The number of pesticide applications per year is based on the monthly
average number of applications (Supplementary Data 3 ). In case
the farmer used more than one pesticide brand containing the same
pesticide, this was counted as one application event. Figure 3 shows that the number of applications per year is highest on vegetables,
most notably Abamectin, Mancozeb, and Profenofos in long bean,
Difenoconazole and Mancozeb in cabbage, and Maneb in chili. In
vegetables such as chili, tomato, and broccoli, Profenofos and Mancozeb
were applied 5-7 times/month on average. Application frequency was even
higher in cabbage with an average frequency of 8 - 10 times per month.
These two pesticides are typically used to control caterpillars,
whiteflies, and mealy bugs (Profenofos), and leaf diseases such as leaf
spot and rust (Mancozeb) (Derbalah et al., 2019). For rice, as the most
surveyed crop, the application frequency is mostly less than once per
month, or 1-3 times per growing season (3 - 4 months). Overall,
Abamecetin, Mancozeb, Maneb, and Profenofos are pesticides that are
applied at the highest frequency for most crops.