Powdery Mildew of Mango Control

Symptoms

Caused by the fungus Oidium mangiferae. A white powdery growth covers flower panicles, tender leaves and young fruit. Affected flowers dry and drop, panicles look greyish white, and tiny fruits blacken and fall. It strikes most during dry cool weather with morning mist at flowering.

Damage

Powdery mildew is one of the most destructive flowering stage diseases of mango. By killing flowers and young fruit it can cause very heavy fruit set loss, sometimes nearly total in a bad season. It is especially damaging in north Indian belts with cool misty flowering weather.

Organic & cultural control

Wettable sulphur is the classic low cost control and is sprayed at panicle emergence and repeated as flowering advances. Keep the canopy open for air movement. Avoid sprinkler irrigation at flowering. Monitor panicles closely from bud burst so the first spray goes on before the powder spreads.

Chemical control

Where pressure is high, systemic fungicides such as hexaconazole, dinocap, tridemorph or a triazole are sprayed in rotation with sulphur, with two to three sprays from bud burst to fruit set; rotating groups prevents resistance. Always read and follow the label, observe the pre-harvest interval, avoid sulphur in very hot weather, and consult your KVK or agronomist.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Plant less susceptible varieties and prune for an open airy canopy. Begin protective sprays at bud burst rather than waiting for visible powder, because timing the first spray early is the key to control. Remove and destroy badly infected panicles, and avoid wetting foliage during flowering.