Studies on bacterial canker of mango.
Shekhawat G. S., Patel P. N.
Author Affiliation: IARI, New Delhi, India.
Zeitschrift fur Pflanzenkrankheiten und Pflanzenschutz 82 : 129-138
Abstract : Pseudomonas mangiferae-indicae produced water-soaked spots turning into typical cankers on mango fruits, leaves, stalks and branches under natural infection. Hence the name bacterial canker was suggested for the disease in place of leaf spot, black spot and blight. The disease was observed in 3 places on Langra and seedling cvs., affecting 10-85% of fruits. In an experimental orchard, the maximum fruit infection was in hybrids (10-100%) followed by Bangalora (40%), Neelum (5%) and Langra (2%). Of the diseased fruits 20-26% developed rotting before harvest and 20-47% during ripening. The disease remained dormant during November-March due to low temperatures (11,8-22,0 deg C), and leaf-cankers were considerably reduced because the diseased leaves fell. The twig cankers persisted and could initiate fruit infection by the end of April, while the weather was still dry. The disease spread rapidly during rains and became severe in July-August. The fruits in bunches were more vulnerable at contact points. The disease severity on leaves and fruits was not correlated. The cvs. Bombay Green, Dusheri, Chowsa, Kishan Bhog, Machhali, Fajri, Rataul, Summerbehist Alidag and Sefeda Local were free from the disease in nature but on inoculation only Bombay Green was resistant. Baneshan, Khasulkhas, Totapari, Bangalora and Langra were highly susceptible. Fytolon (0.2%), ziram (0.1%), streptomycin sulphate (0.01%) and fytolan + streptomycin sulphate (0.2+0.01%) did not protect the fruits. Seedling certification and orchard sanitation are suggested to prevent the disease.