Agriculture Reference
In-Depth Information
Chapter 3
Biological control agents in plant
disease control
John M. Whipps
1
and Mark P. McQuilken
2
1
Warwick HRI, University of Warwick, Wellesbourne, Warwick, UK
2
The Scottish Agricultural College, Ayr, UK
3.1
Introduction
Over the last 50 years, disease control has relied heavily on the use of chemical fungicides,
bacteriocides and soil fumigants. However, there are now many problems associated with
their continued deployment including increasing pressure to reduce chemical use in the
environment in general, development of pesticide resistance in many pathogens, and
decreasing availability of active ingredients through stricter registration and diffi culty in
fi nding novel active compounds. Consequently, the search for alternative non-chemical
methods of disease control continues to gain signifi cance. Indeed, for organic growers
where chemical control measures are not permitted, these considerations have been para-
mount for many years.
In the broadest sense, alternative, biologically based disease control measures have
been used for many years. These include plant breeding for resistance, crop rota-
tions, tillage systems and fertilizer practices that affect pathogens directly or alter
microbial populations to inhibit pathogens, exploitation of disease suppressive soils
and growing media, as well as environmental controls, particularly in the glasshouse.
However, the greatest interest has been in the development of biological control agents
(BCAs) used as microbial inoculants, mimicking the use of chemical pesticides. Many
aspects of the understanding, development and use of BCAs have been reviewed
extensively in the last 10 years (e.g. Whipps, 1997a, 2001, 2004; Whipps & Davies,
2000; Montesinos, 2003; Harman
et al
., 2004; Kiss
et al.,
2004; Kloepper
et al
., 2004;
Compant
et al
., 2005a; Fravel, 2005; Haas & Défago, 2005; Jacobsen, 2006; Harman,
2006; Woo
et al
., 2006; Bakker
et al
., 2007; Lugtenberg & Leveau, 2007; Whipps &
Gerhardson, 2007; Weller, 2007) to which reference should be made for detailed
background information. This chapter uses selected examples to focus on some key
areas of importance or where advances have taken place relatively recently. It also
attempts to indicate future directions that will enhance the development and commercial
marketing of BCAs.
