Agriculture Reference
In-Depth Information
undercontrolled conditions.Twoyears later, United Fruit investigators in
Panama successfully replicated Brandes's experiment using Gros Michel
banana plants.
73
The geographical origin of F. oxysporum is uncertain, but there is no
doubt that human activity has played a major role in spreading the patho-
gen.
74
The fungus was probably introduced to Caribbean and Central
American soils well before the export banana boom. Observers in British
Guyana, Cuba, and Surinam reported that the apple and silk banana vari-
eties—introduced to the West Indies prior to 1750—displayed Panama
disease-like symptoms prior to the expansion of Gros Michel monocul-
tures.
75
The disease also affected non-export banana varieties that culti-
vators in Panama had historically grown as food and shade crops.
76
In
addition to bananas, some native plants, including Heliconia, may have
served as a host forF. oxysporum in forest environments.
77
However, prior
to the rise of the export banana trade, epidemics were rare because ''plan-
tations were small and scattered.''
78
The landscape mosaics of small farms
and banana-free blocks of land inhibited the movement of the soil-borne
pathogen, and consequently, infected populations remained isolated.
79
Also,forcultivatorswhoplantedbananasprimarilyasashadecropand/or
for home consumption, a couple of wilting plants would not generate
much concern because the farmers' livelihoods were not tied to maximiz-
ing production of a single banana variety. But when thousands of people
cleared forests and planted Gros Michel banana plants forexport, the sig-
nificance of plant and pathogen changed in reciprocal fashion.
The expansion of export banana farms transformed ecosystems char-
acterized by a high diversity of plants and low population densities of
individual species into an agroecosystem comprised of monocultures of
extremely limited diversity.Within individual banana farms, dense plant-
ings of Gros Michel clones favored the plant-to-plant dispersal of Panama
disease.
80
On a regional level, the removal of vast tracts of lowland forests;
the installation of drainage and irrigation canals; and the building of rail-
roads that carried field workers, tools, animals, and planting materials all
but guaranteed the pathogen's spread between farms. Finally, increased
steamer tra
c between Caribbean banana ports facilitated the pathogen's
movement across geopolitical boundaries. In sum, if Panama disease can
be thought of as an invader, it was a secondary one that followed in the
wide ecological swath cut by expanding Gros Michel production.
Growers and government ocials initially responded to the epidemic
byestablishingquarantinesanddestroyingdiseasedplants.
81
InHonduras,
United Fruit's subsidiaries ordered their field workers to apply a disinfec-
