Agriculture Reference
In-Depth Information
cluding the use of shade crops and/or disease-resistant varieties. In 1937,
Gerold Stahel, a researcher at the Surinam Agricultural Experiment Sta-
tion, observed that when he placed banana plants inoculated with Siga-
toka spores under a glass roof they did not show symptoms even when
plantsjustoutsidetheroofwerecoveredwithspots.
57
Stahelsurmisedthat
the fungus would grow only if the plant tissue was covered with a film of
water (i.e., dew), a hypothesis confirmed by later researchers.
58
His find-
ing suggested that Sigatoka could possibly be controlled through the use
of shade crops.
Three years later, Jamaica-based plant pathologist R. Leach argued
that shading could prevent excessive heating of plant foliage and retard
the rate of cooling, thereby reducing dew formation. ''There is no doubt,''
headded,''thatshadeproduces...anaturalcontrolofleafspotinmany
districts in Jamaica.''
59
Leach considered shading to be a viable Sigatoka
control under certain environmental conditions: ''Although there may be
a prejudice against the use of shade for bananas, it is not improbable that
the use of a properly controlled, light shade may ultimately prove the
most economic means of control, without the use of sprays, in those areas
where dew formation is not excessive during most of the year.''
60
Around
the same time that Leach published his findings, plant pathologist C. A.
Thorold reported that when Sigatoka hit Trinidad, Gros Michel plants
grown in monocultures were affected much more than those planted with
cacao and/or Erythrina trees.
61
The Trinidad Agricultural Department
subsequently set up experiments to determine if intercropping Gros
Michel plants with cacao orErythrina could reduce the incidence of Siga-
toka. Thorold stated that the results ''left no doubt that shade effectively
checks the Leaf Spot disease so that a normal healthy bunch can be ma-
tured.''
62
He did not deny the e
cacy of Bordeaux spraying, but he
doubted whether it would be viable in Trinidad where banana farms were
''small and scattered.''
Thorold warned that the frequency of scratches and blemishes on
banana peels would increase as a result of intercropping because both
cacao and Erythrina trees provided habitats for tree-dwelling mammals
andthrips(Frankiniellaspp.)thatcouldblemishbananapeels.Thiscaveat
alluded to the market structures that continued both to shape scientific
research and to impede small-scale growers from competing with the
high-input, large-scale production processes of the U.S. fruit companies.
Shading might have been capable of controlling Sigatoka on small farms
at a fraction of the cost of Bordeaux spraying, but scarred fruit would
have fared poorly on U.S. mass markets where a premium was placed
