Symptoms of bacterial blight appear first on leaves as small, irregularly shaped, water-soaked spots. They vary from 2 to 5 mm in diameter and have necrotic centers. The water-soaked spots, when viewed against light, look translucent. They turn light brown gradually and then dark brown and are surrounded by prominent water-soaked margins. Severely affected leaves become yellow and are easily shed. Bacterial ooze is sometimes found in the centers of the spots.
Dr. V. I. BenagiProfessor and Head, Department of Plant Pathology, UAS, Dharwad – 580 005, Karnataka, India
Host: Pomegranate (Punica granatum L.)Disease name: Bacterial blight of pomegranatePathogen name: Xanthomonas axonopodis pv. punicae
Bacterial blight of pomegranate was first reported in India from Delhi in 1952 and was of minor economic importance until 1998. Presently, the disease occurs widely and outbreaks have been recorded in all major pomegranate-growing states including Maharashtra, Karnataka, and Andhra Pradesh. Losses caused by bacterial blight were recorded in Hanumangarh district of Rajasthan in 2009. Until recently, the disease was prevalent only in India, but it was also reported from South Africa in 2010. Bacterial blight of pomegranate affects leaves, twigs, and fruits. Infected fruit and twigs are potential sources of primary inoculum. The secondary spread of bacterium is mainly through rain and spray splashes, irrigation water, pruning tools, humans, and insect vectors. Entry is through wounds and natural openings. The first water-soaked lesions develop within 2–3 days and appear as dark red spots. Disease buildup is rapid from July to September. Severity increases during June and July and reaches a maximum in September and October and then declines. Bacterial cells are capable of surviving in soil for >120 days and also survive in fallen leaves during the off-season. High temperatures and low humidity or both favor disease development. Optimal temperature for growth of bacterium is 30°C; thermal death point is about 52°C.
Picture your photograph as the APS Featured
Click here to find out more
License to Copy. This
notice hereby grants permission to APS users to copy the image featured for
noncommercial, personal use. All components of APSnet are copyrighted and may
not be reproduced or distributed except by express permission of APS. Copyright
is not claimed for material provided by United States government employees as
part of their work. APS copyright extends to images, text, graphics,
photographs, illustrations, audio, video, computer software, and all other
elements of the site.Instructions to Copy. For PC, position your mouse
cursor on the featured image, click the right mouse button, and choose "Save
Picture As..." or "Save this Image as..." whichever is the case. For Mac, click
the only mouse button and follow the same steps. Users may want to set up a
specific directory and file naming scheme for storing images; otherwise, they
will be saved using your system defaults. Images may be used in any software
application that supports JPEG file format or viewed in an Internet browser as
Get ALL the Latest Updates for CHANGING LANDSCAPES OF PLANT PATHOLOGY. Follow APS!