4.Journals Published in Sri Lanka
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Item Impact of soil moisture on growth , yield and nodulation of Mung bean (Vigna radiata) growing in the Yala season on non calcic brown soils(Postgraduate Institute of Agriculture, University of Peradeniya:Peradeniya, 2008) Kulathunga, M.R.D.L.; De Silva, S.H.S.A.; Sanagakkara, U.R.Item Effect of different levels and frequency of nitrogen application on the nodulation of groundnut(Arachis hypogea L) in regosols(Eastern University. Chenkalady, 1999) Thanaraj, T.; Sandanam, S.Item Cross inoculation of Bradyrhizobia among three common legume cover crops in rubber plantations of Sri Lanka(Rubber Research Institute. Agalawatta, 1989) Jayasinghe, C.K.; Wettasinghe, S.Mixtures of legume cover crops are common in rubber plantations of Sri Lanka during the immature phase of rubber, and changes in ther composition occure with the changes in environment conditions due to the growth of canopies in rubber plants. Bradythizobial isolates from Pueraria phaseloides and desmodium ovalifolium were able to nodulate both legumes, but non of the isolates, including CB 756 (C.S.I.R.O collection, Queensland) produced nodules on Mimosa invisa.Item Seasonal variations in nodule activity of Pueraria phaseoloides (Roxb) Benth(Rubber Research Institute. Agalawatta, 1990) Jayasinghe, C.K.; Parker, C.A.; Kulasooriya, S.A.The age of Pueraria phaseoloides plants had a marked effect upon the rate of acetylene reduction in their nodules. Acetylene reduction activity increased with the age of the plant and maximum efficiency of nodule activity was detected 60 days after sowing, followed by a marked decline on the 120th day and continued at a low rate. Dry matter yield and total nitrogen in plants was more or less constant thrugh out the assay period.Item Effect of combined nitrogen on nodule function of leguminous crops with special reference to tropical soils(Rubber Research Institute. Agalawatta, 1991) Jayasinghe, C.K.The effect of combined nitrogen on nitrogen fixation has been discussed by several investigators and from their findings it could be concluded that inorganic nitrogen may have either stimulatory, neutral of negative effect on nitrogen fixation depending on the type of legome and soil condition. It was reported in some instances that low levels of combined nitrogen especially when applied as a "Starter" fertilizer at germination, stimulates plant growth and enhances nodule mass and nitrogen fixation. On the other hand when most of the legumes are grown in soil high in available nitrogen, the nitrogen fixation rate is severely affected. This phenomenon may become more critical when legumes are grown as cover crops where non legume counterpart is fertilized with nitrogenous fertilizer. The degree of inhibition appears to vary with sevaral factors vis, concentration of combined nitrogen, host species, cultivar, strain of root nodule bacteria, rate of inculation, light intensity and temperature. However, the most critical factor is the concentration of combined nitrogen and it has been shown that very low concentrations such as 240 ppm N reducedItem 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 nitrogen