FOREST DISEASE MANAGEMENT

DISEASES OF Atrocarpus spp :

Alternaria leaf blight:
            Incidence of leaf blight disease was recorded on one month old seedlings of different species of Artocarpus raised and maintained in the IFGTB nursery, Coimbatore (Maheshwar Hegde et al., 2005). The pathogen responsible for the said disease was Alternaria sp.

Symptoms:
            Disease appears in the month of May and June and continued up to October and November. Affected leaves of A. gomezianus ssp. zeylanicus show light yellow to dark yellow coloration on the leaf tip and spreads all over lamina at the initial stage of infection.  Later the infected leaves become brown to dark brown and severely infected ones shed off.  In case of A. heterophyllus and A. hirsuta, the affected leaves show greyish white colour on the tip and spread slowly to all over the lamina.  At the advanced stage, the affected leaves are fully whitish to greyish brown and dark brown in colour. Severely infected leaves fall off and the whole plant gets dried from tip downwards later on.

Control Measures:
            Infected seedlings along with the containers should be shifted and kept in isolation in order to prevent the spread of the disease.  At the initial stage, the affected portions of the leaves can be trimmed off and foliar spray with Dithane M-45 (0.01% a.i.) can be given at weekly intervals.  Severely infected ones were treated with both foliar spray and soil drenching with Dithane M-45 (0.1% a.i.) or Fytolan (0.2% a.i.) at weekly intervals.  Afterwards, application of Biocontrol agents such as Trichoderma viride and Pseudomonas fluorescence (5 gm/ 1 litre of water) is found very effective in controlling the said disease.