Pesticide usage by farmers in Pagsanjan-Lumban catchment of Laguna de Bay, Philippines

Pesticides have been of great benefit to agriculture in the Philippines by decreasing crop losses due to insects, weeds, plant diseases, rodents, and other pests. However, they may build-up in the food chain and can cause contamination of the environment. We examined farmers’ pesticide usage in southern sub-catchments of Laguna de Bay, which is a crucial water resource subject to intensive investigations to identify types and sources of pollution. Before the monitoring of pesticides in surface waters was commenced it was necessary to conduct a survey of the pesticides being used by the growers in the catchment in order to select the pesticides that should be monitored.