A crop protection
meeting to celebrate 50 years of the Pest Management Group
Adme for Ag - Predicting and Designing Physicochemical
Properties for Crop Protection Agents, London, 2 December
 One
of the crucial aspects of designing an effective crop protection
agent is to ensure that it has the required properties to
reach its site of action. Whether the final product is used
to treat the seeds, sprayed onto the ground or onto the foliage,
it has to enter the plant, travel to its site of action and
then remain there long enough to bring about its effect. There
are many barriers to this process and effective enzyme inhibitors
never reach the market because of them.
However it is also important to model the loss of compounds
into the environment. Volatility allows distribution within
the crop canopy and between soil particles and thereby improves
coverage. But if a compound is too volatile, it will be too
easily lost from its application point, leading to poor control
of the target and pollution some distance from its point of
application. Can volatility be modelled? Yes it can. Leaching
is, perhaps, a more important source of environmental contamination.
Applied compounds can be moved through soil profiles and enter
water catchment areas. Are the physicochemical properties
that increase or reduce the probability of compounds leaching
known? Can the performance of a compound in the field be predicted?
Is the persistence of these compounds important in cases of
leaching? The answer to all these questions is yes and it
is possible to model for high mammalian toxicity.
Geoff Briggs has played a seminal role in introducing the
importance of physicochemical properties to the distribution
of molecules in plants, insects, fungi and soils. His unique
contribution has been to work with discovery scientists to
influence their synthesis programmes. In several organisations,
he has worked as ‘one-stop-shop’ consultancy to
large groups of chemists.
The secret of his remarkable success is that he has the patience
and persistence to make him an effective part of the team.
He gains ready acceptance with his wicked sense of humour
and affable, easy-going manner. None who have worked with
him can forget his approach to estimation of partition coefficients
by his BOFP (back of a fag packet) calculations, or indeed
his graphic 'plumbers' guides to plant physiology.
We shall never forget seeing Geoff on one Monday before the
BCPC Conference holding the Conference Proceedings open at
the entry for a new sulfonylurea herbicide. He looked worried
and pointed at the structure saying it was a 'ground-water
candidate' - it would leach and persist. He explained his
reasoning based upon the compound's chemistry. Time proved
him to be correct.
His recognition of the power of approximation, coupled with
a sound knowledge of chemical principles, has been key to
making solid progress in highly complex areas. He has prevented
significant effort (and research funds) from being wasted
on the synthesis of poor candidates, thus assisting the chemist
in concentrating upon useful chemical space. Every effective
discovery regime now embraces his philosophy and he can be
pleased to reflect upon the degree of progress that he has
catalysed over the past years.
The meeting Adme
for Ag - Predicting and Designing Physicochemical Properties
for Crop Protection Agents has been organised as a tribute
to Geoff and as a celebration of 50 years of the Pest Management
Group. The Group developed from a Panel of the Agriculture
Group in 1954, becoming the Pesticides Group, which became
intimately associated with the learned journal Pesticide Science;
this association continues to this day. Since 1954, the Group
has developed its remit and changed its name, becoming the
Pest Management Group five years ago. The reasons for the
change are many, but it was surely driven by the recognition
of the need to remain close to the journal, which had become
Pest Management Science.
The meeting includes contributions from distinguished experts
in the field examining what is known about moving a compound
from the sprayer to its binding site and the design of such
compounds, while preventing damage to the environment. It
will appeal to all who work with bioactive compounds that
need to be transported within a living system to be effective.
For the many friends and colleagues of Geoff, it will also
be a cogent reminder of the significant recent progress in
this field, which has moved its reputation from a ‘black
art’ to a seminal contribution to plant science.
Book
online for this event or contact conferences@soci.org.
By Len Copping and David Evans
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