342 Produce Degradation: Reaction Pathways and their Prevention
11.1 INTRODUCTION
Produce, and crop plants in general, can be attacked by numerous pests, mainly
insects, nematodes, and fungi. Moreover, various weeds may compete with the crop
plants for moisture, nutrients, and light. Ever since the dawn of agriculture, human-
kind has constantly struggled with pests and weeds to increase crop yields and
provide an adequate supply of food. The idea of combating them using chemicals
can be traced back to ancient Greece and Rome, where burning sulfur helped to
avert diseases and insects. Other examples can be found throughout history [1,2].
However, it was not until the 20th century when the era of mass-produced and
applied synthetic organic pesticides began and chemical pest control became an
integral part of modern agriculture that we were able to sustain a rapidly growing
world population with land capacity to spare.
Nevertheless, every coin has two sides, and the use of pesticides is also associated
with certain risks. Real and perceived concerns about the impact of pesticides on
human health and the environment have led to strict regulation of their application
and pesticide residue levels in food and water supplies. These concerns are also
reflected in the development of new pesticides and more effective ways of applying
them with the aim of lowering their risks and tipping the balance in favor of their
benefits. At the same time, scientists seek alternative approaches to chemical pest
control, but their potential risks also need to be properly evaluated.
The main part of this chapter discusses the positive role of different groups of
pesticides in produce production, preservation, quality, and safety. To make the
picture complete, potential risks associated with pesticide use and strategies to reduce
them are also briefly discussed at the end of the chapter.
11.2 POSITIVE IMPACTS OF PESTICIDE USE
IN PRODUCE PRODUCTIONThe scope of the term pesticide is very well expressed in this internationally adopted
definition by the Food and Agriculture Organization (FAO) of the United Nations:
Pesticide means any substance or mixture of substances intended for preventing,
destroying, attracting, repelling or controlling any pest including unwanted species of
plants or animals during the production, storage, transport, distribution and processing
of food, agricultural commodities, or animal feeds or which may be administered to
animals for the control of ectoparasites. The term includes substances intended for use
as a plant growth regulator, defoliant, desiccant, fruit thinning agent, or sprouting inhibitor
and substances applied to crops either before or after transport. The term normally excludes
fertilizers, plant and animals nutrients, food additives and animal drugs.Table 11.1 lists significant pesticide groups together with the pests they combat
and/or problems they address in produce production. There are numerous sources
of information on the properties, biological effects, modes of action, applications,
toxicology, regulation, and monitoring of pesticides in the scientific literature, and
recently the Internet has become a valuable and easily accessible tool. For instance,
the Web site of the U.S. Department of Agriculture (USDA) National Agricultural