Fig rust
Rusty pustules on the undersides of the leaves and early leaf drop тАФ a fungus driven by warm, humid, wet weather.
- Pathogen
- Fungus (Cerotelium fici)
- Spreads by
- Air-borne spores; fallen infected leaves
- Favoured by
- Warm, humid, wet weather; crowded wet foliage
- Main risk
- Early defoliation; weakened tree and crop
Overview
Fig rust, caused by the fungus Cerotelium fici, is the defining leaf disease of fig. It forms rusty, reddish-brown powdery pustules on the undersides of the leaves, with corresponding yellow spots on the upper surface. As the attack builds, the leaves yellow and drop early, so a heavily rusted tree can defoliate well before the end of the season, weakening it and cutting the crop.
The disease is spread by air-borne spores and needs warm, humid, wet weather to build тАФ so it is worst in a wet season, in humid tracts, and on crowded, still, overhead-watered trees. It is one of the main reasons fig is grown as a hot, dry-climate fruit; control rests on a dry, airy, well-drained site, sanitation, and protective fungicide sprays in humid weather.
How to identify it
- Rusty, reddish-brown powdery pustules on the undersides of the leaves.
- Yellow spots on the upper leaf surface opposite the pustules.
- Leaves yellow and drop early; a heavy attack defoliates the tree before season end.
- Worst in a wet, humid season and on crowded, overhead-watered trees.
What causes it and when
- The fungus Cerotelium fici, spread by air-borne spores and carried over on fallen infected leaves.
- Needs warm, humid, wet weather to build; worst in the monsoon and in humid tracts.
- Builds up on a dense, still canopy where the leaves stay wet.
Cultural & organic control
- Grow fig in a hot, dry, airy, well-drained site тАФ the disease is far less of a problem in a dry climate.
- Prune to keep the canopy open so leaves dry quickly, and avoid overhead watering.
- Collect and destroy fallen infected leaves to cut the carry-over of spores.
Chemical control
- Spray a recommended fungicide (mancozeb or a copper-based product) at first sign and repeat in humid weather.
- A protective spray before the wet spell beats chasing an established, defoliating attack.
- Confirm the current product, dose and interval for your area with your KVK or horticulture office.
Prevent it coming back
- Base control on a dry, airy, well-drained site and an open, pruned canopy.
- Clear fallen infected leaves each season and plan protective sprays for the humid period.
- Avoid growing fig in high-humidity, high-rainfall areas where rust is chronic.
Crops most at risk
Where this problem is called out in our crop guides тАФ open a crop for the full package of practices.
Frequently asked questions
My fig leaves have rusty spots underneath and are dropping. What is it?
That is fig rust (Cerotelium fici), the defining leaf disease of fig тАФ rusty, reddish-brown pustules on the leaf undersides with yellow spots on top, and early leaf drop that weakens the tree. Keep the canopy open and the site dry and airy, avoid overhead watering, clear fallen infected leaves, and spray a recommended fungicide (mancozeb or copper) at first sign and through humid weather.
How do I keep fig rust away?
Grow fig in a hot, dry, well-drained, airy site тАФ the disease needs warm humid weather and is far less of a problem in a dry climate. Prune to keep the canopy open so leaves dry quickly, avoid overhead watering, clear fallen leaves, and use protective fungicide sprays through any humid spell.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.