Introduction to Fungi, Third Edition

OTHER MEMBERS OF THE PUCCINIACEAE
633
British Empire in which coffee drinking was
fashionable. Initial outbreaks of the rust were
not taken seriously because severe infections,
which led to the defoliation of trees, showed
their effect only in subsequent seasons in the
shape of a gradual debilitation of the coffee
plants (see Brown et al., 1995). After the failure
of several successive crops, H. Marshall Ward
was sent to Ceylon in 1879 to investigate the
problem, and he succeeded in elucidating the life
cycle of H. vastatrix and the details of the
infection process (Ward, 1882). Unfortunately,
by that time it was too late to save the coffee
production of Ceylon and other South East Asian
countries to which the rust had spread in the
meantime. As a consequence of coffee rust, tea
became the main crop of Ceylon, and tea
drinking was promoted throughout the Empire
(Schuman, 1991).
The spread of coffee rust to all major coffeegrowing
regions of the world (except Hawaii) is
charted in Fig. 22.14. It is probably the combined
result of human travel and natural long-distance
transport. The much-dreaded jump from West
Africa, where the disease arrived in the 1960s, to
Brazil probably occurred during a period between
January and April in the late 1960s as a one-off
transport of urediniospores by wind (Bowden
et al., 1971). A similar chance event of wind-borne
intercontinental rust spore traffic may have
happened in June 1978 when the sugarcane rust
(Puccinia melanocephala) arrived in the Dominican
Republic, probably from Cameroon (Purdy et al.,
1985; Brown & Hovmøller, 2002). Within coffee
plantations, urediniospores of H. vastatrix may be
spread both by wind and by rain splash.
Coffee rust can be controlled by fungicide
applications, with copper-containing compounds
being the most useful even today (Bock, 1962;
Kushalappa & Eskes, 1989). Since the timing of
fungicide application is crucial, disease forecast
models to optimize fungicide applications are
being developed. Resistance breeding is also
promising. The main cultivated coffee plant,
Coffea arabica, was clonally propagated by the
Dutch in the late seventeenth century and is
therefore genetically quite uniform across many
coffee-growing areas, but the introduction of
Fig 22.14 The journey of coffee rust (Hemileia vastatrix)
aroundtheworld.Timepointsoffirstrecordsareindicated.
Redrawn from Schuman (1991), with supplementary data from
Monaco (1977) and Schieber and Zentmyer (1984).