Status and symptomatology of die-back and twig blight diseases of almond (Prunus amygdalus Batsch.) in Kashmir valley.

Abstract

Die-back and twig blight are the most important diseases of almond (Prunus amygdalus Batsch.) plantation world wide. Survey of almond orchards in Budgam and Pulwama districts revealed the presence of both the diseases with varying degrees of incidence and intensity. On an overall basis die-back recorded the maximum disease incidence and intensity of 22.70 and 10.37 per cent respectively, while incidence of 16.45 per cent and intensity of 7.61 per cent for twig blight. Highest die-back incidence (26.15%) and intensity (11.96%) was recorded in district Budgam while, that of twig blight, 19.85 and 9.12 per cent in incidence and intensity, respectively was also recorded in the same district. Die-back disease was initially characterized by the appearance of light brown lesions on terminal bud scales of current season growth in the first week of June resulting in yellowing and drooping of terminal leaf lets. Later on small light brown lesions appeared on lateral buds which iniciated the chlorosis and necrosis of terminal twig portion. Subsequently progression of chlorosis and necrosis in dawn-ward direction continued throughout the growing season resulting in shriveling and collapsing of the effected twigs. Twig blight initially manifests as minute water soaked lesions near the base of leaf petioles on current seasons terminal growth during 2nd week of June. Elongation of the lesions both in up-ward and down-ward direction along the twig axis resulted in the formation of sunken streaks causing twig girdling. The leaves over the girdled twig wilted and remained clinged unless disturbed through strong breeze or mechanically.