'Dieback' disease plagues neem trees in Rayalaseema

Anantapur: Hundreds of neem trees in the district particularly in Gooty, Guntakal, Madakasira and Pathikonda mandals are plagued by a disease dubbed as 'dieback' by Botanists. Botanical experts Kareem Khan, principal of Kendriya Vidhyala in Guntakal and Botanist Suresh Babu, who observed the plague-hit neem trees took up the study jointly. Neem trees are highly popular in Rayalaseema districts and are used as a panacea for multiple ailments.

Twigs of Azadirachta Indica (Neem) infected with dieback were collected from different regions of Gooty, Guntakal, Maddikera and Pathikonda and they were further analysed to determine the pathogen.

Phomopsis Azadirachtae, the causal organism was isolated on malt extract agar from dieback infected neem twigs. Phomopsis genus specific primers (5.8S r-DNA) were then used for the detection of P Azadirachtae, the causative agent of dieback of neem by polymerase chain reaction (PCR). Studies revealed the amplification of expected 141 bp DNA in P Azadirachtae isolated from the diseased trees of different regions of Anantapur and Kurnool indicating the causal organism of dieback disease on neem. Studies revealed a very high incidence of dieback in most of the places of south AP. This is the first report on disease incidence of dieback of neem, says Botanists Kareem Khan and Suresh Kumar.

The dieback causing pathogen affects the apical and there by the straight growth of the main stem will be affected. This will result in the production of poor quality timber.