have developed lines and hybrids that yield more than non-tolerant germplasm in both the presence and absence of Striga.
viii) In the hillside maize systems of Central America, a CIMMYT network conducted adaptive research on conservation tillage, mulching, and green manuring that documents the benefits of these technologies and uses on-farm trials to test them in farmers' fields. These practices have the potential to improve soil quality and productivity in El Salvador, Guatemala, Honduras, Nicaragua, Panama, and Costa Rica.
ix) The Maize Programme has an impressive record in training scientists from developing countries. Since 1966, approximately 3,800 scientists have received training at CIMMYT's Headquarters in breeding, agronomy, pathology, entomology, seed issues, quality protein maize (QPM), and other areas. Approximately 3,500 scientists have also been trained through in-country and regional training courses. CIMMYT now collaborates with NARS in Brazil, Kenya, and Thailand to provide agronomy training courses in those countries. These training courses have reached an additional 300 NARS scientists. Over 1,000 senior scientists from NARS have visited CIMMYT Headquarters or its regional programmes to acquaint themselves with modern research methodologies and germplasm. The programme has been associated with undergraduate and graduate thesis projects of nearly 210 NARS scientists from 49 countries.
x) The Maize Programme has recently organized a series of conferences on several important topics: Insect Resistant Maize: Recent Advances and Utilization, attended by 40 developing countries scientists, November 1994; Developing Drought and Low N-Tolerant Maize, attended by 70 national programme representatives, March 1996; the Genetics and Exploitation of Heterosis in Crops, attended by 500 scientists, August 1997.
Four centre-commissioned reviews have been conducted of subprogrammes or breeding methods in the Maize Programme over the past five years. These included reviews of (1) maize international testing and population improvement, 1992, (2) subtropical mid-altitude and highland maize subprogramme, 1993, (3) lowland tropical maize subprogramme, 1994, and (4) breeding strategies and methodologies of CIMMYT's Maize Programme, 1995. All of these reviews focused on the quality, efficiency, and improvement of CIMMYT's maize breeding research.
The first CCER related to the need for clustering populations by heterotic groups, to accommodate hybrids in international trials, to identify "key site" locations, and to improve coordination between Headquarters and regional programmes. An integrated system for managing trial data was also proposed. The second CCER made recommendations on testing environments for population improvement and line extraction, special populations (drought tolerance and insect resistance) and evaluated the stage of development of collaborative projects. The third CCER reviewed the lowland tropical maize subprogramme and discussed the role of NARS and the private sector in this mega-environment, germplasm development efforts (population improvement and hybrid development), and the need to incorporate multiple stress tolerance and improved grain quality in appropriate germplasm. The review team emphasized the need to evaluate the utility of marker-assisted selection as a breeding tool for complex traits.
The fourth CCER reviewed breeding strategies and methodologies. It generally endorsed the strategies of the Programme, made suggestions to enhance the work, and recommended that population improvement should not be de-emphasized despite increased focus on hybrid breeding.
The EPMR Panel found these peer reviews useful, but notes that they did not address broader cross-cutting strategic issues or subjects other than breeding.
The Maize Programme will face major challenges in the future related to improving maize yields and yield stability in marginal environments, the need to protect soil resources and environmental quality, and increasing use of hybrids and improved OPVs. Another major issue concerns the lack of adoption of improved maize varieties on 42% of the maize production area in developing countries. These areas are typically regions of rural poverty and marginal soils. The Panel considers the transfer of improved maize germplasm into these areas to be one of CIMMYT's major challenges.
Strategic Issues in Future Planning
The Maize Programme has invested heavily in developing regional projects that foster collaboration with NARS in germplasm development. The EPMR commends this commitment to outreach and believes that these regional projects are making important contributions. However, the capacity of the Maize Programme to develop improved OPVs and hybrids for use by NARS, private companies, and farmers can be increased in the following ways:
i) The programme should re-examine the rationale for resource allocation to OPV and hybrid development and improvement efforts. It needs to develop more appropriate populations (many current ones are nearly 40 years old and have contributed little), using old and new elite germplasm from CIMMYT and NARS and to improve them using methods that enhance their performance per se and in hybrid combinations. The programme should integrate its yield improvement and stress tolerance breeding efforts to develop cultivars that provide high and stable yields. The efficiency of this effort will be greater if germplasm is tested in the most appropriate environments. Identification of appropriate environments can be facilitated by collaboration with the NRG and use of existing information, experience, and GIS databases.The EPMR Panel recommends that the CIMMYT Maize Programme:
place greater emphasis on the development of new heterotic populations that incorporate both improved yield potential and increased stress tolerance, and make these populations available to NARS and the private sector.ii) There are other key issues concerning the lack of adoption of hybrids and improved varieties in some regions. (1) Why has the use of hybrid maize varieties been slow to replace OPVs in many parts of Africa despite the significant potential yield advantage of the available hybrids? (2) Why have QPM varieties had little or no impact despite documented advantages with regard to children's nutrition and livestock production efficiency (see Economics Programme and Programme Linkages sections)? The Panel is not convinced that these questions have been adequately addressed and believes that a more thorough analysis is required to ensure appropriate strategic planning.
iii) Linkages are not obvious for germplasm enhancement activities among outreach sites and between outreach sites and Headquarters. These efforts need to be integrated where appropriate, ensuring a reciprocal flow of germplasm and information. CIMMYT's regional programmes need to develop closer links with relatively stronger NARS in their regions to increase efficiency and productivity. Such NARS can provide a larger pool of human resources, research infrastructure, experience, and germplasm to complement CIMMYT's resources at little additional cost.
The EPMR Panel recommends that the CIMMYT Maize Programme:
increase the flow of information and germplasm between maize researchers in Regional Projects and at Headquarters by convening an annual meeting that includes maize scientists involved in germplasm improvement.iv) Significant progress toward development of materials with resistance to most of the tropical and subtropical diseases has been made in the programme. However, some diseases are spreading (e.g., downy mildew has moved from Asia to Africa and Latin America and stunt has moved from its traditional habitat in Central America to most countries in Latin America). Other diseases are already quite widespread (e.g., ear rots, stalk rots, turcicum, rusts), and some are becoming important (e.g. Phaeosphaeria in Brazil). The programme should take a closer look at integrating disease resistance efforts between outreach sites and between outreach and Headquarters to avoid duplication and to increase efficiency.
v) While significant progress has been made toward enhancing resistance to, and tolerance of, some Latin American insects, greater efforts are needed on others, such as army worms, ear worms, and weevils. Less work on insect resistance/tolerance has been conducted in Africa and Asia, and increased effort is needed here as well. The programme should establish strategic linkages with appropriate institutions in Latin America, Asia, and Africa to achieve this goal.
vi) Several molecular markers for important maize traits are now available for use in the Maize Breeding Programme. Most promising are markers for anthesis-silking interval (drought and low-N tolerance) and resistance to borers. Both traits are under complex genetic control and are, therefore, difficult to select by conventional breeding methods. The use of molecular markers would accelerate selection procedures. Although these molecular markers are now available, marker-assisted breeding methods are not yet utilized in the main line breeding programme.
The EPMR Panel recommends that the CIMMYT Maize Programme:
fully incorporate marker-assisted breeding approaches into the mainstream maize breeding effort, which will require clarification of the roles and responsibilities of the Maize Programme and the Applied Biotechnology Centre.vii) More agronomic research is needed to support germplasm improvement efforts on OPVs and hybrids. In most cases, adoption and full exploitation of the genetic potential of these materials cannot be expressed without improved management. Continued efforts are encouraged on soil fertility and nutrient management, crop rotation, intercropping, and improved fallow systems that enhance productivity and sustainability for resource-poor farmers. For high-potential areas, old management technologies and modern cultivars provide little benefit. CIMMYT should assist NARS to develop agronomic practices that match the enhanced high yield potential of hybrids and OPVs in these more favourable environments. Use of conservation tillage is expected to increase as is presently occurring in Brazil. The EPMR Panel believes that CIMMYT can play a leadership role in facilitating the development and adoption of appropriate conservation tillage systems for maize production in other developing countries. Much of this agronomic research must be conducted in the regional projects. The EPMR Panel encourages CIMMYT to continue its investment in upgrading the agronomic research capacity of its outreach programmes and in collaborating with NARS at these sites.
viii) CIMMYT must continue its emphasis on training. Training in modern research methods, biotechnology, and specific issues in breeding, entomology, pathology, and physiology are especially needed to enhance NARS capacity to conduct high quality research. CIMMYT must also maintain its commitment and support to, and involvement in, the recently developed training activities in partnership with NARS to ensure the effectiveness and sustainability of those efforts. In-country and regional training courses can be organized in collaboration with relatively stronger NARS in the regions to enhance relevance of the courses, to reduce expenses, and to maximize spill-over effects.
Public and Private Sector Relationship
Public sector research and extension in developing countries is often poorly funded and, in many NARS, financial support for these programmes is declining. Traditionally the NARS have been CIMMYT's most important partners. Static or declining strength of NARS directly affects CIMMYT's ability to serve the poor. This situation strongly suggests that regional networking is the best way to ensure a critical mass of national programme staff and expertise, a shared well-focused research programme, adequate research planning, and long-term funding (see Section 3.6, Regional Programmes). If NARS are not able to release new cultivars that reach the farmers, they have little probability of impact, with consequent poor acceptability by society. Cultivar development is, therefore, not enough to justify these programmes if the materials generated do not reach the farming community, the companies, and the market in general.
Traditionally, CIMMYT has been associated with NARS in cultivar development, training, and consulting. However, to help ensure continuity of these programmes, it is necessary to develop new strategies to channel their products to the farmers. In many cases, NARS do not presently have the resources to properly develop and support the strengthening of seed production and distribution efforts of NGOs and regional seed companies. CIMMYT should devote greater attention to developing linkages between NARS and local, regional, and national seed companies. One way to achieve this is by developing a training course on seed marketing and production that would be a joint collaboration between NARS, commercial seed companies, and CIMMYT. This course would help build the capabilities of the private companies and NARS to produce high-quality seeds (with quality control assistance) at competitive prices, in order to satisfy local market requirements. It is important to point out that this strategy should not only be initiated with single-cross hybrids. Because of their characteristics, in terms of facility of production, seed costs, and other factors, three-way and double-cross hybrids are likely to be more appropriate to initiate such a process. Balanced emphasis should be given to both small and large companies within a country, and CIMMYT must also maintain an open-door policy toward multinational seed companies as well.
In some countries, CIMMYT has forged successful alliances with NARS and private seed companies and these alliances have increased the utilization of improved maize germplasm by farmers. The EPMR Panel believes that CIMMYT can play a catalytic role in stimulating the development of similar alliances in other countries and, where feasible, foster the development of additional private seed companies.
Inbred lines developed by CIMMYT, crossed to testers from national programmes and private companies, could generate materials which could be useful to help establish a good system of interaction for the production of improved commercial cultivars. In this case, international cooperative trials could include new combinations of specific interest to the regions involved in the collaboration. This would provide national and multinational seed companies with an opportunity to incorporate more CIMMYT lines into their programmes. CIMMYT, in turn, would benefit from the credit given to this participation, thus helping to correct the present situation in which it is difficult to measure CIMMYT's contributions through private programmes.
Improved Germplasm for Less Favourable Environments
CIMMYT has made significant progress in gaining increased understanding of physiological traits associated with abiotic stress tolerance and using this knowledge to develop improved breeding strategies. In particular, progress on tolerance to drought, low-N, and soil acidity has been notable. If adoption by resource-poor farmers, farming marginal soils, is to succeed at the physiological and breeding level, the Panel sees three major challenges:
i) Although 58% of maize area in developing countries is planted to improved varieties, 42% is not and there has been little progress in increasing the adoption rate. The reasons for lack of adoption are fundamental to CIMMYT's strategy and yet the EPMR Panel could find little documentation concerning this issue. There is an urgent need to understand why over 40% of the area sown to maize is occupied by unimproved varieties (compared to less than 20% for wheat). Is lack of adoption the result of preference (e.g., unacceptable quality or other traits), access to seed, or poor performance of the available improved varieties under on-farm conditions?Therefore, the EPMR Panel recommends that CIMMYT:
thoroughly investigate the reasons for lack of adoption of improved maize OPVs and hybrids on more than 40% of the maize area in developing countries.The Panel understands that this effort will require direct input from the Maize Programme scientists in collaboration with the Economics Programme and the NARS.
ii) Germplasm alone is not sufficient to achieve a sustainable positive impact on productivity in marginal maize-growing environments where drought, low soil fertility, and soil acidity are major constraints. In addition, agronomic practices are required that amplify the benefits of the stress-tolerance advantage and that conserve soil resources. Because most cropping systems in stress environments with poor soil fertility are at steady-state with regard to input and output of nutrients, maintaining the yield advantage and greater nutrient removal in harvested grain of stress-tolerant germplasm will require additional input of nutrients. Otherwise soil fertility will be depleted. Therefore, nutrient use efficiency of these materials, as well as the nutrient management practices to sustain soil fertility, are key issues. The EPMR Panel believes that stronger efforts on agronomic and natural resource issues related to use of stress-tolerant germplasm are required in the Global and Regional Projects related to stress tolerant maize.
iii) Although there is a growing tendency for the utilization of hybrids (in 1992, 44% of the 83.6 million ha in the tropical and sub-tropical regions were grown with hybrids compared with 38% in 1985), in some regions it is still incipient or remains static, which indicates considerable room for the utilization of improved OPVs (in 1992, 14% of the area in LDCs utilized improved OPVs). In several of these regions there are local private companies that produce OPVs at prices that are acceptable to farmers. Many of these companies provide, in addition to seeds, assistance and information that helps farmers to improve their production efficiency.
Another important aspect of OPVs is that their use is usually a necessary step to help farmers understand the importance of using improved seeds of good quality and to open the door on the use of improved agronomic practices. After a first contact with improved OPVs, the farmer is usually better able to decide about the necessity for adopting hybrids.
Besides commercial production, the seed of OPVs can also be locally produced by farmer communities, as extensively demonstrated in Brazil. These experiences show that the improved seed is a "technological vehicle" that stimulates the adoption of better crop management practices, product conservation, and specialty maize utilization (e.g., QPM).
The overall assessment of the Maize Programme is very favourable. The programme has had a significant impact on the availability of improved hybrids and OPVs in developing countries. Scientific quality and productivity has also been excellent. In particular, the research on the physiological determinants of stress and selection methods for identifying stress-tolerant maize germplasm has provided new opportunities for improving maize performance in marginal environments. The EPMR Panel commends these achievements.
