A new strategy and newsletter set out the argument for, and the specifics of, better conservation and use of tropical and subtropical forages.
A much-declined skills and resource base for tropical and subtropical forage work is occurring in the face of increasing demand for livestock products and forages across livestock systems in the tropics.
Greater efficiencies, effectiveness and collaborations in tropical and subtropical forage collection, conservation and use will help maximize the diversity, rationalize the conservation and optimize the health and use of germplasm held in international and national genebanks.
Author of the forage strategy, consultant Bruce Pengelly, a forage specialist who formerly worked with Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the CGIAR Bioscience eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, along with Brigitte Maass, a forage agronomist and associate professor at the University of Gottingen and formerly of the CGIAR International Center for Tropical Agriculture (CIAT), have just announced the first issue of a forage newsletter they are producing, under the auspices of the Global Crop Diversity Trust, that is a first step in fulfilling on the new strategy.
Here is how Pengelly and Maass describe their newsletter.
It is our pleasure to share the first Newsletter on Forages for the Future with you.
The newsletter is meant to start building again a community that is interested and engaged in tropical and subtropical forage genetic resources, their conservation and utilization.
In the lead story of the newsletter, Pengelly reports on the results of a 2015 global survey: ‘There are at least 6 large genebanks and a number of smaller centres focusing on tropical and subtropical forages. The main centres were the international centres of CIAT and ILRI and the national centres of Australia, Brazil, USA, and South Africa. All of these have collections of between 7,000 and 21,000 accessions and most report that they have good storage conditions. That’s the positive news. . . .
‘A significant number of respondents to the survey reported that less than 10% of collections were backed‐up in other institutes, national or international.
Other stories in the newsletter:
- Native Brachiaria germplasm of Uganda
- Guineagrass breeding in Brazil
- Using Gliricidia sepium in Indonesia
Read the first issue of the newsletter: Forages for the Future, Global Crop Diversity Trust, Feb 2016. The next issue is due in Aug 2016. To subscribe or share your forage stories with the global community, contact Brigitte Maass (Brigitte.Maass [at] yahoo.com).
As Chris Jones, the British forage biotechnologist who leads ILRI’s Feed and Forage Biosciences program, says:
‘The tropical and subtropical forage strategy was initiated at a meeting of forage and genebank experts held in Bonn last October . I have been recruited as a member of a core group, with representatives from national and CGIAR centres, to guide strategy implementation. This is the first of a series of newsletters outlining the strategy and highlighting activities and opportunities in its development. I’d encourage all interested to engage in future activities and editions.’
What follows is a summary of Pengelly’s strategy document.
Tropical and subtropical forages are critically important for the supply of livestock feed and environmental services. But support for the collection and conservation of these forages, and research on their diversity, has declined significantly since 1990. This decline, which has reduced capacity and knowledge in the networks of national and international genebanks that maintain the world’s tropical and sub-tropical collections, has (strangely) coincided with a rapid growth in demand for livestock products across the developing world. This decline thus needs to be redressed, and quickly, if the tropical and subtropical world is to have access to the best forage material and knowledge to meet its growing demands for more and better food and natural resource management.
About the new forage strategy
A new strategy has been developed with input from across the tropical forage genetic resources community. The aim of the strategy is to rebuild a strong, functional network of national, regional and international tropical and subtropical forage genetic resource centres and genebank users. Such a strengthened network will help improve the conservation and study of the most important germplasm by introducing efficiencies and greater rationalization within and between genebanks. It will help raise the game for genebank managers, enabling them to play more central roles as knowledge managers and advisors in wider research and development programs. And it will help genebank staff to anticipate germplasm needs and respond more directly to user requests for information and seeds.
Development of the strategy has been supported by three activities. Discussions were held with national and international genebank managers between Apr and Jun 2015 to gain their views. A survey of key tropical and subtropical forage institutions at the national level (genetic resource centres in Australia, Brazil, Kenya, Mexico, South Africa, USA), subregional level (the Southern African Development Community centre in Zambia) and international level (CIAT, ILRI, ICRAF) was conducted in Aug 2015. A workshop of genebank managers and forage specialists was held at the headquarters of the Global Crop Diversity Trust, in Bonn, Germany, in Oct 2015.
The need for a strategic plan to conserve and use tropical and subtropical forages is arguably greater than that for other ‘crops’. That’s because tropical forage plants are usually not regarded as a commodity in themselves, are made up of a large range of species, and are often being conserved in poorly resourced genetic resource centres in developing countries. Forage plants in addition have special biological challenges —made all the more difficult to address by reduced agricultural research-for-development funding in recent decades. The need for a strategy is strengthened further by the broadening role of tropical and subtropical forages beyond livestock feed to environmental uses such as control of soil erosion, green manure crops and sources of biomass for biofuels.
The aims of this strategy will take many years to achieve—but they will not be achieved without first rebuilding community, value, capacity and efficiency.
About legumes and grasses
The tropical and subtropical forages being collected and conserved comprise mostly the many legume and grass genera and species that have contributed to the development of livestock feed systems or that have been collected with this potential in mind. The region of Central and South America and the Caribbean is the key centre of diversity for forage legumes while sub-Saharan Africa is the key centre of diversity for forage grasses. (Among exceptions to this are important legume genera such as Stylosanthes, Leucaena, Desmodium, Centrosema, and Gliricidia, which are primarily American in origin, while important grass genera such as Urochloa (syn. Brachiaria), Pennisetum, Megathyrsus (syn. Panicum) and Digitaria have predominantly sub-Saharan African origins.)
On the importance of forages
Tropical and subtropical forage genetic diversity has improved livestock production in many environments and farming systems, particularly over the last 50 years. These forages have underpinned large-scale pasture-based beef production in the subtropical and warm-temperate regions of North America, South America (especially Brazil), and northern Australia; have provided the essential feed-base for more intensive small- to large-scale livestock production systems, including beef, small ruminant and dairy production; and are important in feeding pigs in some regions. These forages have benefited sown pastures and alley cropping as well as agroforestry and cut-and-carry production systems, to name some.
The economic importance of tropical and subtropical forages is rising fast along with the fast-rising demand for, and consumption of, milk, meat and eggs across the developing world, while the environmental benefits tropical forages deliver—such as storing carbon, reducing soil erosion, reducing use of nitrogen fertilizers in green manure systems, and reducing greenhouse gas emissions generated by ruminant livestock—are also increasing in importance. Some tropical forage species, such as Napier grass (Pennisetum purpureum) and switchgrass (Panicum virgatum), have potential for use as feedstocks for cellulosic biofuels. And some tropical grasses have become important in recreation use, where they are widely used for turf.
On breeding programs
Breeding programs to develop forage cultivars have been used over the past 50 years with some outstanding successes, such as the introduction of resistance to major pests and diseases. While major breeding programs stopped being conducted in Australia after about 1990, the USA has a number of active breeding programs conducted by the United States Department of Agriculture and the University of Florida. International centres have continued investment in major breeding programs. A program on Urochloa (syn. Brachiaria) spp. conducted by the International Center for Tropical Agriculture (CIAT) has been one of the largest and most sustained, releasing several new cultivars in the past decade. Brazil also conducts forage breeding programs (on Urochloa, Pennisetum and Megathyrsus maximus [syn. Panicum maximum]). ILRI is working with dairy scientists at the Brazilian Agricultural Research Corporation (EMBRAPA) to exchange Napier grass materials and has initiated a molecular biosciences program to exploit the variation found in Napier and other species it holds in its forage genebank.
There are probably less than ten major breeding programs operating today worldwide on tropical and subtropical forages. Far more frequently, cultivars have been developed by comparison among wild populations and/or selections from within wild populations. Some of the most important tropical and subtropical forage cultivars have been commercialized through straight selection from wild populations.
Tropical forage germplasm collections contain more diversity than any other crop or forage collection in terms of numbers of genera and species. As in all forage collections, grasses (Poaceae) and legumes (Fabaceae) dominate. The collections contain about 600 recognized genera and most of those are represented by more than one species. ILRI reports it alone has some 1400 species in its collection. There is also diversity in form: while herbs dominate, climbers, shrubs and trees are all represented and each form by several species.
Unconvinced? Here are another nine reasons
1 We’re losing forage genetic resources along with habitats
Many of the forage accessions currently held ex situ (removed from their natural habitats) are from regions that have undergone significant land-use change over the past half century. Much of the forests, grasslands and savannahs in South and Central America, for example, have been replaced with urban infrastructure. Expansion of agriculture in Brazil in particular has transformed vast natural forests and grasslands into intensive soy and other croplands or into improved monospecific pastures. Brachiaria brizantha cv. Marandu, for example, now grows on some 60 million hectares (148 million acres) of Brazilian land, forming a dangerously narrow genetic base. Development and population growth in many parts of Africa have resulted in expansion of cropping and overgrazing of rangelands, which has also reduced biodiversity. These changes across the tropics have made the tropical and subtropical forage germplasm already held ex situ extremely valuable, and sometimes irreplaceable.
2 Forage plants are wild relatives of crop plants
The world’s tropical and subtropical forage collections contain several species that can be considered crop wild relatives. Some are known to be wild types of the same species as major crops. Others will require a more detailed understanding of taxonomy and species to sort out their relationships to crops. The forage genus Rynchosia and, until recently, the genus Atylosia (now Cajanus), for example, are both close relatives of pigeon pea (Cajanus cajan). Many crop breeders do not even know this material exists. To contribute to crop plant improvement, there needs to be easier and better access to information on what forage genetic materials are being held and where.
3 Resources for forage work has declined big time
Investment in the conservation and use of tropical and subtropical forages, unlike that of crop plants, has declined since about the 1990s, even in those developed countries and emerging economies, such as USA, Australia, South Africa and Brazil, that have significantly benefited from investments in forage conservation and use. This investment decline over the past 25 years is evidenced by the poor viability of many tropical forage collections, the fewer staff and resources for collecting forage resources and managing forage collections, loss of expertise and use outdated genebank operating systems. Policymakers and donors need to be convinced of the greater roles that conservation, research and use of tropical forages can play in food security, enhanced livelihoods and healthy environments.
4 Scientific staffing for tropical forage work has declined drastically
Until the 1990s, CIAT, ILRI, Brazil’s EMBRAPA Brazil, Australia’s Commonwealth, Scientific and Industrial Research Organisation (CSIRO) and other institutes employed more than 250 scientists specializing in tropical and subtropical forage genetic resources. The number of active, employed tropical and subtropical forage scientists is now probably less than 30 and the bulk of knowledge built up over many decades now rests with about 40 mostly retired scientists.
5 Forages possess exceptional diversity
ILRI reports about 600 genera and 1400 species in its collection of tropical and subtropical forages, while CIAT holds about 730 species. And there are other taxa held in national genebanks that are unrepresented in the collections of ILRI, CIAT or the World Agroforestry Centre (ICRAF). Preservation of this exceptional diversity will require that genebank managers and researchers stay abreast of continuous changes in taxonomy and technical issues in such matters as viability testing, seed dormancy, seed longevity, security backups, pollination and pollinators, diseases, day length sensitivity, ploidy levels and the wide range of breeding systems. While there is much diversity, less than 100 species have proven useful as forages to date. This means that 1200 species of limited or no immediate forage, feed or environmental value are being conserved globally. This does not mean that 86% of the accessions held are of limited value. The largest collections of any one species are mostly those perceived to have had the greatest potential value, and hence, most plant collecting focus. This is reflected in CIAT’s genebank, where 45% of the accessions of some 730 forage species are from just 20 species.
6 Transformational technologies are opening new frontiers in forage research
Dramatic advances in bioscience technologies have transformed tools for understanding the vast genetic diversity, and potential use, of crop and forage plants and their wild relatives. While exploiting this plant diversity to overcome climatic and other agricultural constraints is now possible due to the explosion of breakthroughs in genomics and related fields (‘genotyping’), practical outcomes of use of these ‘omic technologies’ depend on knowledge of the plants’ observable traits (‘phenotyping’) and possibilities for their adaptation and use.
7 Selection and seed availability both need speeding up for scaling up
With so many tropical and subtropical forage species and genotypes proven to be useful in particular environments and systems, livestock programs need to be able to access the best advice from forage specialists using the best selection tools. But such selection of well-adapted germplasm needs to be followed by ready availability of viable seed (or vegetative planting material) in sufficient quantities for quick evaluation and use at scale.
8 Current CGIAR forage work is insufficient
CGIAR genebanks comprise the largest and among the most diverse collections of tropical and subtropical forages in the world. These international collections also provide some backup storage for other collections and tend to be better resourced than national system collections. Notwithstanding CGIAR’s mandate to conserve this germplasm and to supply its materials to users globally, CGIAR centres have strong regional foci that have skewed their geographic distributions in the past. And although CIAT and ILRI have been expanding their regional foci (e.g. ILRI research on breeding for disease resistance and greater use in Napier grass, for diversity in buffel grass and for both diversity and dual-purpose food-feed roles in cowpea and other legumes), the combined resources of all CGIAR centres probably do not include the technical skills that would enable them to cover the full range of priorities and needs in tropical forage work. Greater collaboration and efficiency should provide a more comprehensive and unified strategic position for the CGIAR.
9 Forage treaties and agreements are inadequate
The great majority of the world’s tropical and subtropical forage resources are not listed in Annex 1 of the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA). The CGIAR collections are managed under Article 15 of this treaty and may be made available under standard material transfer agreements. The exchange of material from national collections can be constrained by a reluctance of countries to share their germplasm with others outside of the multilateral ITPGRFA agreement. In addition, the vast majority of tropical and subtropical forage germplasm that has been collected was collected before the Convention on Biological Diversity came into effect in 1994, meaning that most forage germplasm held outside of the CGIAR genebanks can in fact be exchanged without attending to treaty obligations. This is an important issue for forage conservation, but possibly more so for utilization. A strategy taking all this into consideration needs to be developed.
Read the whole of the new strategy: A global strategy for the conservation and utilisation of tropical and subtropical forage genetic resources, by Bruce Pengelly, Pengelly Consultancy Pty Ltd., Dec 2015.