Appreciation

Ann. uppl. Biol. (1990), 117, 233-235 Printed in Great Britain

An Appreciation

Charles Potter, D.Sc, D.I.C., F.I.Bio1, F.R.E.S. 1907-1989 President of the Association of Applied Biologists 1960-1961

Member of Council 1941-1943, 1955-1957 Elected Honorary Member, 1974

Charles Potter (“C.P.” to his associates) was a remarkable and gifted applied biologist who inspired both great affection and great respect from his colleagues and friends. His achievements were outstanding and highly influential, but due to his modest manner and because they were in many cases realised and expressed through the work of others, his contribution was probably only fully appreciated by those who had the privilege to be associated closely with him.

His career was marked by a continuing series of seminal insights into the requirements for making pest control more effective and safer. His own personal research began at Imperial College with which he maintained close contact throughout his long working life. Even from that earliest work on stored products pests, some of the hallmarks of his later approach to research can be seen. For example, he began to work on the residual activity of pyrethrum insecticides which were to feature so prominently in his interests. Also in this early work he recognised the need to tackle together the many factors which determine pesticide activity, with the associated requirement for precise bio-assay techniques: the accurate determination of relationships between dose and response. This led him to design apparatus for accurate dosing of sprays and residual deposits.

This quest for accurate and reproducible dosing techniques continued following his move to the Insecticides and Fungicides Department at Rothamsted Experimental Station in 1938, leading to the famous “Potter tower” which made possible very precise application of pesticide sprays to test surfaces and which became a standard experimental technique used throughout the world. This was just one, albeit prominent, example of his concern for a rigorous quantitative approach.

When Potter came to Rothamsted he joined a small team of chemists, providing them with much-needed biological expertise. The potential benefits from a synergy of different scientific disciplines were certainly not lost on him. When he succeeded Dr F. Tattersfield as Head of the Insecticides and Fungicides Department in 1947, following a year as visiting Professor at Rhode Island State University and Connecticut Experimental Station, he took full advantage of the expansion in research at Rothamsted to construct a broadly based team without rival. The research staff included entomologists, organic chemists, physical chemists, biochemists, neurophysiologists, agronomists and notably an instrument engineer, reflecting his continuing concern for improved techniques.

The research programme which he fashioned for this truly multi-disciplinary department anticipated and illuminated almost all the major issues concerning chemical methods of pest control: relationships between molecular structure and biological activity, mode of action of leading chemical insecticide groups, the nature and mechanisms of resistance to insecticides, effects of pesticides on beneficial insects, formulation and application techniques, identification and exploitation of arthropod behaviour-controlling substances, factors determining the activity of systemic pesticides, field control of important agricultural pests and diseases. It will be apparent that this programme also ranged from fundamental studies at the molecular level to field investigations of direct practical application. CP saw no artificial divisions between these different types of study and respected each equally.

234

Although CP would have been reluctant to make distinctions between projects within his department, many others would attach most importance to his long-standing championing of the work on synthetic pyrethroids which led eventually to the so-called fourth generation insecticides, the group of products which has become of such major importance in pest control. His support for this work demonstrated again essential characteristics of his approach: the requirement for precise bio-assays in structure/activity studies which enabled the effects of small changes in molecular structure to be accurately determined and interpreted; the far- sighted recognition that despite the merits of the organochlorine, organophosphorus and carbamate insecticides which were then dominant. they had certain limitations such as inappropriate persistence or inadequate selectivity. In contrast, the pyrethroids offered the prospect of high potency to insects coupled with very low toxicity to mammals. For these various reasons he maintained a steadfast support for research on the synthetic pyrethroids over a period of many years, despite scepticism by others including some in official circles. The justification for his optimism is now plain to see. The achievements of the team he directed for so long were recognised in the award of the UNESCO prize.

If he had had to choose, the other line of work he would probably have selected from the wide range of research at Rothamsted would have been that on the genetics and mechanisms of resistance to insecticides. He saw resistance as the greatest long term threat to chemical control and it was a matter of great satisfaction to him that the work in his department contributed materially to strategies for deferring its onset or avoiding it altogether.

After a long and fruitful period directing research, on his retirement from the post at Rothamsted in 1972, CP returned to a more active involvement in the practice of research when he was appointed as a consultant to the Technical Director of the Wellcome Foundation Research Station at Berkhamsted. In this role he was able to combine the advice and wise judgement derived from his long experience with active experimental work at the bench. He took the leading part in again establishing a multi-disciplinary group, unusual for a commercial concern, investigating fundamental biochemical and physiological aspects of insecticide mode of action and resistance with the objective of more rational insecticide design. This indian summer in his research career represented a further productive period in developing understanding of pesticide action.

CP’s approach to pesticide research was based on a profoundly thoughtful analysis of the key issues - not only from the scientific standpoint, but also in relation to societal needs for improved crop production and reduced hazard. Coupled with his integrity and independence, these qualities made his advice on policy matters particularly valuable. He saw it as a responsibility to contribute to official bodies and played his full part in maintaining the infrastructure of his subject. He was President of the Association of Applied Biologists in 1960-1961 and a Vice-president of the Royal Entomological Society. He did not, however, relish administration and certainly not the politics of science. This last characteristic may not have promoted his personal advancement, but certainly helped to endear him to the many who worked closely with him.

This high regard was enhanced by other very human qualities. CP was an inveterate tinkerer with cars. In the time when official working hours still required attendance on 6 days a week, the Saturday morning coffee break in the Department at Rothamsted frequently slipped into an extended car maintenance club with CP as the guiding spirit. He was also a tennis devotee and keen player, renowned for a devastating lob which proved especially irritating to his more aggressive opponents.

His many friends will treasure such affectionate memories of him. We have lost a great gentleman and mentor. But he will have an enduring memorial through his scientific achievements and the lasting influence he had on those who worked under his aegis. They will have learnt from him the traditional values of science, the painstaking pursuit of

235

knowledge, the rigorous objective testing of concepts, sometimes frustrating to more impatient younger colleagues, but in the long term the route to real advance. His approach to research management was a simple one: to suggest an area for investigation, to allow his staff freedom to explore it, providing guidance through searching questions and openness to discussions. It is a style different from the modern fashion for highly “accountable” and “goal oriented” research requiring frequent appraisal and monitoring. But in view of the results, who can question its effectiveness?

I.J. Graham-Bryce