In Peru, potato farmers rely on fungicides to control late blight, the most important disease, and insecticides to control a variety of pests. The study aims to estimate the environmental and human health risk associated with pesticide use through the use of the environmental impact quotient (EIQ) to represent the total hazard posed by all pesticides applied over different potato cultivars.

About half of the fungicide (total formulation) was applied per hectare in Huamachuco (0.8 kg/ha), compared to the other two locations: 2.0 kg/ha in Chaglla and 2.4 kg/ha in La Encañada. Insecticide use in Chaglla was only 0.38 kg/ha while in Huamachuco it was about 0.59 kg/ha and in La Encañada over 2.28 kg/ha. Environmental impact values per hectare were about three to four times higher in La Encañada than in either of the other two locations primarily due to heavy use of highly hazardous insecticides. Lack of correlation of environmental impact with productivity indicated opportunities for improvement.

The high degree of variability in products used among locations as well as the different toxicological properties of the products used makes a purely amount-based comparison of pesticide use less illuminating. The EIQ was helpful in providing information on the potential environmental effect of current application practices. Modifying pesticide application patterns through adequate training on more efficient pesticide use and on integrated pest management strategies would be an effective way to reduce farmer health and environmental impacts in Peru.