Prólogo

SOLONESKI, S.; LARRAMENDY, M L

Herbicides, Theory and Applications

INTECH

Lugar: Vienna; Año: 2011; p. 1 - 2

Weeds have always represented one of the main limiting factors in crop production. For the first time in human history, we are technically able to produce as much food as needed for the ever increasing world population, thus theoretically eliminating the risk of famine. These are mainly observed in cases of wars and poor management. Herbicides have revolutionized weed control worldwide. Since weeds are responsible for a loss of over 14% of global harvests, they have been rapidly adopted worldwide. This is no small concern, since most of the largest producers of commodities are located in the so called developing world or emerging economies. The popularity of these chemicals derives from the fact that they are the most reliable and least expensive method of weed control available today. Weeds are different from other pests in crop production because they are relatively constant, while outbreaks of insects and disease pathogens are sporadic. Apart from quantitative damages caused by weeds due to competition for nutrients, light and water, they are able to cause indirect qualitative damages due to crop yield reduction, contamination of seeds, harvesting practices, and soil degradation. In the past 60 years, agrochemical companies have successfully discovered and marketed a wide array of selective herbicides. Their success is largely responsible for the abundant and sustained food production demanded by national governments. The use of herbicides has simplified crop management attempting to keep weed population at acceptable levels. Herbicides and other agrochemicals have provided, year after year, tools to grow the most profitable crops on the same fields. Thus, reliance upon herbicides as the primary method of weed control in crop management systems is understandable. Unfortunately, they are not free from posing serious environmental risks and substantial health dangers to the population. Residues on food, groundwater contamination, as well as occupational exposure to farm workers are not to be disregarded. In our industrialized society, the common feeling about herbicides is oft en indifference. In agreement with this concept, several surveys carried out by herbicides manufacturers claim that less than 10% of the interviewed consider herbicides dangerous for man and the environment. This social acceptance is most probably due to the communication gap existing between the scientific community and society. Misinformation and disinformation are also to be included in this context. Society is not usually fully aware of ?the price? to be paid in order to provide an abundant and uninterrupted food production chain. Before registration of a new herbicide, rigorous testing is mandatory, surfactants and inert ingredients present in commercial formulations are included as well. These tests include animal toxicity, namely acute toxicity, carcinogenicity and teratogenicity bioassays, effects on non-target organisms, and different modes of environmental degradation. Several excellent papers within the complex herbicide field came out in the last decade. A simple search in a databank as PubMed, displays more than 3,500 reports published in scientific journals only during 2010. As developments in this field have been quite rapid, we believe the writing of a new book scoping the subject is fully justified. To tackle among others, related geopolitical, economical and population issues in our modern, internet-economy connected societies, we aim to present a more holistic approach of the matter, in order to appreciate the full scope of the question. The content selected in Herbicides, Theory and Applications is intended to provide researchers, producers and consumers of herbicides an overview of the latest scientific achievements. Although we are dealing with many diverse and different topics, we have tried to compile this ?raw material? into three major parts in search of clarity and order. First, in Weed Control and Crop Management, readers will find twelve chapters with background information about the effects of herbicides on the undesired plants that grow and reproduce aggressively in crops as well as their management and several empirical methodologies for study. Second, in Analytical Techniques of Herbicide Detection, we have included seven chapters dealing with specific analytical procedures used to identify, quantify and characterize different types of herbicides. Finally, Herbicide Toxicity and Further Applications encloses eight chapters related to the usage of conventional and non-conventional cellular bioassays for estimating herbicide toxicity as well as the putative indications of these agrochemicals as antiparasitic compounds outside their classical, recognized herbicide use. Many researchers have contributed to the publication of this book. Given the fast pace of new scientific publications shedding light on the matter, this book will probably be outdated very soon. We regard this as a positive and healthy fact. The editors hope that this book will continue to meet the expectations and needs of all interested in the methodology of use of herbicides, weed control as well as problems related to their use, abuse and misuse.