Agriculture Reference
In-Depth Information
than average fruit bunches and are very susceptible to uprooting dur-
ing windstorms. 78 In 1950, United Fruit experimented with controlling
root borers through an intensive trapping method designed to kill adult
weevils. 79 Three years later, a study concluded that trapping was ''effec-
tive in reducing the populations [of root borers],'' but was not as ''e -
cient'' as the insecticide Dieldrin which reportedly could control root
borer populations for up to two years after application. 80 In 1954, the
company began applying Dieldrin spray at a recommended rate of once
per year except where root borer populations were ''extremely high.'' 81
United Fruit laterapplied Dieldrin in the forms of granules and dusts that
provided longer-lasting control than spray formulations. As late as 1960,
United Fruit's Norwood Thorton declared that ''chemicals continue to be
the main weapon for root borer control,'' and cited an example in which
a single application of Dieldrin had brought a major infestation of borers
under control within two months. 82
However, not everyone on United Fruit's research staff was enthusi-
astic about the use of Dieldrin. In the mid-1950s the department's news-
letter urged farm managers to control borer populations through cultural
practices such as planting insect-free rhizomes. A subsequent newsletter
stressed the need to practice farm sanitation in order to make condi-
tions ''unfavorable'' for pest populations. The letter concluded by exhort-
ing farm managers to ''reduce your insect populations without the use of
sprays!'' 83 In 1956, a Cornell University toxicologist studied residue levels
of Dieldrin in soils and concluded that ''frequent applications'' could re-
sult in a potentially dangerous build-up of the insecticide. 84 That same
year, United Fruit entomologist Furber S. Roberts gave a paperat the 10th
International Congress of Entomology that provided several examples in
which Dieldrin applications eliminated ''beneficial insects'' such as ants
and lady bugs, provoking subsequent surges in populations of herbivor-
ous insects with no previous history as ''pests.'' By disrupting patterns of
predation and parasitism among insects, Dieldrin and other persistent in-
secticides helped give rise to new ''enemies'' of the banana plant. Roberts
concluded by stating that biological and cultural methods appeared to be
the most satisfactory means to control root-borer populations. 85 Oneyear
later, after observing that an application of Dieldrin had destroyed ant
populations that played ''an important role'' in controlling other insects,
United Fruit's research department warned farm personnel that ''indis-
criminate use of insecticides may not be economically sound and could
lead to problems greater than those for which control was attempted.'' 86
A broad-spectrum killing power was only one of Dieldrin's draw-
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