David Wood, in his "Why I believe gene banks are a waste of money" on the nature and importance of conserving the diversity of our crops ( THES , March 14), argues that the Global Conservation Trust duplicates existing mechanisms but does not say what they are.

The campaign to establish the trust is being conducted by Food and Agricultural Organisation of the United Nations and the International Agricultural Research Centres precisely because there are no satisfactory mechanisms to guarantee the long-term conservation of crop resources.

International collections attempt to conserve critical crop diversity on ever-shrinking annual budgets. National and regional collections in many developing countries are even more challenged, as the modest annual budgets for conservation, regeneration and curation of resources of long-term value are easily dropped in the face of short-term financial problems.

The idea that a few countries, or a repository in arctic permafrost, will store and make readily available the crop diversity of benefit to farming communities around the world has simply not proven popular or practical.

ÖйúAƬ

What is new about the Global Conservation Trust is that it is an endowment aimed at generating an annual income. This can ensure the maintenance of many existing national and international collections in perpetuity, free from the unpredictability of serial short-term funding.

It is true that useful genetic traits from many crop lines have been built into our portfolio of crops. But the advantages of focusing production on ever-fewer crop varieties, bred for maximal productivity, needs to be balanced by a commitment to maintain the diversity needed to face future changes in agricultural practices, consumer demand, climate changes, pests and diseases. We may not know now what those desirable traits will be, but we need to make sure they are available to innovative farmers and to scientists.

ÖйúAƬ

Jeff Waage
Head of agricultural sciences
Imperial College London