The average annual rainfall in the UCRB varies from 1200 mm to 3000 mm,
with an average of 2215 mm. Almost 70% of this rainfall occurs in the
wet season. The wet season typically starts in November and ends in
April, with an average monthly rainfall of approximately 250 mm (typical
range: 100-500 mm). During the dry season from June to September,
monthly rainfall is usually less than 50 mm (Deltares, 2010). Other
months constitute a transitional period. The high annual rainfall and
the mean daily temperature that varies between 18˚C and 30˚C provide
favorable climatic conditions for growing vegetables in the UCRB.
2.2 Survey Design and Data
Collection
A questionnaire was designed to obtain information about the amount and
types of pesticides used by farmers living in the UCRB agricultural
area. The questionnaire comprised 21 questions (see Supplementary Data 1 ) that focused on: 1) general information
about the respondents (name, gender, age, address); 2) farmland
information such as area, type of crops, harvest, planting period, and
planting frequency per year; 3) pesticide application data such as
brands purchased, type of pesticide, quantity, and frequency of
application.