Coffee grown in the highlands and perhaps elsewhere are subject to attacks by insects as well as molds and fungus. The current threat is a fungus, I believe. Since the 1980’s the ‘cafeteros’ (coffee farmers) here have mostly used harsh and costly chemicals to combat the threats, including Round Up. During our Peace Corps period we worked with the organic farmers who had once used these chemicals but found them to be too harsh and not always effective.
Coffee grown in the sun needs heavy chemical fertilization as coffee naturally prefers the shade. So the organic farmers first had to provide shade for their plants. Plantanos (plantains) grow quickly and in addition provide additional income, so provided one route to a shaded plantation. They planted other trees as well, many of which provide nitrogen and other nutrients. As the leaves and trunks of the platanos fell they decomposed quickly in the moist soil, providing nutrition for the coffee plants and reducing the need for weeding.
Nonetheless these plants are vulnerable so some of the farmers developed organic solutions. We worked with Lito and Julio Lezcano who have developed solutions which are sprayed on the plants. The fungus which came last year was quite devastating and everyone lost many plants, but they came up with a solution that seems to be working. They have a bed of compost materials which have been seeded with small worms. The compost is used to start coffee plants. It produces a liquid run off when combined with molasses seems to control the fungus.
By comparison, another friend of ours has sun grown coffee. The chemical sprays have proven to be too expensive and not very effective and he is very discouraged.
This is by no means scientific proof of course, but suggests that an organic approach can prove to be more effective in the long run. It is also more friendly to the birds and other creatures and plants that populate this area, famous for its birding and the Biological Corridor, by means of which many birds and other animals migrate from South to North America.