Coffee Major Pest and Diseases and Control Measures

Plant protection 

Coffee is a crop that is susceptible to a variety of pests and diseases. Some common pests that affect coffee plants include coffee berry borer, coffee leaf miner, and mealybugs. Common diseases that affect coffee plants include coffee leaf rust, American leaf spot, and coffee berry disease.

Keeping your plantation safe is a year-round task that requires constant monitoring and management to prevent the spread of pests and diseases from maintaining healthy growth and optimizing crop yields.

Coffee Plants Major Pests and their Control Measures 

The presence of pests in large numbers, whether insects, animals, or other organisms of the same species, can cause severe harm to your coffee plantation. This sudden and widespread invasion can result in complete crop destruction and disrupt the normal progress of agriculture. Coffee plantations are also susceptible to this menace.

Some of the most common pests in coffee are:

1. Coffee Berry Borer (Hypothenemus hampei)

Without a doubt, one of the most harmful pests faced by coffee farmers is the coffee borer. These insects are native to Central Africa and are black and shiny with a cylindrical body, globular head, and a body length of 1 to 1.25mm for males and 1.40 to 1.80 mm for females. The female can lay 2 to 3 eggs per day for 20 days. The insects burrow into the top of the coffee berry, creating galleries inside the seed where they lay their eggs. If the eggs are laid early in the berry’s development, the berry falls off; however, the biggest problem occurs when the eggs are laid during the mid-development of the grain, as this creates ideal conditions for the insects to feed, live, and lay more eggs. The female remains inside caring for her offspring until death, and new females emerge already fertilized, ready to invade more berries. This results in lighter coffee beans and a quality decline.

Control:

• Make sure that all the berries from your previous harvest have been removed. Dried and immature berries are always left on trees, and it is also common to drop them on the floor by mistake. This means that rounds should be made to collect, bury, or burn these unused coffee beans. If you leave them, you will attract more berry bores to come.
• Constantly balance the shade of your plantation. Eliminating excess branches from shade trees will allow light and enough ventilation into your plantation.
• Use biological control. In an agroforestry system, birds on your plantation can act as natural predators for the coffee berry borer insects. Another biological solution is using Cephalonomia stephanoderis, a parasitoid wasp species that lays its eggs on the borer larvae, which helps to control the population of the pest. Another option is using sprays of Beauveria bassiana, an entomopathogenic fungus that naturally infects and kills the coffee berry borer. Farms that use C. stephanoderis and B. bassiana tend to set up labs for this control.
• Bottle trapping is a viable and inexpensive method for controlling coffee berry borers. It involves cutting the bottom off a red plastic bottle, burying it or hanging it near a coffee plant with the opening facing up, and filling it with a mixture of water and a small amount of alcohol or detergent. The red color and the scent of the mixture attract the borer insects, which fall into the bottle and are unable to escape, ultimately drowning. This method is effective because the borers respond to visual, physical, and chemical stimuli. It is most effective when combined with other control methods, such as cultural practices and biological control.
• Chemical products are only recommended as a last resource once the pest has gone out of control and is economically affecting your plantation.

2. Root Mealybug (different species)

These insects live attached to the coffee roots and are often difficult to detect because they are underground. Mealybugs may form a symbiotic relationship with certain ant species, which can indicate their presence. The mealybugs feed on the sap from the coffee roots but cannot digest it, excreting a sugary substance called “honeydew”. Ants benefit from the sugar in this waste. Species of root mealybugs that affect coffee include Puto barberi, Neochavesia spp., Rhizoecus spp., Pseudococcus jackbeardsley, Dysmicoccus spp., and Geococcus coffeae. A similar type of mealybug, the Planococcus Citri Risso, can be found in the leaves and between the coffee berries.

Control:

• It is believed that coffee trees become infested with root mealybugs from the seedling stage. To avoid transferring the pest to a plantation, it is advisable to implement proper control measures in coffee nurseries. Also, if you detect that a seedling you are about to transfer to your plantation has this, you should discard it instead of planting it.
• Chemical control is the most effective way to combat mealybugs. Products containing Dimethoate, Diazinon, and dimethoate are commonly used, but remember that they have different toxicity levels, so you should read their labels properly before using them.

3. Coffee Leaf Miner (Leucoptera coffeella Guer)

The Leucoptera coffeella Guer is a small insect that is a significant pest of coffee plants. It is a tiny, light-colored moth with large antennas. It is native to South America and is found in coffee-growing regions worldwide. The female moth lays its eggs on the undersides of coffee leaves. After about a week, the larvae hatch and burrow into the leaves to feed for about 3 weeks. This feeding causes damage to the leaf tissue, resulting in visible brown spots or “mines” that can reduce the foliage and photosynthetic ability of the coffee tree if found in large numbers. The population of coffee leaf miners reaches its peak during the summer but decreases significantly during the rainy season.

Control:

• Using agroforestry practices that will maintain the temperature in your plantation. High temperatures might allow it to proliferate.
• Chemical control is again the most effective solution, but it should only be used when they are found in high numbers.

Other coffee pests include white grubs (Phyllophaga sp.), scale insects (Coccidae), red spider mites (Olygonychus punicas), and crickets. The list is extensive, and the level of threat varies in each region depending on the coffee’s growing conditions and altitude. Always consider biological control before using chemical solutions.

Disease control

Plant protection will only be complete if the proper care and attention are given to common coffee diseases. The best way to achieve this is by constantly observing your plantation and having rigorous control over your cultural practices to firstly be able to prevent any diseases from coming into your farm and secondly to be able to act upon any threats that are found timely.

Common diseases of Coffee trees 

Some of the most common diseases in coffee are:

1. Coffee leaf rust

Scientifically known as Hemileia vastatrix Berk & Broome, this fungal disease affects coffee plants and causes yellow-orange spots on the leaves, which lead to defoliation and decreased coffee production. In addition, it does not allow the coffee berries to ripen at the same pace, which makes it take longer to collect the crop. The yellow spots under the leaves are dusty spores that disseminate quickly, especially in warm climates. It is spread by windborne spores of the fungus climate change, and increased global trade has led to its spread worldwide. I have mentioned it in previous articles, as the impact has been huge in recent years, and no coffee plantation worldwide is exempt from its threat.

Control:

• Even though no coffee plant is immune to this disease, some varieties have shown certain levels of resistance and recover faster from leaf rust. It is recommended to plant them to keep the rust under control.
• The use of fungicides is the main form to combat this fungus. So far, the ones that contain copper (dicopper chloride trihydroxide, cuprous oxide, copper hydroxide, and copper sulfate) have shown effectiveness in preventing the disease, as they act by contact inhibiting spores’ germination and prevent them from entering the plant. Fungicides with triazoles (cyproconazole, triadimefon, hexaconazole, and propiconazole), on the other hand, work systemically by being absorbed by the plant and work not only as a preventive measure but also as therapy for the bushes once they are sick.

2. American Leaf spot of coffee (Mycena tricolor)

This is found in coffee plantations above 700 m altitude, where there is an excess of shadow and a high humidity level with fresh temperatures. It provokes damage to the plant’s branches, fruits, and leaves. Its dissemination is slow. Dark brown circular injuries that later turn light brown are a clear sign of this disease. The plant eventually loses an excessive amount of foliage, reducing its ability to photosynthesize.

Control:

• Maintain a balanced level of shadow according to the needs and location of your plantation.
• Biological control can be achieved by using Trichoderma spp., which inhibits the formation of the Mycena fungus. However, it is essential to note that while this reduces the multiplication capability of the pathogen, it is not sufficient to eliminate it completely.
• Products containing Tebuconazole + Triadimenol, Cyproconazole, Azoxystrobin, and copper oxychloride can be used to combat this disease.

3. Coffee berry disease, CBD (Colletotrichum sp.)

This species of the fungal disease affects mainly Arabica species, and even though Robusta has shown high resistance levels, it is not entirely immune to this disease. Different variants appear throughout the countries where coffee is cultivated. This fungus might appear in the stems, the leaves, and the coffee varieties when they are not ripe (green berries). In advanced stages, the coffee Berries dry out and acquire a dark color. It is believed that plantations with low levels of fertilization and low soil moisture are more susceptible to this disease.

Control:

• Ensure that your coffee plantation has a balanced supply of nutrients. Avoid excessive light exposure. Add sufficient organic matter to the soil (especially in sandy soils) to prevent conditions that may lead to the proliferation of CBD in the plants.
• Fungicides that contain copper and triazoles are effective in combating this disease. Note that plants sick with Coffee Leaf Rust are susceptible to CBD.

4. Cercospora Leaf Spot (Cercospora coffeicola)

This fungal disease occurs in coffee plantations that lack proper nutrient balance. It spreads through wind and rain splash and thrives in humid and warm environments. The symptoms can be observed in newly generated leaves and tissue, appearing as brown spots that start at the edges of the coffee leaves and spread toward the center. The disease can also be seen on the branches, starting at the spots where leaves have fallen.

Control:

• Keep a balance and controlled fertilization plan, add organic matter to your soil, and balance the shadow& lighting of your plantation.
• Fungicides that contain copper and triazoles are effective in combating this disease.

Other common diseases found in coffee plantations include Phoma, Corticium salmonicolor, Pellicularia Koleroga, Rosellina sp., and Ceratocystis fimbriata, among others. Their occurrence ratios may vary in different coffee-producing countries, but most of these diseases are caused by fungi and bacteria. Proper control of these diseases will ensure both the quantity and quality of your crop.

It is crucial to have a well-planned calendar for your coffee plantation to manage potential threats to your crop effectively. This includes utilizing a combination of cultural, biological, manual, and chemical methods. It is crucial to understand that this management should be ongoing and consistent. Scheduling regular monitoring and interventions will help prevent and mitigate the impact of diseases and pests on your coffee plants.

References:

CENICAFE Centro Nacional de Investigaciones de Café, Colombia https://biblioteca.cenicafe.org/bitstream/10778/717/9/9%20Manejo%20y%20control%20integrado%20malezas.pdf

University of Hawaii at Manoa https://www.ctahr.hawaii.edu/site/cbbmanage.aspx

Federación Nacional de Cafeteros de Colombia, Avances técnicos CENICAFÉ, Vol. 386, 2009 https://biblioteca.cenicafe.org/bitstream/10778/391/1/avt0386.pdf

Factsheets for Farmers, Tanzania, Oct. 2012 https://www.plantwise.org/FullTextPDF/2013/20137803401.pdf

ANACAFÉ Guatemala, Boletín Técnico, Feb. 2020 https://www.anacafe.org/uploads/file/23aa9467eb854dc2848f673a89b40311/Boletin-Tecnico-CEDICAFE-Febrero-2020-02.pdf

La Roya del Café en Colombia, CENICAFÉ, No. 36, 2014https://www.cenicafe.org/es/publications/bot036.pdf

SAGARPA, México, Ficha técnica 49 http://royacafe.lanref.org.mx/Documentos/FTNo49Mycenacitricolor.pdf

• Guía Técnica de Caficultura 2018, Anacafé Guatemala p. 156-211

Coffee plant History and general Information

Coffee Plant Information – Morphology

Coffee Genetics and Variety Selection

How to Select, and Treat Coffee Seeds

Germination of Coffee Seeds and Creation of Seedbeds for Planting

Coffee Trees Planting and Plant Spacing

How to Prune your Coffee Trees in an Agroforestry System

Shade-Grown Coffee in an Agroforestry System

Coffee Tree Flowering and Pollination

From Rainwater Harvesting to Irrigation of Coffee Trees

Coffee Tree Fertilization Requirements

Weed Management in a Coffee Plantation

Coffee Major Pest and Diseases and Control Measures

Coffee tree Harvesting – Coffee Berries Picking