Common coffee pests and diseases and their control

Coffee production is growing rapidly in Uganda as more people take up coffee growing, its market is assured and prices are quite attractive.
For a long time in the past, the country’s average annual coffee production stood at three million 60kg bags, but last year Uganda produced seven million 60kg bags according to the Uganda Coffee Development Authority (UCDA).
However, we are struggling to increase production against the prospects and challenges of climate change, whose footprints are right before our eyes.

Pests and diseases
Among the great challenges of the coffee grower today are pests and diseases, many of which are new in the history of the coffee crop.
Robert Ssentamu, UCDA regional coffee extension officer for Sembabule and Bukomansimbi districts believes that the best way to tackle the challenges is for farmers to adopt good agricultural practices, soil nutrient management and pest and disease management and control.
“Here in the central region we grow Robusta coffee, which has its own diseases, and in eastern Uganda and parts of western Uganda, they grow Arabica coffee, which also has pest and disease problems,” he says. “Some of the problems, such as extreme weather conditions and lack of soil nutrition, are of course present in all regions.”

Coffee wilt disease
Coffee wilt disease, which wiped out 56 percent of the crop in 2005, is said to be one of the most devastating diseases of Robusta coffee. “It was first noticed in Bundibugyo in 1993, but it’s amazing how quickly it spread to the rest of the country,” he told Seeds of Gold. “In 2006, Uganda barely produced even two million bags,” he added.
According to him, CWD is a fungal disease that kills coffee trees by blocking the flow of water and nutrients from the branches. “The branches wither one after the other until the whole tree dries up,” he says.

How to control wilting
The dead tree remains infectious for years and must be uprooted and burned where it has been. Ssentamu warns that the virus survives on the ground and can be spread by running water, wind and sharp tools. “Infection occurs when the virus comes into contact with a bruised part of another tree,” he says. He also recommends the application of fertilizers, because the strong power of the plant increases its tolerance to the disease.
He advises farmers to practice high hygiene, disinfecting their tools each time they use them to work on a diseased tree before going to work on another.

“Unfortunately, infected trees do not always show symptoms of infection and some healthy-looking trees may already be infected. So the best practice would be to disinfect the tools after each tree is worked,” he says.
Disinfection involves immersing the instrument in a container of a disinfectant such as JIK or passing the instrument over a flame. He also advises farmers to fill in adequate gaps to avoid situations where branches of diseased trees cross with healthy ones.
“All new farmers getting into robusta coffee growing and others struggling to stock their gardens should switch to the CWD resistant varieties available at all UCDA registered coffee farms,” says Ssentamu.

“In fact, the advent of CWD-resistant lines has removed the threat of the disease from coffee farmers.” He says coffee varieties are also selected and bred to resist or withstand many coffee pests and diseases, in addition to being high yielding and producing large coffee beans.
Black Coffee Bean (BCTB)
Ssentamu reveals that perhaps the worst Robusta coffee pest today is the Black Coffee Twig (BCTB).
According to some studies, this pest has caused nine percent of the total annual loss and is present in 69 percent of the farms in the 26 districts surveyed, attacking 40 percent of the plants in each of them.

According to Ssentamu, BCTB was also first noticed in Bundibugyo district in 1992. The plague, which is visible to the naked eye, spreads very quickly, especially during dry periods. He says he can cover a distance of up to 200 meters in a few minutes. She lays her eggs in the branch of the coffee tree after making a hole. Between 25 and 30 days the eggs hatch but the chick dies in the process. High tree shade conditions are the best environment for BCTB and Ssentamu advises farmers to cut back all shade trees in gardens and ensure trees are planted at appropriate spacing, such as 60 feet apart.

He says some trees are particularly good hosts for pests and should not be planted in or around coffee plantations. These trees are lusambia, musizi and avocado.
“Shade trees planted on the coffee plantation should be well pruned to discourage the possible host of BCTB because it disturbs the high altitudes. The pest attacks more than 200 different plants in the world and here in Uganda it attacks about 45 plants,” he says. “It is a dangerous pest and can also attack CWD-r lines,” he added.
Encourages farmers to work more closely with agricultural extension officers on control measures that include the use of pesticides sold in farmers’ markets. Some helpful pesticides he mentioned are kohinor, confidor, imax, immidacloprid and tebuconazole.

Another way to combat BCTB is to use alcohol traps placed here and there within the plantation. Ssentamu has also warned farmers to be careful when buying coffee plants.
Pests often also attack coffee farms, which is why farmers should only go to UCDA registered nurseries for planting material.

Deus Nuwagaba, the deputy executive director of the National Union of Coffee Farming and Agricultural Enterprises (NUCAFE), attributes most of the coffee pests and diseases to poor management practices and failure of farmers to test the soil before planting the crop. “Most pests and diseases of the coffee crop are soil-born and there is a general nutrient imbalance and water stress where CWD exists. So it’s important for farmers to thoroughly test and analyze the soil in their plantations to find out what nutrients are lacking and what pests are present in the soil,” he says. .

Coffee berry punch
Nuwagaba cites the coffee berry borer as a serious problem, especially in Arabica coffee, as they cause extensive damage, possibly with a yield loss of 50 percent. It bores holes in the coffee cherries, causing them to fall off the tree when they are still green, and the others that don’t fall get defective beans. Dead or damaged cherries should be destroyed, as they are a source of further infection.
Nuwagaba says the stem borer is a big problem especially in Arabica coffee fields. It is a beetle that bores holes in the stem of the coffee tree and kills it. It can kill a stand of trees and reduce farm yields.

The larvae remain inside the tree and continue to develop if the branches are not destroyed in time. The use of chemicals such as fenitrothion is recommended, but it is important to follow the manufacturer’s instructions closely.
There are many other pests and diseases of the coffee crop. Farmers should always consult trained farmers for advice and guidance on how to do this.

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