Document(s) 2 of 9

Part 1

THE ISSUE

Mega-crops and genetic erosion

The sign beside the highway in rural Canada reads "If you ate today thank a farmer." Perhaps it should also say "thank a plant breeder," because most people in the North -- as well as a large percentage of those in the South -- eat today thanks to the remarkable advances in agricultural science and technology.

It is agricultural science that has enabled us to defy the pessimistic projections of Malthus and continue to feed an ever-increasing world population. Although the rate of increase has slowed in the past generation, the tide of humanity continues to rise: today 6 billion, soon 8 billion, perhaps as many as 10 billion by the year 2050. But here is a disconcerting fact: as the human population continues to expand, the number of crops on which most of us depend for sustenance is shrinking.

No one knows exactly how agriculture began 8 000 to 10 000 years ago; how our ancestors first began to identify, manipulate, and manage certain wild plants and creatures as a source of food. We do know that the invention of agriculture represented a sea change in the evolution of humanity leading to the social systems and structures that we call "civilization."

Over the millennia, the processes of farmer experimentation led to the domestication of an ever wider range of plants to meet specific needs, preferences, and environmental conditions. The result was thousands of different and genetically unique plant varieties cultivated in farming systems. Yet today only about 150 plant species are cultivated. Twelve of these provide three-quarters of the world's plant-based food, while fully half the world's plant-based food supply comes from a limited number of varieties of just a few plant species. These are the "mega-crops": rice, wheat, maize, as well as sorghum and millet, potatoes, and sweet potatoes.

Mega-crops -- the high-yielding, high-input plants developed by scientists at the international agricultural research centres (IARCs) around the world. These were the foundation of what became known as the Green Revolution, which expanded agricultural output exponentially in many developing regions and provided food for hundreds of millions of people.

Yet at the heart of this success lies a threat. The top-down system of agricultural research, where farmers are seen merely as recipients of research rather than as participants in it, has contributed to an increased dependence on a relatively few plant varieties. This trend and the increasing industrialization of agriculture are key factors in what can only be called "genetic erosion." The term refers to both the loss of species and the reduction of variety, and it includes not only plants but also animals and microorganisms, as well as the gradual breakdown of the processes that maintain the evolution of diversity. These processes include the constantly evolving knowledge, innovations, practices, and forms of organization of farmers in local and indigenous communities. The practices relating to the production, harvesting, and preparation of food are often integral to peoples' cultural identities.

Farmers' knowledge about agricultural diversity continues to be crucial in many places, but their crops and cropping systems are also under increasing pressure. The Food and Agricultural Organization of the United Nations (FAO) estimates that of the roughly quarter-of-a-million plant varieties available to agriculture, only about 7 000 -- less than 3% -- are in use today. With disuse comes neglect and, possibly, extinction.

According to the FAO, replacement of local varieties with improved or exotic varieties, or both, is the major cause of genetic erosion around the world.

Why diversity matters

Modern agriculture is like a huge inverted pyramid; it rests on a precariously narrow base. Genetic erosion could threaten the future food supply if anything should happen to reduce the effectiveness of the high-yielding varieties that we have come to depend on.

There's the first paradox: the very success of agricultural science has led to a concentration on a small number of varieties designed for intensive agriculture, and a dramatic reduction in the diversity of plant varieties available for continued agricultural research and development.

In the past, researchers have been able to depend on farmers to retain sufficient crop diversity to provide the "new" genetic material they need. Crop breeders tend to rely increasingly on a narrow set of improved varieties. Homogeneous modern agriculture threatens the source of genetic diversity, and thus threatens both local and global food security.

It must be said also that the success of the plant breeders has not been totally unblemished. High-yielding varieties are frequently also high-maintenance varieties. They usually require regular applications of fertilizer and other inputs. In other words, they do not thrive on poor soils or in adverse conditions.

These constraints effectively put such high-yielding varieties beyond the reach of millions of small-scale farmers, who cannot afford the high-priced seed and fertilizer. Worse, most of these farmers reject the plant breeders' offerings because they simply are not designed for marginal farmland -- they meet neither the farmer's needs nor local preferences.

Yet these resource-poor farmers, a large number of whom are women, produce as much as 20% of the world's food. About one-quarter of the world's population depends on these marginal lands for their food.

Farmers under these conditions typically employ mixed farming techniques, growing both grains and vegetables, raising a few chickens for eggs and meat, and, if they can afford it, keeping a few animals -- pigs, goats, a cow or two. They select and plant seed from their own crops, and they exchange seed with neighbours or family members. Seeds are sometimes given as valued gifts. For many it is a subsistence living, often subsidized by work off the farm. But in a good season there may be a surplus to take to market.

Now the second paradox: the key to increasing biological and cultural diversity may lie with these traditional, small-scale farmers. For in their struggle simply to survive on poor soils with limited resources, small farmers continue to allow plant varieties to evolve. They select plant types (rather than varieties) based on their own observations and according to their specific needs. For example, local conditions may favour a shorter, sturdier plant; or the flavour, even the colour of the end product may be important.

The result is that to a surprising extent these farmers have become custodians of diversity. Through their skills as plant breeders -- based on experience and observation rather than on scientific knowledge -- they are maintaining the genetic variation that is essential to the continued evolution and adaptation of plant genotypes. They also bring to the process a broad cultural diversity expressed through local knowledge, language, practices, and forms of organization that are equally important in conserving biodiversity.

Rethinking conventional breeding strategies means above all recognizing the key roles of farmers.

Dynamic conservation and improvement

The one-size-fits-all approach to plant breeding not only fails to meet the needs of small farmers in the developing world, it also contributes to the loss of agricultural diversity, or agrobiodiversity. The loss of agrobiodiversity in turn leads to a reduction in the capacity of agricultural ecosystems to continue producing renewable resources. It also limits the ecosystem's ability to deal with change, which leads to decreased resilience. In short, it's a downward spiral. In the words of the FAO's 1998 report on the state of the world's plant genetic resources for food and agriculture: "It may be necessary to rethink conventional breeding strategies."

Rethinking conventional breeding strategies means above all recognizing the key roles of farmers and their knowledge and social organization in the management and maintenance of agrobiodiversity. Recognizing these roles is the basis of an approach to agricultural research known as participatory plant breeding, or PPB. Simply stated, the aim of PPB is to ensure that the research undertaken is relevant to the farmers' needs. Researchers work directly with the farmers, and much of the testing takes place on the farm.

In PPB, instead of playing a supporting role in the research, the farmers are treated as partners in the undertaking. In fact, the farmers will often take the lead, sometimes combining their own seeds with the material supplied by the plant breeders. Because the farmers' varieties are well adapted to local conditions, the results are more likely to meet with approval. And when that happens, the farmers don't hesitate to start multiplying and distributing the seed. It is a dynamic process of conservation and improvement.

PPB and the in situ conservation of agrobiodiversity -- which means maintaining the diversity of plant species on farms in the habitats where they originated and continue to evolve -- are two complementary methodologies. Small farmers breed their own improved varieties simply to survive. In doing so they maintain that diversity, but they do not distinguish between conservation and development. PPB is an approach that promotes development while conserving diversity.

PPB empowers small farmers and validates the logic behind their choices. It gives the farmers a greater measure of control over their livelihood, and for those living at or near subsistence level it provides the opportunity to break out of the cycle of poverty. Perhaps no group benefits more from the PPB approach than poor rural women. It is the women who provide much of the farm labour, process and store grains and other crops, and prepare the food. Because in many places they also preserve the best seed for planting, they play a key role in managing plant genetic resources.

Here is the third paradox: the countries that are richest in genetic material are often the poorest in terms of economic wealth. Many of the crops on which the world depends today originated in what we now call the developing world -- potatoes from the Andes in Latin America, wheat from West and Central Asia, for example. Not surprisingly, the greatest genetic diversity is still to be found in these regions, as illustrated in Figure 1.

If that diversity is to be preserved for the future food security of all humanity, then ways must be found for the people of these regions, who are in effect its custodians, to finally share in the benefits. Thus PPB must also deal with the sensitive issue of farmers' rights. This is a concept that has already been adopted by many advocates of PPB and is implicit in the Convention on Biological Diversity (CBD), which calls for a fair and equitable sharing of benefits arising out of the use of genetic resources. The concept goes beyond just compensating farmers for their role in conserving and improving plant genetic resources. It extends to enabling communities to gain more control over their own biomaterials, sharing of knowledge and technology, capacity building, and access to land and markets.

Many researchers see participatory plant breeding as an essential step to securing the world's food supply.

A decade of research

There are many approaches to PPB. Some development organizations see it as a means of alleviating poverty and increasing the food supply in some of the world's poorest regions. Others promote it as a way of making research less costly and more efficient. Still others focus on issues such as farmers' rights and greater equality for women. Many researchers see it as an essential step to securing the world's food supply. Since 1992, Canada's International Development Research Centre (IDRC) has maintained a particular focus on research aimed at supporting the conservation of biodiversity. Today that focus continues through IDRC's program for the Sustainable Use of Biodiversity (SUB). Underlying this effort is a body of applied research in the fields of agriculture, fisheries, forestry, nutrition, and health supported by IDRC during the 1970s and 1980s.

This book provides a brief examination of a decade of support for research targeted directly or indirectly at the field of participatory plant breeding. The accumulated results of this research represent a body of knowledge and experience worth sharing. It begins with a review of the approach and key research questions, illustrated by brief reports on six diverse projects around the world. Next it examines accumulated project results in the light of expected outcomes. There follows a series of recommendations for future activities, based on the lessons learned over the past decade. The book concludes with a speculative look at future directions for research and policy on PPB as an integral part of a global agrobiodiversity agenda.

Figure 1. Regions of diversity of major cultivated plants (adapted from FAO 1998).

Document(s) 2 of 9