Current status of angular leaf spot (Pseudomonas syringae pv . lachrymans) of cucumber: a review

Abstract

Angular leaf spot (Pseudomonas syringae pv. lachrymans) is more or less prevalent in almost every cucumber growing area of the world causing heavy losses not only to cucumber but to other cucurbits as well. Under natural conditions, the disease initially appears as minute water-soaked spots on leaves, which became and turn light tan in colour. With the passage of time, spots turn necrotic and many of these slough-off giving leaves a tattered appearance. The spots on infected fruits lead to rot or misshapening of fruit in case of severe infection. Both naturally infected as well as the artificially inoculated seed can harbour the pathogen beyond two sowing seasons. Pathogen survives on diseased crop debris buried or kept on soil surface from harvesting to next sowing time. The disease is controlled by hot water treatment, chemical seed treatment, foliar sprays and use of systemic resistance inducers.