Pesticides have undoubtedly helped to increase agricultural production and control vectors of disease over the last five decades, but there has been increasing criticism since Rachel Carson alerted users to the side effects of some pesticides in the environment. My own involvement dates back to before Rachel Carson’s book Silent Spring as I was with a team of entomologists seeking to control insect pests of cotton in Africa. We recognised then that pesticides should only be used in conjunction with other control tactics, a system recognised in the USA and much publicised as integrated pest management. In the UK authorities had also responded to early problems due to use of highly toxic pesticides and the adverse effects of birds due to organochlorine insecticides by establishing the voluntary Pesticides Safety Precaution Scheme. While developed countries introduced registration of pesticides, requiring detailed scientific data on which to base a risk analysis, many other countries did not have the resources needed to operate a detailed registration system. In consequence highly toxic pesticides have been used in many countries, especially in tropical areas where protective clothing, as used in temperate climates, is unacceptably hot and uncomfortable to wear. This has led to many cases of illness and death following exposure to these highly toxic pesticides. These problems have been increasingly recognised and efforts made to harmonise registration requirements. This book sets out to emphasise that apart from correct choice of pesticide, it is the way it is applied that impacts on people, either directly on those using the many commercial products, but also others by the movement of pesticides in the environment and as residues in harvested produce.

Application technology has largely been ignored, and it has been left to engineers to design machinery that is easy to use and is as inexpensive as possible for the user. It is, however, a complex multidisciplinary subject which affects us all. Following the previous book, Pesticide Application Methods, that dealt with the different equipment that can be used, this book explains how the registration process can avoid use of the pesticides that pose a significant risk to users and the environment, and how by a better understanding of the subsequent movement of pesticides following application, the risk of any adverse impact following their use can be minimised. Today carefully applied pesticides, used only when needed, can contribute to higher productivity and allow us to feed and protect the growing human population. This requires much better education and practical training with certification so that pesticides are indeed applied more accurately and with greater safety than in the past. It is hoped that this compilation of data will help readers to have a better understanding of how pesticides can be applied without harming the users and adverse pollution of their environment. In addition, the overall management of pesticides, covering packaging, storage and proper stock control, needs to be improved so to avoid having obsolete stocks of pesticides. Unfortunately many countries still have obsolete pesticides that need careful disposal to avoid pollution of the environment.

There is a vast amount of information that has been published in scientific journals and books, so only selected data have been used in writing the chapters. More information is now available by the Internet, both from official web sites of government agencies and agrochemical companies, but also from pressure groups. However care is needed in choosing appropriate sources of information as sometimes only part of a story is reported. As with many complex subjects these days, it is important that as holistic approach as possible is made to obtain the benefits of the technology while minimising adverse effects.