Hot weather is good for pests to grow faster. Coffee trees are increasingly infected with diseases such as those caused by planococcus citri, earthworms, fungus and cicadas.

In the past, it rarely rained in December and January but in the past 10 years, rain in these two months has become common, affecting coffee productivity, according to the Western Highlands Agriculture & Forestry Science Institute (WASI).

Coffee trees in the Central Highlands need watering three times a season, which are 20-30 days apart. Irrigation takes place between January and April but now it normally rains in December and January. Therefore, farmers must use underground water excessively to irrigate their coffee farms in March and April.