About DIEBACK DISEASE(UPSC)

Context: The disease posing a threat to the neem trees has been identified as twig blight and dieback disease in Telangana

Details:

Neem shows antibacterial, antifungal, and other versatile properties, but it does not exempt the neem trees from being attacked by pests and diseases.
It has become a familiar sight in Telanganaand also in some other southern states over the last few years that twigs and leaves of neem trees dry up.
The dieback disease affects leaves, twigs and the inflorescence of neem trees of all ages and it causes almost 100% loss of fruit production in severely infected trees.
The dieback disease was first reported in the country during the 1990s near Dehradun in Uttarakhand, while it was first noticed in Telangana in 2019.
Since it was first detected three years ago, the disease had waned but resurfaced in Telangana this time around.

The dieback disease is mainly caused by the fungi Phomopsis azadirachtae.
The appearance of symptoms starts with the onset of the rainy season and becomes progressively severe in the later part of the rainy season and early winter.
The dieback is a fungal disease but the neem trees are sometimes hit by insect infestation and the combination of both increases its impact.
Though neem trees are strong enough to combat the damage caused by the disease, measures to control its spread can be undertaken at community level for better results.
To control the disease, the twigs affected by the disease should be cut and a blend of fungicide and insecticide can be sprayed after their removal.
Alternatively, a pit should be dug around an affected tree, and water mixed with fungicide and an insecticide should be poured into it.