Deodara is not a hardy tree here in the Midwest, yet I would suspect the white substance is that of tree sap that is typical of many evergreen trees. Potential causes could be a canker or feeding activities of migrating birds called Sap Suckers. Damage is caused by the creation of a series of holes which weep and is consumed as food by the birds. Migratory birds are normally protected by law. Consult with your local Extension Service for a more locally and focused response.
