15 Common Mango Tree Diseases and Problems (With Proven Fixes)

A healthy mango tree can feed a family for decades. Left unprotected, though, it can lose its flowers, fruit and even its branches in a single wet season. I have seen growers walk past a tree for weeks without noticing the early signs.

This guide covers the 15 most common mango tree diseases and problems. For each one, you will learn what to look for, why it happens and how to respond. 

Many problems start at the same time of year. In Florida, anthracnose, powdery mildew and cold weather during bloom are the biggest limits on mango production. The same pattern appears in tropical regions worldwide.

Good orchard habits prevent most of these problems. Regular checks, clean ground and timely action matter more than any single spray. Let us begin with the most serious disease.

Fungal Diseases of Mango Trees

1. Anthracnose

Anthracnose is the disease most mango growers fear. It is caused by the fungus Colletotrichum gloeosporioides. University of Florida extension staff note that it attacks flowers, young fruit, leaves and twigs, and it also causes rot in stored fruit.

Look for small, dark, angular spots on leaves. On fruit, you will see black, sunken patches that spread as the mango ripens. Flowers turn black and drop before they set fruit.

The disease thrives in wet weather. Research from the University of Florida shows that the worst losses occur where rain falls throughout flowering and fruiting. Infections can also stay hidden in green fruit until ripening.

For control, prune out dead twigs and remove fallen leaves and fruit. The University of Florida reports that copper fungicide sprays, applied regularly from the start of flowering, reduce infection in developing fruit. Always follow the product label.

2. Powdery Mildew

Powdery mildew is the second major fungal threat. The cause is Oidium mangiferae. The disease is easy to recognize once you know it. A white, powdery coating appears on flower stalks, young leaves and tiny fruit.

Cool, dry nights with warm days favor this fungus. In severe cases, the whole flower panicle can be covered and the fruit fail to set. I find this disease more frustrating than anthracnose because it strikes at the exact moment the tree is flowering.

Check flower panicles weekly as buds open. Remove badly infected panicles and destroy them. Sulfur-based or other registered fungicides work best when applied early, before the white growth spreads.

Good airflow also helps. Prune the canopy so sunlight and wind reach the inner branches. Avoid heavy nitrogen feeding during bloom, because soft new growth is more vulnerable.

3. Mango Malformation Disease

Mango malformation is one of the strangest-looking problems in the orchard. Flower panicles become thick, crowded and bunched, with almost no fruit. Young shoots may also swell into tight, deformed clusters.

The disease is linked to Fusarium mangiferae. A 2006 review by researchers at the University of Florida and the University of Pretoria noted that it occurs across Asia, Africa and the Americas and was first reported in India in 1891. This is not a new problem.

There is no simple cure. Prune infected shoots well below the visible damage and burn or bury them. Use disease-free planting material when you establish new trees.

Do not move cuttings or grafting wood from an infected orchard. Sterilize pruning tools between trees. Some cultivars show stronger tolerance, so ask your local extension office which varieties suit your area.

4. Mango Scab

Mango scab is caused by the fungus Elsinoe mangiferae. It mainly attacks young leaves, shoots and small fruit. The spots look like rough, raised, grey-brown scabs.

University extension sources explain that scab colonizes young leaves, and cool, wet conditions favor it. Fruit that are infected early may become corky and cracked. They are often unsellable, though still edible.

Scab usually does less damage than anthracnose, but it spoils the fruit’s appearance. Growers who sell at market feel this loss most. A clean-looking mango simply sells faster.

The same copper sprays used against anthracnose also help here. Begin treatment when new flushes appear. Remove infected leaves and avoid overhead watering, which spreads spores.

5. Stem-End Rot

Stem-end rot is mainly a problem after harvest. A dark, soft patch begins at the stem end of the fruit. It then spreads inward and turns the flesh brown and watery.

Several fungi can cause it, especially Lasiodiplodia theobromae. University of Florida research notes that stem-end rots can be serious where anthracnose is present but well controlled. In other words, fixing one disease can reveal another.

Prevention begins in the orchard. Cut dead branches, keep the canopy open and harvest with a short stem attached. Handle fruit gently, because bruises give fungi an easy way in.

After picking, keep fruit cool and dry. Many commercial packers use a warm-water dip, but home growers can simply avoid stacking wet fruit. Check stored mangoes every day.

6. Alternaria Black Spot

Alternaria black spot causes dark, slightly sunken spots on the skin of ripening fruit. The patches often look dry and velvety. They can join together and cover much of the fruit.

This disease is more common where it is dry. The same University of Florida review states that Alternaria black spot is important in dry regions where anthracnose is not significant. So growers in drier climates should watch for it.

Damaged or overripe fruit is most at risk. Harvest on time and avoid leaving ripe fruit on the tree too long. Remove fallen fruit from the ground, since it carries spores.

Good sanitation is again the foundation. Store fruit in clean, ventilated crates. Discard any mangoes with spots instead of keeping them with healthy ones.

7. Algal Leaf Spot

Algal leaf spot surprises many gardeners because it is caused by an alga, not a fungus. The organism is Cephaleuros virescens. It forms rusty, orange-to-green velvety patches on leaves and sometimes on twigs.

University of Hawaii and University of Florida resources identify Cephaleuros virescens as the cause of algal spots on mango leaves. The patches look alarming, but the damage is usually mild on healthy trees.

The alga likes humid, shaded and crowded conditions. Dense canopies that stay wet for long periods encourage it. Weak trees suffer most.

Pruning is your best tool. Open up the canopy and improve airflow. Keep the tree well fed and watered. Copper sprays can reduce heavy infections, but most home trees recover with better care.

8. Sooty Mold

Sooty mold looks like black soot has settled on the leaves. You can often rub it off with your finger. The fungus does not attack the leaf directly. Instead, it grows on sticky honeydew left by insects.

The real problem is the insect pest. Mango hoppers, scale insects and mealybugs all produce honeydew. A heavy black coating blocks sunlight and slows photosynthesis.

If you see sooty mold, look for the insects first. Check the underside of leaves and the flower panicles. Treating only the mold gives temporary results because the honeydew keeps coming.

Control the pests with registered insecticides, horticultural oil or soap sprays, as local advice allows. Once the insects are gone, the mold weathers away on its own. Rain helps wash it off.

9. Verticillium Wilt

Verticillium wilt is a soil-borne disease. It enters through the roots and blocks the tree’s water channels. Branches wilt and die back suddenly, often on one side of the tree first.

University extension sources list Verticillium wilt as a mango disease caused by Verticillium albo-atrum. It is less common than anthracnose but can be severe in affected orchards. Young trees are especially at risk.

There is no reliable cure for infected trees. Plant in well-drained soil and avoid planting where wilt has appeared before. Do not overwater, since soggy soil favors the fungus.

Remove and destroy dead trees so the disease does not spread. Disinfect your tools after use. Choose healthy nursery stock from reputable suppliers.

10. Mango Decline and Dieback

Mango decline describes a slow loss of tree vigor. You may see yellowing leaves, dead twigs and cracked bark that oozes gum. In bad cases, whole limbs die.

The causes are often mixed. Fungal infections, poor drainage, drought stress and damaged roots can all play a part. The University of Florida has studied this issue under the title “A Reexamination of Mango Decline in Florida”, which shows how complex it can be.

Start by finding the stress that triggered it. Check soil drainage, watering habits and nutrient levels. A soil test costs little and can reveal a hidden deficiency.

Prune dead wood back to healthy tissue and seal large cuts. Water deeply but not too often. Mulch around the tree, keeping it away from the trunk. Recovery takes a full season or more.

Insect Pests and Other Problems

11. Oriental Fruit Fly

The oriental fruit fly is one of the most destructive fruit pests in the world. Females lay eggs just under the skin of ripening mangoes. The maggots then eat the flesh, and the fruit rots and falls.

University of Florida researchers report that this fly has been recorded on 478 kinds of fruit. That huge host range explains why it spreads so easily. An extension agent at the University of Hawaii adds that one female can lay more than 1,000 eggs in her lifetime.

Look for tiny puncture marks, soft spots and maggots inside the fruit. Cut open a suspect mango to check. Fallen fruit should never stay on the ground.

Pick up and bag fallen fruit every few days. Use traps to monitor the flies. Bagging individual fruit works well in small orchards. In regulated areas, report any suspected finds to your agricultural authority.

12. Mango Seed Weevil

The mango seed weevil lives inside the seed. The outside of the fruit may look perfect. This makes it a hidden threat that spreads easily when people move infested fruit.

An adult is small, about 8 mm long and 4 mm wide. Kenya’s agricultural research body reports that a female can lay around 15 eggs a day, up to 300 over three months. The larvae burrow into the seed and feed there.

Because of this pest, mangoes face tight trade controls. The USDA describes it as a federally quarantined pest that blocks shipments from Hawaii to the continental United States. Detection is difficult, since seeds must be split open to confirm infestation.

For control, clear fallen fruit and seeds, and burn or bury them deeply. Do not move fruit from infested areas to clean ones. Some growers band trunks and use targeted sprays during early fruit development.

13. Mango Hoppers

Mango hoppers are small, wedge-shaped insects that suck sap from flower panicles. Heavy attacks cause flowers to wither and drop. Few fruit remain on the tree.

They also leave sticky honeydew that feeds sooty mold. So one pest often brings two problems. I have watched whole panicles turn black within days because hoppers went unchecked.

Scout during bud break and early flowering. Tap a panicle over a white sheet or tray and count the insects. Early action matters, because the population grows quickly.

Spray only when numbers are high, and use products registered for mango. Avoid spraying during full bloom when bees are active, since pollinators matter. Keep the orchard free of weeds that shelter hoppers.

14. Mealybugs and Scale Insects

Mealybugs look like small white cotton tufts on shoots, leaves and fruit. Scale insects appear as tiny, hard bumps stuck to bark and leaves. Both drink the tree’s sap.

A light infestation does little harm. A heavy one weakens shoots, distorts leaves and spoils fruit. These insects also leave honeydew, which again invites sooty mold.

Ants often protect them from natural enemies. So controlling ants can help control the pests. Sticky bands around the trunk are a simple, low-cost option.

Natural predators such as ladybirds and parasitic wasps help a great deal. Avoid unnecessary broad-spectrum sprays that kill them. Horticultural oil, applied carefully, can control light to moderate infestations.

15. Poor Flowering, Flower Drop and Fruit Drop

Not every problem comes from a pathogen or an insect. Sometimes the tree simply fails to flower well, or drops its fruit early. These are non-infectious problems, and they are very common.

Cold nights during bloom, drought, heavy rain and nutrient imbalance can all reduce fruit set. Too much nitrogen gives lush leaves but few flowers. Mango flowering also depends on weather. After flowering, fruit take 100 to 150 days to reach maturity, so stress during this period shows up later as drop.

Some fruit drop is natural. The tree sheds extra fruit it cannot carry. But heavy, early drop deserves a closer look at water, feeding and pests.

Water young fruit consistently, avoid late nitrogen and shelter young trees from cold wind. Check for hoppers, weevils and fruit fly. A mature tree can grow large, since unpruned trees may reach 30 to 100 feet, so regular pruning keeps it manageable and productive.

ALSO READ: 35 Types of Mangoes Explained (With Pictures, and Care Tips)

How to Prevent Most Mango Tree Problems

Prevention costs far less than cure. A few steady habits protect your tree from almost everything on this list.

• Keep the ground clean. Remove fallen fruit, leaves and dead twigs weekly.
• Prune every year. An open canopy dries faster and resists fungus.
• Feed and water wisely. Use a soil test, avoid extremes and mulch well.
• Inspect often. Check flowers, new leaves and fruit every week in the season.
• Buy healthy trees. Choose certified, disease-free nursery stock.
• Ask locally. Your extension service knows which diseases and cultivars matter in your area.

Always read pesticide labels and follow local rules. University researchers also stress that disease control for home landscape trees is often not warranted or should not be intensive. Gentle, regular care often works better than heavy spraying.

Final Thoughts

Mango trees are tough, but they are not invincible. The 15 problems above explain most of the damage that growers see. Anthracnose and powdery mildew deserve the closest attention, with fruit flies and the seed weevil close behind.

The good news is that early detection works. A short weekly walk through your orchard can save an entire harvest. I always tell new growers that the best tool is a careful pair of eyes.

Start with sanitation, pruning and watching the flowers. Add targeted treatments only when needed. With patience and consistency, your trees can reward you with sweet, healthy fruit for many years.

References

1. University of Florida IFAS Extension. Mango Growing in the Florida Home Landscape (MG216): https://edis.ifas.ufl.edu/publication/MG216
2. University of Florida IFAS Extension, St. Lucie County. Mango Anthracnose and its Management: https://blogs.ifas.ufl.edu/stlucieco/2023/02/14/mango-anthracnose-and-its-management/
3. University of Hawaii at Manoa, CTAHR. Mango Diseases and Their Control (Nishijima): https://www.ctahr.hawaii.edu/oc/freepubs/pdf/hitahr_04-06-93_20-24.pdf
4. University of Hawaii at Manoa, CTAHR. Crop Knowledge Master: Mango: https://cms.ctahr.hawaii.edu/ckm/Home/Crops/Fruits-and-Nuts/Mango
5. University of Florida IFAS Extension. Mango Seed Weevil, Sternochetus mangiferae (EENY-371): https://ask.ifas.ufl.edu/publication/IN666
6. University of Florida IFAS Extension. Oriental Fruit Fly, Bactrocera dorsalis (EENY-083): https://edis.ifas.ufl.edu/publication/IN240/pdf
7. USDA Agricultural Research Service. Effect of Mango Weevil Damage on Mango Seed Viability in Hawaii (Follett and Gabbard): https://www.ars.usda.gov/ARSUserFiles/20400505/mswseedviable.pdf