Developing New Pesticides

Press, Volume CVI, Issue 31118, 22 July 1966, Page 6

Developing New Pesticides

The intensification of land use for both agricultural and horticultural purposes makes the need for pest, disease, and weed control more important as, unchecked, plagues of various sorts could easily develop. As a result of the increased use of chemicals the balance of nature has been upset in various ways and misuse or careless handling has resulted frequently in destruction of beneficial plants and livestock, and pollution of waterways and atmosphere. Much comment for and against the use of these materials has been made, much of it biased but some of it very conclusive and damning. But what is not generally realised is the extent to which a new crop protection product is tested in its development and before marketing. Initially, during what is called the primary screening, a great number of chemicals may be tested from which only a very few will give indications to warrant expenditure on further development.

These undergo a secondary screening during which further tests on a broader range of crops are carried out Toxicological tests will give the first indications of their lethality minimum, and chemicals considered too dangerous or damaging are eliminated. Thus the number retained for further experi-

mentation is further reduced. Later, more intensive investigations involve plot tests to see their effect on infested or infected crops; their persistence in the soil and on treated plants: and also their effect on soil life. Other work is done on the side effects on living things such as man, animals and birds to see whether they are susceptible, either immediately or in delayed action.

Chemists who specialise in specific fields analyse the new chemicals to discover their optimum useful activity rate and research into residual detection and measuring.

All the toxicological information gathered up to this point is then submitted to the Ministry of Agriculture under the notification of pesticides scheme. From this point potentially useful new materials are subjected to preliminary exploratory field evaluation for one year, followed by full scale trials during the second year.

At the same time it is further assessed for its possible dangers to man and other living things in the form of residues, and regulations regarding its safe use are formulated if deemed necessary.

In conjunction with its development, production methods and associated factors are decided.

At the completion of still further trials, which are run in collaboration with various national research organisations and the like, the product is submitted to tt>e Ministry of Agriculture for biological testing before official approval being granted. After the Ministry of Agriculture’s advisory committee’s recommendations have been received and complied with, test marketing is begun on a limited scale before the product is finally offered on the open market. Usually five years have elapsed from the time a chemical’s usefulness has been conceived until it is put on sale, and during this time an estimated £1 million to £2 million may have gone into its development. Today every chemical put on sale must carry detailed instructions on its use and contents, and it is the user’s obligation to acquaint himself with all its properties. Misuse is all too common and can so easily be avoided by following the directives given. Chemicals should always be kept in safe places, either in their original containers or easily recognisable ones. Do not keep them in the house, and ensure that children cannot get at them. When a material has been used up put the receptacle in the rubbish tin, or destroy it.