Mango (Mangifera indica L: Anacardiaceae) is regarded as the most
liked fruit in tropical and sub-tropical regions of the world. Powdery mildew
of mango caused by Oidium mangiferae Bert. is one of the major plant pathological constraints in growing healthy
mango orchards. The apparent symptoms of the disease occurred on young tissues
of all parts of flowers, leaves and fruits. Severe blossom infection could
result in complete damage to fruit; flower failed to open and drop off from the
inflorescence. The inflorescence revealed a pattern of disease from tip to
downward and showed itself by the emergence of wefts of white mycelium on the
affected parts. Twenty-five mango varieties i.e. Langra, Dusehri, Ratole No.12, Fajri, Sindhri, Chaunsa Samar Bahisht, Anwar
ratole, Neelam, Yakta, Tota Pari, Sensation, Saroli, Malda, Ghulab e Khas,
Chaunsa Black, Chaunsa white, Anmol, Almas, Shan e Ali, Shan e Mustafa, Mahmood
Khan, Armughan, Zafaran, Malda Late and Early Gold were evaluated through the
observation of symptoms on young inflorescence to determine the disease
incidence, disease severity index and average yield of fruit. The study was
carried out in a randomized compete block design with twenty-five treatments
and three replications. The mango varieties presented different performance in
relation to powdery mildew incidence and could be categorized into eight
groups. Maximum disease incidence was observed (33.33%, 26.66% and 26.66%,
26.66%) on Dusehri, Chaunsa Samar Bahisht, Malda and Ratole No.12 respectively
and minimum disease incidence was (3.66% and 3.66%) noted on Almas and
Sensation. These two varieties showed to be tolerant against the disease. It
might be concluded that the presence or absence of symptoms caused by the
powdery mildew had no such effect on the fruit yield of the mango cultivars.