The Gash Delta is the setting of a cautionary episode in pesticide-intensive agriculture. There, DDT spraying in irrigated cotton fields appeared at first to promise control, but intensified treatment was followed by more bollworms, greater crop damage, and lower yields in twice-sprayed fields. The contrast between sprayed and unsprayed cotton made the cost of the intervention plain: growers would have harvested more by forgoing the spraying.

Agricultural Setting

Some 60,000 acres of cotton were grown under irrigation in the Gash Delta. Early trials of DDT seemed to produce good results, encouraging growers to intensify spraying. The account presents this escalation as the turning point: once treatment spread, trouble began, and the apparent success of the initial trials gave way to a worsening infestation.

The Reversal in the Fields

The bollworm was one of cotton’s most destructive enemies, yet more bollworms appeared as more cotton was sprayed. The comparison between treated and untreated fields reversed the expectation that chemical application would protect the crop: unsprayed cotton suffered less damage to its fruit and, later, its mature bolls than sprayed cotton did.

The harm was measurable in the twice-sprayed fields, where seed-cotton yields dropped significantly. Spraying eliminated some leaf-feeding insects, but that limited benefit was more than offset by bollworm damage. The growers were left with the unwelcome conclusion that their crop yield would have been greater had they spared themselves the work and expense of treatment.

Significance

The episode shows how a control measure can aggravate the agricultural problem it is meant to solve. In the Gash Delta, the pattern was not simply that DDT failed to eliminate a pest: bollworms increased with the expansion of spraying, while damage and lost yield turned the intervention into an economic liability. The fields thus offer a concrete contrast between the promise of chemical control and its observed consequences.