Nitrogen application accelerates the downy mildew disease severity with leaf age in canola plants

Haq, M. E. ul, Kamran, M., Sahib, A., Yaseen, M., Anwar, M. F., Abbas, H., Chand, S. A., Hameed, A., Rashid, A., Khan, Q. A. T., Shahbaz, M. U., Abbas, W., and Ali, S.
(2021) Archives of Phytopathology and Plant Protection, 54, (19-20), 1569-1577


Downy mildew is a devastating disease of canola. Two years study was conducted to find the impact of different nitrogen levels on disease severity of downy mildew with respect to leaf age on canola plants in field conditions. Three nitrogen levels (11.50???Kg acre???1, 23???Kg acre???1 and 34.5???Kg acre???1) were applied in soil when plants were 40???days old. In control, 0???Kg acre???1 N was applied. The diseased leaves from the lower, middle and upper part of the plant were tagged and data were recorded after 10???days interval. Disease severity differed significantly between the two experimental years. A significant increase in disease severity was recorded with leaf age irrespective of the N concentration applied. Nitrogen concentrations significantly accelerated the disease severity with the increase of age. Maximum disease severity was recorded in 34.5???Kg acre???1 N applied 100???days old leaves in both experimental years.