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Non-Pests > Physiological responses > Black marks on guava fruit, India
April 2012. Black marks around the lower part of the fruit from Orissa, India. What are they?
One suggestion was that the discolouration was caused by Glomerella and in support of this a page was sent from Weber (1973) Univ. of Florida, entitled Bacterial & Funga Diseases of Plant in the Tropics. However, in that case there were lesions on the fruit, but the fruit from India do not show any such infections.
[Editor, there are similar blackening on leaves in yam. It would be of interest to take a slither of the skin of the fruit and clear it in lactophenol to see if germinating spores of Colletotrichum are present. The presence of spores and a rection to light is the cause of the blackening of yam during epidemics of the fungus.]