18 Towards the Standardization of Quality

Control of Fungal and Viral Biocontrol Agents

N.E. Jenkins^1 and D. Grzywacz^2

(^1) CABI Bioscience, Silwood Park, Ascot SL5 7TA, UK; (^2) Natural Resources Institute,

University of Greenwich, Chatham ME4 4TB, UK

Introduction

In promoting the adoption of microbial con-
trol agents by farmers, the reliability of the
product is a crucial issue in ensuring accep-
tance and sustained use. In this chapter, qual-
ity control of fungal and viral biocontrol
agents is discussed; we refer the reader to
Lisansky et al.(1993) for quality control of
Bacillus thuringiensisproducts. The issue of
erratic performance of fungal and viral bio-
control agents has been recognized as a signif-
icant factor in the limited successful
commercialization of these agents (Lisansky,
1997). It has been widely perceived that fungal

and viral control agents have not, to date,

achieved a level of efficacy comparable with

that of their chemical counterparts or with that

of the leading bacterial agent, B. thuringiensis.

Many of the products that have been placed

on the market have been characterized as

‘weak products with poor efficacy and ques-

tionable quality control’ (Harris, 1997).

The implementation of an effective quality

control system should be at the heart of any

programme to develop a successful microbial

control product (Shieh, 1989). However, micro-

bial control agents are unlike chemical pesti-

cides in their manufacturing requirements and

characteristics. To be effective, microbial con-

© CAB International 2003. Quality Control and Production of Biological Control Agents:
Theory and Testing Procedures (ed. J.C. van Lenteren) 247

Abstract

An essential feature of the production of all microbial control agents is an effective quality control sys-
tem. Well-defined product specifications with accompanying quality control procedures help to maxi-
mize product performance, ensure product safety, standardize manufacturing costs and reduce the risks
for supply failure, thus building user confidence. A production system that does not have a quality con-
trol system is one whose output is uncontrolled and a lack of thorough quality feedback can result in
batches of product with variable concentrations of active agent. This results in products with variable
performance, leading to control failures by users and serious loss of user confidence. Strict quality con-
trol procedures are not only essential for product consistency, but also for safety. Where quality control is
inadequate, microbial contamination of the final product is inevitable. It must be recognized that quality
control procedures can be more complex and technologically demanding than the production procedures
themselves. It is largely on the effectiveness of these control procedures that the long-term success of fun-
gal and viral products depends.