No one can deny the enormous contribution coffee has made to Vietnam’s economy, society, and culture over the past decades. Each year, coffee brings in export revenues exceeding 2 billion USD. Hundreds of thousands of households, involving millions of people, depend directly or indirectly on the coffee industry for their livelihoods, jobs, and income.
Yet even as coffee assumes a vital economic role, ensuring that production remains stable and sustainable is a challenging question. In recent years, many conferences—national, provincial, and district level—have focused on this critical issue. For coffee to deliver stable income, reduce poverty, and sustain livelihoods, every stage of the value chain—cultivation, care, harvest, processing, and export—must be carefully managed.
A pressing concern is that coffee pests and diseases have become increasingly complex. Control methods remain limited; many diseases have no specific treatment, and the use of pesticides raises its own problems. For example, the recent widespread outbreak of cicadas damaging coffee roots destroyed tens of thousands of hectares in key coffee-growing provinces such as Đắk Lắk, Lâm Đồng, Gia Lai, and Đắk Nông, causing severe losses and threatening the sector’s long-term sustainability.
Based on field experience, pests and diseases typically appear after harvest, lasting through the end of the dry season and into the early rains—a period when their development is especially fast and intense. Farmers need to recognize the main threats so they can respond effectively. According to the Plant Protection Department, coffee hosts a diverse complex of pests and diseases, including 18 major types. Key insect pests belong to six families across three orders—Coleoptera, Homoptera, and Lepidoptera. The most common problems include mealybugs, root-feeding cicadas, stem, branch and berry borers, coffee leaf rust, and various fungal diseases.
Mealybugs
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Mealybugs are among the primary pests of coffee. Over recent years they have caused large-scale damage across almost all coffee-growing areas. They not only reduce yields but also degrade bean quality. Mealybugs attack from the nursery stage through full production, infesting stems, leaves, shoots, flowers, and young fruit. By sucking sap from flowers and young berries, they reduce fruit set. Infestations peak in the dry season from January to April, then decline when the rains arrive.
Cicadas (Root Feeders)
Cicadas are sap-sucking insects with incomplete metamorphosis (egg, nymph, adult). Eggs are laid on primary and secondary branches. After hatching, nymphs drop to the soil, burrow down, and feed by piercing coffee roots to suck sap. They typically live 10–40 cm below the surface, often within 20–70 cm of the canopy drip line—the zone of greatest root concentration. Heavy infestations severely reduce fine roots, weakening the tree’s ability to take up nutrients and water.
Stem and Branch Borers
These borers drill small entry holes into stems and branches, tunneling inside and creating hollow cavities that block nutrient transport and can kill entire branches or trees. They thrive in the dry season, beginning damage around September–October and peaking in December–January.
Coffee Leaf Rust
Rust appears as tiny pale-yellow oil-like spots on the undersides of leaves. Soon these spots develop a layer of orange-yellow powder—the rust fungus spores. Later, lesions turn whitish at the center, then dark brown, eventually merging and causing large areas of leaf blight. Severe infection can lead to massive leaf drop, branch dieback, yield loss, and even plant death. In the Central Highlands, rust usually emerges at the start of the rainy season.
Fungal Infections
Early symptoms on fruit or branches are tiny white powdery spots, later turning pink. These fungi often attack the undersides of branches and berry stalks, causing twigs to die back and fruit to shrivel and drop. On mature robusta plantations the disease may kill individual branches or, in severe cases, entire trees. Fungi thrive in high humidity and strong light, so infections usually appear in the mid- to upper canopy. They spread rapidly within a tree but move more slowly between trees. In the Central Highlands, outbreaks typically begin in June–July and intensify through September, especially in years of heavy rainfall and high humidity.
Nematodes
Nematodes damage coffee at all growth stages, including in nurseries. In the field, the first visible sign is a patch of poorly growing trees surrounded by healthy ones. Above ground, affected trees show stunted growth, nutrient deficiency symptoms, yellowing leaves, and wilting in hot or dry weather—leading to reduced yield and quality. Below ground, nematodes cause taproot and feeder-root rot. They are common in replanted fields or in high-yielding plantations where organic matter is low and fertilizer use is unbalanced, which weakens the plants’ resistance.
Recognizing these major pests and diseases enables farmers to select appropriate plant-protection methods and targeted treatments, helping their coffee plantations maintain high yields and remain stable and sustainable over the long term.