BSPP News 30 Spring 1997 - Online Edition

The Newsletter of the British Society for Plant Pathology
Number 30, Spring 1997

Perspective on Pathology

Diversity is the Spice of Life

One impact of the 1947 Agriculture Act - more research, more food - was thatI didn't have to look for a job. The expansion of the Plant Breeding Institute(aided by Richard Macer) easily made room for me - and later for my two otherex-Presidential friends and colleagues, Roy Johnson and Peter Scott.

We enjoyed exciting days, helping to provide some of the tools for aphenomenal increase in agricultural production. However, we did begin torecognise some, but certainly not all, of the danger signs of this mammothenvironmental change - I remember, for example, long discussions on the wisdomor otherwise of the 1964 Seeds Act, designed to protect the breeder and toprovide royalties. Now we see one of the consequences of commercialised breedingwithin an industrial ised agriculture: massive monoculture and the acceleratingerosion of genetic resources.

Monoculture and mixtures

Some of the work that I have been involved in, particularly in Zürich,helped to reveal one effect of this trend. Monoculture of cereal varieties, and,even more so, of disease resistance genes, has led to the selection of atrans-national pathogen population; distinct "islands" of the pathogenpopulation, separated because of the previous relatively small and diverse hostpopulations, simply disappeared. The pressures from such massive inter-linkingof pathogen populations helped rapidly to wipe out the effectiveness of manyresistance genes.

One simple alternative that John Barrett and I tried to push, in the teethof accelerating industrial agriculture, was the use of variety mixtures. After abrilliant but short-lived beginning, it failed in Britain. But I am stillpushing this approach, because, properly done, it is simple, cheap, effective,reliable, stable, requires no inputs and has shown great effectivenesselsewhere. Aha, I can almost hear the cries from some quarters - here comesBio-Wolfe again with his tired old mixtures. However, I tend to follow MaxPlanck's cynical conclusion - "a new scientific truth does not triumph byconvincing its opponents and making them see the light; but rather because itsopponents eventually die and a new generation grows up that is familiar with it"(Fisher, 1978).

Genetic engineering

What is being offered to deal with such side-effects of monoculture?Breeding and pesticides, of course, but today, in addition, we have the prospectof genetic engineering. Now, all scientists agree that molecular biology isamazing for the new insights that it gives us into the structure of livingorganisms. And it provides the most excellent tools for biological research -indeed, I look back with great pleasure to the way in which Dick Flavellpersuaded us to be among the first to use those tools for our populationstudies.

But genetic engineering as it is applied to plant breeding in its modernbusiness framework is, in my opinion, just not acceptable. Why? Because many ofthe characters currently available have only dubious relevance to agriculture(there's always jam tomorrow), and all are being pushed in ways that promotemonoculture still further, to the detriment of agricultural systems and theenvironment. Moreover, the entry of the products of genetic engineering into themarket seems now to be moving beyond the control of our democratically electedrepresentatives. Because of the high costs of investment, and thus the need fora large and rapid return, it seems doubtful to me, whether genetic engineeringwill ever be able to contribute sensibly to agriculture; certainly not in theforeseeable future.

Fortunately, there are other ways. For example, the use of materials derivedfrom genetic engineering has been banned, worldwide, by the organic agriculturemovement. This may seem an extreme position to some, but it does offer a democratic alternative. Indeed, for this and for many other reasons, I havegradually come to the conclusion that organic systems are the only way toencourage a sound way forward in agriculture.

Organic farming and plant breeding

Of course, there are problems. For example, by eschewing geneticengineering, the organic movement may eventually cut itself off from all newvarieties developed from mainstream breeding as genetic constructs spread amongthese programmes. This means that breeding programmes directed primarily toorganic production need to be extended and strength ened. If this can be done(funding?), there could be many advantages - for (almost) the first time,breeding would be carried out under organic conditions selecting for charactersof prime importance to organic agriculture. We might also see the development ofmethodologies that are now closed to conventional breeding (e.g. populationbreeding and selection for mixed cropping) and a wider range of crops underconsideration.

I believe that we are now at a crossroads. On the one hand, if we follow thedirection of mainstream agriculture towards even more intensification andmonoculture (e.g. through genetic engineering), can we provide enough food notonly now, but forever more? Based on current performance, I have serious doubts.On the other hand, can an organic approach do the job? Better sustainability isbeyond doubt, but the principal criticism from the mainstream is that a majorshift to organic production will mean reductions in yield and an inability toprovide enough food.

I believe this to be wrong, on at least three counts. First, in a paper tothe Farm and Food Society in 1995, Lawrence Woodward stated ". . . that thequestion of feeding the world organically has less to do with the technicalability of organic farming to produce adequate nutrients and is more aboutsystems of distribution, markets, finance and political structures".Second, when I look at that technical ability of organic farming to produce, Ifind that overall output from an organic enterprise, and particularly from asmall and intensively managed unit, is already high.

Thirdly, and most importantly, we need to compare the returns (whatreturns?) on the immense amount of funding that has gone into molecular-basedagricultural research and compare them with the returns that could have accruedfrom investing that money in organic research in an environmentally-sensitiveframework. One such investment that I am personally in the process of making,albeit on a small scale, is to try to maximise the use of functional diversityin a range of organic agroforestry systems, in Suffolk. The objective is tothrow monoculture completely into reverse and to maximise the positiveinteractions that can occur among trees, crops and naturally occurring plants,animals and microorganisms. Further considerations here are the extent to whichsuch systems might contribute to an increase in rural employment - and toputting some of the culture back into agriculture.

My only problem is that, to follow my 80 year tree rotation, I need to findsome way of staying around for a long time . . . gene therapy . . . ?

Martin Wolfe
Federal Polytechnic Institute, Z├╝rich, Switzerland