Abstract

Considering the drastic depletion, slow growing nature and long gestation period of Dalbergia latifolia, a nitrogen fixing as well as high valued timber yielding forest species, this study was conducted during 2001-2004 with the view of increasing its growth through various soil management practices using different types of planting materials such as root suckers, seedlings and rooted cuttings. The study also aimed at finding out the association and variability of isolate of rhizobium and the clonalpropagation in this species. Growth response to various treatments such as lime, vermi compost, cow dung, chemical fertilizer, rhizobium and combinations of organic manures with chemical fertilizer were studied by conducting pot trial at Field Research Centre of KFRI in Velupadam and field trial at Sub Centre of KFRI in Nilambur. Changes in soil properties due to the application of various treatments were also studied. Results indicated that organic manures such as cow dung (1kg/plant) or compost (1kg/plant) either alone or in combination with chemical fertiliser (« kg cow dung or « kg compost + potash-15g + amophos-50g) were effective in achieving a substantial increase in the growth of Dalbergia latifolia coupled with improvement in soil quality. Allthe three types of planting materials used in the study responded very well to the above treatments and the maximum growth responses were observed in root suckers followed by seedlings and cuttings. The best strain of rhizobia was isolated from those collected from Nilambur and all the cultures were capable of forming nodulation on Dalbergia seedlings. But the application of these rhizobia had no significant impact on the growth of Dalbergia latifolia. In order to produce rooted cuttings from suckers the best concentration of IBA was 5000 ppm