Algal rust: It is caused by an algal parasite Cephaleuros mycoides. The disease first appeared on the young unfolded tender branches. On the infected young leaves, small lesions of velvety white growth appear on the lower surface. On the upper surface, just the opposite site of the lesion, chlorotic patches occur. As the leaves unfold and increase in size, the velvety growth becomes more prominent and dense. Later larger areas of leaves are affected with this growth. Old and thick leaves show various types of malformation.