Dr. SURYANARAYANA V.NAGARJUN N2018-05-292018-05-292015-06http://krishikosh.egranth.ac.in/handle/1/5810048111Disease cause nursery damage by seedling mortality, premature defoliation, growth and vigor loss and stressing an attention of plant growers for effective management strategies. In this line, the investigations on “Documentation of pathogenic spectra of forest nursery diseases and their management in Honnavar Division of Canara Circle” was carried out at College of Forestry, Sirsi during 2013-2015. Disease survey in nine nurseries of Honnavar Forest Division revealed 52 diseases on 50 hosts. The major diseases were leaf spot, leaf blight, leaf rust, powdery mildew and tar spot. Tar spot of Dalbergia latifolia recorded highest Per cent Disease Index (PDI) of 67.53 per cent followed by leaf spot and blight of Pongamia pinnata (66.09%), leaf spot of Syzygium cumini (63.97%) and least was by leaf spot of Machilus macarantha (1.16%). Pathogenic spectra through tissue isolation of diseased samples showed 49 pathogens to cause 52 seedling diseases on 50 different hosts. Ten pathogens are new records viz., 4 leaf spot causing ones’ as Dothiorella lopopetalum sp.nov., Lopopetalum weightianum, Rhizosphaera madhuca sp.nov. in Madhuca indica; Readeriella syzygium sp.nov. in Syzygium lanceolata. Four leaf blight causing one’s as Hormocephalum calamae sp.nov in Calamus nagabettai; Coniothyrium dalbergia sp.nov. in Dalbergia latifolia, Microsphaeropsis pongamia sp.nov. in Pongamia pinnata, Rhizosphaera pterocarpus sp.nov. in Pterocarpus santalinus, Dothiorella swietenia sp.nov. in Swietania mahagoni and Rhizosphaeria tectonia sp.nov. in Tectona grandis. In in vivo nursery disease management with nine treatments, Carbendazim (0.1 %) was highly effective in controlling five diseases (leaf blight of Pterocarpus marsupium, Tectona grandis, Sweitania mahagoni, and leaf spot of Syzygium cumini and Terminalia alata) followed by 0.1 per cent Propiconazole (tar spot of Dalbergia latifolia, leaf blight of Pongamia pinnata); 0.1 per cent Difenconazole (leaf blight of Acacia auriculiformis and leaf and tip blight of Lagerstromia lanciolata) and 0.1 per cent Mancozeb (leaf blight of Pterocarpus santalinus).ennullThesis