The costs of pesticide use

The primary reason behind the increase in insecticide use has been the relatively low cost of these products. Advances in the chemical industry have produced highly affordable pesticides. Many observers mistakenly view pesticides as expensive inputs that destroy farmers’ profit margins. The fact is that pesticide costs, even in intensive production, absorb only a small share of the total value of the rice crop (Table 1). Farmer surveys conducted for five years in eight rice bowls in China, India, Indonesia, Thailand, Vietnam and the Philippines found that total pesticide costs accounted for less than 73% of the gross value of production, on average across the sites. In the Philippines, the share was just 52%.

Table 1. Pesticide use per crop in some rice bowls of Asia, (1994-99) (arranged in order of increasing pesticide use).

In addition to direct monetary costs, there are however, many hidden costs associated with the indiscriminate use of pesticides. Pesticides kill the natural predators of many insect pests, such as spiders, thus contributing to pest outbreaks instead of preventing them. One of the worst examples of this phenomenon occurred on the Indonesian island of Java in the 1980s, when excessive pesticide use decimated the insect populations that preyed on the brown planthopper. The planthopper’s short breeding cycle then allowed it to breed unchecked by predators.

Worse, excessive pesticide use has damaged the health of farmers and consumers. Because of poor training and/or lack of money for buying proper pesticide application equipment, farmers are directly exposed to chemicals that injure their eyes, skin, respiratory tract and nervous system. Studies by Agnes Rola of the University of the Philippines Los Baños (UPLB) and Prabhu Pingali, formerly of IRRI, showed that the costs to farmers’ health outweighed the benefits gained from pesticides. Furthermore, farmers sometimes apply pesticides very close to harvest, which may endanger the health of consumers.