Agriculture and Environment: Bananas

Environmental Impacts of Production: Pesticide Use

Bananas produced for international trade are the most pesticide-intensive of the major tropical food crops.

Grading occurs at the point of packing for export, and only completely blemish-free bunches are exported. The presence of even one blemish on a bunch causes major loss in value or outright rejection.

In pursuit of a 'blemish-free' output
The result is a pattern of "precautionary" pesticide applications at every stage of the production process, whether they are needed or not. The idea is to prevent possible pest outbreaks rather than to treat them when and if they arise, even though spraying these chemicals when the target pests are not present kills more beneficial predators than pests.

Pesticides are viewed as the best way to maximise harvests as well as to lower the risk of loss in the value of the harvest. Export banana production and large-scale domestic banana production in countries such as Brazil depend on chemical controls.

286 pesticides varieties to choose from
Some 286 different pesticides (fungicides, herbicides, and nematicides) have been authorised for use on bananas in Costa Rica either on-farm or in the packing sheds prior to shipping. Most of the chemicals are produced in the United States, Switzerland, or Germany.

20-35% of total production costs
The use and cost of these chemical inputs is increasing. Pesticide use in banana production can reach 40 kilograms per hectare per year. In 1991 Costa Rica imported U.S.$56 million of pesticides, in 1994 $84 million, and in 1996 $100 million. In general, pesticides represent 20 - 35% of the total costs of banana production. The cost of fighting the disease black sigatoka alone can be as high as U.S.$1,000 to $1,200 per hectare per year.

"Toxic cocktail" impacts
In Belize, banana companies tend to mix all agrochemicals together and then spray them from a plane on a regular basis (usually about once a week, but sometimes more often). This spray is referred to by locals as "toxic cocktail." It affects not only the bananas, but also the workers in the fields and their families who live in and alongside the fields, the biodiversity next to the plantation, and the water systems that flush the banana plantations on a regular basis. This latter point is very important.

Constant water requirement
Bananas are planted on ridges with deep trenches cut between the rows of plants. The roots cannot survive in standing water, but the plants need water continuously. This means that water is a constant in banana plantations, and it is always flowing in or out to achieve the right balance.

The use of chemicals in the banana export industry is particularly important because, in most parts of the world, banana plantations have been established on the fertile, flat lands of coastal areas. This means that all the chemicals will more often than not have a relatively immediate impact on coastal wetlands as well as the inshore coastal areas and even nearby coral reefs.

For example, it is well documented that 60 - 85% of all fertiliser is lost via leaching and/or runoff (Usher and Pulver 1994). Nitrogen, potassium, and calcium are lost rapidly via leaching. In contrast, most phosphorous is attached to soil particles and is only leached if the soil sediment is washed off the plantations.