Controlling apple diseases_ 7th International Congress of Plant Pathology, Edinburgh, August 1998 (AP97030)

This is a final research report from Hort Innovation’s historical archives. Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.

What was it all about?

In August 1998 the 7th International Congress of Plant Pathology was held in Edinburgh. The congress was attended by over 2000 delegates from all branches of the plant pathology discipline, from all parts of the world. Additionally, researchers at the East Malling Research Station of Horticulture Research International, in Kent, United Kingdom were also visited.

The Congress covered all aspects of plant pathology, with a strong emphasis on molecular biology. This was an emerging area of science which, in the not too distant future, was considered likely to provide breaktroughs in plant disease resistance, in the development of fungicides with modes of action which were carefully designed, and would become a significant factor in the identification and classification of pathogens and other organisms. Molecular techniques were also developed for use in detecting the presence of pathogens in epidemiological studies.

Approximately forty papers were presented which dealt directly with the diseases of pome fruits, and a further sixty which dealt with diseases of other crops where the information involved was applicable to pome fruit.

The principal issue in plant protection of pome fruit, as I see it, was the need to develop an 'assured produce' scheme along the lines of that established in the United Kingdom. This involved the documentation of the whole production process so that it could be demonstrated that apples and pears were grown in a responsible manner with reference both to consumer safety and to the environment. This scheme would be based on, amongst other things, integrated fruit production where the consequences of all actions and their inter-relationship were taken into account. The majority of this work was based on existing knowledge, with research undertaken to fill any gaps.

There was a general trend seen as the need to reduce pesticide usage, however there did not appear to be an overall acceptable pesticide use measurement system. A reduction on the reliance on conventional fungicides was considered likely, in the long term, to be reduced by the development of transgenic cultivars with resistance to disease. In the short term the potential undesirable effects of fungicide was overcome by a switch to fungicides with wide spectrum of activity and high efficacy, low toxicity and environmental concerns, which were based on analogues of antifungal compounds from nature. In the medium term the development of 'specific acquired resistance inducers', which had no effect on the plant but assisted the plant in resisting disease, would provide disease control with a reduced fungicide input.

Whilst the Congress was attended by scientists with various interests, the strong involvement in molecular technology, was to some extent, at the expense of interest in more traditional areas of epidemiology and practical disease control. It was of concern that whilst there was a trend developing worldwide for the discovery of many exciting areas of disease control, there may have been a lack of scientists with the interest to take these developments into practical agricultural production.