This book tells about the results of evaluation of resistance against diseases of Dalbergia sissoo and Eucalyptus species raised in the field under under tree improvement programme with different clones. The study has brought out useful information of practical application in field about the disease resistant and susceptible clones of Dalbergia sissoo and Eucalyptus. In disease prone areas resistant clones should be used for plantations for obtaining desired growth and yield. Since breeding for disease resistant plants for forest trees is time consuming unlike agriculture plants, identifying disease resistant material and propagating them is the best bet.The methodology developed in the study can be used for identifying disease resistant clones for other tree species as well. The information can well be used for the identification of disease resistant genes using molecular technology and introducing them using somatic hybridization and recombinant DNA technology for developing disease resistant seeds/embryos. Hybridization programme can be followed for developing disease resistant hybrids by crossing better form parents and disease resistant poor form parents.