48 results
Search Results
Now showing 1 - 10 of 48
Item Effect of combined nitrogen on growth and nodule function or Pueraria phaseoloides(Rubber Research Institute. Agalawatta, 1991) Jayasinghe, C.K.; Wettasinghe, D.S.Nodulation and nitrogen fixation rates of most of the legumes are reported to be severely affected when they are grown in soils high in available nitrogen. Furthermore, this phenomenon may become more critical when legumes are grown in multiple cropping systems like Pueraria phaseoloides in rubber plantatons where ono legume counterpart is fertilized with nitrogenous fertilizer. Results of experiments conducted in seeding agar to find the effect of nitrogen on growth and nodule function of P. phaseoloides showed that nodulation of P. phaphaeoloides was inhibited at a concentration between 24.4 and 44.8 ppm nitrogenItem Cylindrocladium quinquesptatum. cultural characteristics and reproductive morphology of the clove isolate IMI 342173 from Sri Lanka(Rubber Research Institute of Sri Lanka. Agalawatte, 1996) Jayasinghe, C.K.; Wijesundera, R.L.C.Cylindrocladium quinquesptatum boeddijn and reitsma, is a destructive pathogen of eugenia caryophyllata (clove) and is identified as a potential pathogen of hevea barasiliensis in Sri Lanka. Further, the fungus infescts a number of ornamental and forest trees. We report using photomicrographs the cultural characteristics abd the morphology of the reproductive structures; condida, vesicle, stipe, phialides, chlamydospores and microsclerotia of clove isolate IMI 342173. Our investigations demonstrates that the isolate IMI 342173 from Sri Lanka resembles the isolates of C. quinqueseptatum obtained from different hosts in other parts of the world.Item Effect of incubation time on acetylene reduction activity of common cover crops of Sri Lankan rubber plantation(Rubber Research Institute. Agalawatta, 1989) Jayasinghe, C.K.; Parker, C.A.; Kulasooriya, S.A.A wide range of incubation time from a few minutes to severl hours have been used with defferent plant systems in investigations on acetylene reduction assays. However, the duration of incubation period is of utmost importance in obtaining nitrogen fixation estimates using this technology. Time course experiment showed that acwtylene reduction by nodules of P. phaseoloides and D. ovalifolium started without a lag but rate of the nitrogenasse activity was reduced 4 hours after incubation while M. invisa showed a considerable activity even at the 8th hour of incubation. In the second experiment which was conducted to observe the relationship between acetylene reduction activity and incubation time upto one our, there was a linear relationship for both P. phaseoloides (r = +0.9832) and D. ovalifolium (r = + 0.99961)Item Safe movement of rubber germplasm and precautionary measures for travellers(Rubber Research Institute of Sri Lanka. Agalawatta, 2004) Jayasinghe, C.K.Item Impact of management strategies of Hevea diseases on the environment(Rubber Research Institute of Sri Lanka. Agalawatte, 1997) Jayasinghe, C.K.; Jayaratne, R.Item Corynespora leaf spot disease of rubber (Hevea brasiliensis) - a new record(Rubber Research Institute. Agalawatta, 1986) Liyanage,. A De S.; Jayasinghe, C.K.; Liyanage, N.I.S.; Jayaratne, A.H.R.Item Check list of rubber diseases presently distributed in the world(Rubber Research Institute of Sri Lanka. Agalawatta, 2001) Jayasinghe, C.K.Item Pests and diseases of Hevea rubber and their geographical distribution(Rubber Research Institute of Sri Lanka. Agalawatta, 1999) Jayasinghe, C.K.Item First report of Colletotrichum acutatum on Mangiferia indica in Sri Lanka(2009) Jayasinghe, C.K.; Fernando, T.H.P.S.Item Guide to identification and management of diseases and other disorders in rubber plantations of Sri Lanka(Rubber Research Institute of Sri Lanka. Agalawatta, 1998) Jayasuriya, K.E.; Jayasinghe, C.K.