Agriculture Reference
In-Depth Information
Chapter 14
Controlling plant disease using biological
and environmentally friendly approaches:
making it work in practice
Dale Walters
Scottish Agricultural College, Edinburgh, UK
14.1
Introduction
Since the 1960s, aggregate world food production has increased by 145%, with production
increasing by 280% in Asia, nearly 200% in Latin America and 140% in Africa. Food
production started from a higher base in industrialised countries, although it still grew by
68% in Western Europe (FAO, 2005; Pretty, 2008). During this period, world population
doubled to more than six billion, although
per capita
agricultural production has exceeded
population growth, with the result that for each person there is an additional 25% more
food today compared to the 1960s (Hazell & Wood, 2008; Pretty, 2008). Despite these
increases in productivity, there are still some 800 million people hungry, with inadequate
access to food (Pretty, 2008). In the United States in 2004, 38.2 million people, includ-
ing 13.9 million children, lived in food-insecure households (Nord
et al.
,
2005), while in
India in 2004, many people went hungry despite bumper harvests (Thurow & Solomon,
2004). The problem is of income distribution rather than food shortages - the hungry are
too poor to buy the food (Hazell & Wood, 2008).
Increases in food production in the past 50 years have resulted from increasing the
intensity of production on agricultural land, with increased use of machinery, fertilisers
and pesticides. Indeed, the use of pesticides in agriculture has increased hugely, now
amounting to some 2.56 billion kg yr
−1
(Hazell & Wood, 2008; Pretty, 2008). However,
the ineffi cient use of these inputs has resulted in considerable damage to the environment,
with increased agricultural area contributing greatly to the loss of habitats and biodiver-
sity (MEA, 2005; Scherr & McNeely, 2008). Interest in the sustainability of agricultural
systems arose out of concern for the damaging effects of agricultural practices on the
environment that began to surface in the 1950s-1960s (Pretty, 2008). Current concerns
about sustainability revolve around the need to develop agricultural technologies and
practices that: (a) have no adverse effects on the environment, (b) are effective and can
be easily accessed by farmers, and (c) lead to increased food productivity, while yielding
positive effects on environmental goods and services (Pretty, 2008). The key principles for
sustainability are to integrate biological and ecological processes (e.g. nutrient cycling,
soil regeneration, predation and parasitism) into food production processes, minimise use
