From February 24 -28, 1992 an international symposium on Durability of
Disease Resistance was held at the International Agricultural Centre in
Wageningen, the Netherlands. The symposium, organized by the Department
of Plant Breeding of Wageningen Agricultural University and the Centre
for Plant Breeding and Repro- duction Research, CPRO-DLO, was part of
the DGIS funded programme Durable Resistance in Developing Countries.
Without any form of prevention or protection nearly all crops will be
seriously or even severely damaged by a range of pathogens. In modern
agriculture man has been able to control many if not most pathogens
using i) pesticides, ii) phyto- sanitary methods such as control of seed
and plant material in order to start a crop disease free, iii) agronomic
measures such as crop rotation, iv) disease resis- tance or combinations
of these measures. Over the years the use of pesticides has increased
enormously and so did the pro- blems associated with pesticide use, such
as environmental pollution and building of resistance and tolerance to
these pesticides in the pathogens. The use of resis- tance too increased
strongly over the years and here too problems arose.