Diseases of fruit plantation medicinal and aromatic crops (2+1)

Bacterial canker of mango

In India it was first reported from Pune. It occurs in Bihar, Karnataka, maharastra, tamilnadu, U.P.
Symptoms

• The disease attacks the leaves, leaf stalks, stem and fruits.
• On the leaves disease first manifests itself as minute, water soaked irregular lesions, black and is surrounded by chloratic haloes.
• Due to vein limitations the spots become angular and result in cankerous patches, which sometime dry up.
• Sever infection results in defoliation. The bacteria also infects the fruits first showing water soaked lesions, which later become dark brown to black and causes sever cracking of fruits, accompanied by heavy bacterial exudation.
• There may be only a few lesions on each fruit but more lesions on tender fruits may lead to sever fruit drop.
• On branches on twigs the lesions become raised with longitudinal fissures, and are accompanied by the bacterial gummy ooze.


Etiology
Xanthomonas campestris pv.mangiferae-indicae (Patel et al.) Robbs et al. it is a gram negative rod, motile by monotrichous flagella

• Phylum:Proteobacteria
• Class:GammaProteobacteria
• Order:Xanthomonadales
• Family: Xanthomonadaceae
• Genus: Xanthomonas sp: campestris pv. mangiferae-indicae
Mode of spread and survival

• Infected nursery trees have been a major source of BBS in new orchards
• Bacterium enters the leaf through stomata and lenticels in fruit and through lenticels in twigs. The bacterium survives in infected parts on the tree.
• The pathogen survives up to 8months in the leaves. Bacteria from cankers on the twigs are the cause for primary infection on the fruits.
• Disease spread is rapid during rainy days. Disease spread to the new area through infected planting material.
• When fruits are found in bunches disease spreads when they contact each other.
Management

• Use of clean planting and grafting material and Use of certified seedlings
• Two sprays of streptocycline200-300ppm at 20days interval reduce fruit infection. Dipping the fruits in 200ppm solution of agrimycin-100 is effective.
• Mango verities like Bombay green, fazali, Jehangir and suvarnarekha are resistant.