Volume 14 - Issue 2 - 2015

“Should ‘Paraviwella Beach’ in Sri Lanka be Preserved for ‘Sea Bathing’?”: A ZTCM Approach

2015-12-01T00:00:00Z

“Should ‘Paraviwella Beach’ in Sri Lanka be Preserved for ‘Sea Bathing’?”: A ZTCM Approach Rathnayake, Wasantha ‘Sea bathing’ is the main recreational activity at the Paraviwella Beach Park in Sri Lanka. However, there is a proposal by the Government of Sri Lanka to convert the Beach Park into an area that could be used for the expansion of the fisheries harbour. Our study examines the possibility of the proposal against maintaining the Park by using the Zonal Travel Cost Method to estimate the welfare benefits (in terms of Consumer Surplus). The study shows that the welfare benefits of Paraviwella Beach Park to be LKR 6.39 million per year for local visitors. Our results suggest that for maximum revenue from the park to be derived, the fresh water bathing fee should be raised to LKR 100.45 from the present fee of LKR 20 since those who sea-bathe requires a fresh water bath thereafter. Though it would reduce the visitor numbers to the Park by 34%, it would increase the total revenue of the Park by 231.18%. These values demonstrate that the Park can be preserved for sea-bathing while making the site more financially viable.

Application of Seed Treatments to Increase Germinability of Cardamom (Elettaria cardamomum) Seeds under in vitro Conditions

2015-12-01T00:00:00Z

Application of Seed Treatments to Increase Germinability of Cardamom (Elettaria cardamomum) Seeds under in vitro Conditions Dahanayake, Nilanthi Cardamom (Elettaria cardamomum) has great commercial value as a spice in Sri Lanka. Due to the presence of hard seed coat, cardamom has low seed germination potential. Therefore the present study was conducted to study the potential to improve the seed germination by applying different mechanical, physical and chemical treatments and to develop a cost effective and rapid seed germination method in in vitro conditions. Complete Randomized Design (CRD) with ten replicates was used for the study. The seeds of cardamom were treated with 40 different seed treatments and surface sterilized by using 20% clorex. MS basal medium was used without plant growth regulators and solidified by 0.6% agar. Anova (DMRT) test showed that there were significant effects at p<0.05 level on seed germination of cardamom seeds with different seed treatments. According to the results 50% HNO3 for 15 min exposure was the best treatment to obtain higher number of germinated seeds (90%) within 6 weeks upto 0.6 cm height. The second and third best treatments were 75% HNO3 for 15 min and 75% HNO3 for 10 min which showed 80% and 65% seed germination percentages respectively. This experiment showed chemical treatment (HNO3 ) is the best to induce seed germination of E. cardamomum in in vitro conditions. The results obtained in this study will be important for plant breeders and farmers who cultivate these species commercially.

Adsorptive Behavior of Arsenic(III) Ions from Aqueous Solution onto Forestry and Agricultural Waste Biochar Pyrolyzed at 400° C

2015-12-01T00:00:00Z

Adsorptive Behavior of Arsenic(III) Ions from Aqueous Solution onto Forestry and Agricultural Waste Biochar Pyrolyzed at 400° C Gunatilake, S.K Sorption capacity of two different biochar (saw dust and rice straw) was evaluated in the recovery of arsenic from aqueous solutions. Biochar from rice straw and saw dust were obtained from pyrolysis of biomass at 400◦ C. The optimum sorption conditions were studied for different concentrated monometallic system. Sorption studies were performed at different pH, contracting time and different initial metal ion concentration in the batch mode. The optimum pH was 3 for recovery of As(III) and kinetic studies yielded an optimum equilibrium time of 50-60 minutes with an adsorbent dose of 1 g/L and initial concentration ∼20 mg/L for As(III) ions. As(III) ions in aqueous solution were transported to biochar surface through adsorption and intra-particle diffusion process. Experimental data for As(III) ions was fitted a Langmuir model with R2 value for As(III) 0.969, 0.879 for saw dust and rice straw respectively. The Freundlich constant, KF values for removal of As(III) ions by saw dust and rice straw were 0.9127, 0.8951 respectively. The 1/n value for arsenic ions obtained from saw dust and rice straw were 0.209, 028 and indicate the normal sorption of As(III). The values indicated the affinity of the sorbent towards the uptake of As(III) ions were favorable and rice straw and saw dust biomass can be used to remove Arsenic(III) ions from aqueous phase.

Effect of pre-harvest Potassium Treatment on Stem-end Rot Disease Development of Mango (Mangifera indica L.)cv. TomEJC during Fruit Ripening

2015-12-01T00:00:00Z

Effect of pre-harvest Potassium Treatment on Stem-end Rot Disease Development of Mango (Mangifera indica L.)cv. TomEJC during Fruit Ripening Nisansala, Y.M.C; Jayakod, L.K.R.R; Sarananda, H.A; Somaratne, S Mango (Mangifera indica L.) cv. TomEJC has utmost potential in export market due to its unique quality. Post-harvest disease of mango such as stem-end rot can cause considerable losses of fruits and could therefore be considered as a great threat to local and export market. This disease is controlled by application of fungicides from the time of flowering in cultivations where this disease is severe. However, the use of fungicides could lead to hazardous effects such as oncogenic risks on the consumers. Therefore, search for alternative measures for the management of stem-end rot disease is essential. In this study, an attempt was made to find out the effect of preharvest application of KCl on controlling stem-end rot disease development of ripe fruit. KCl at concentrations of 1 gl-1, 2 gl-1 and 4 gl-1 were sprayed on fruit when fruits were immature. All fruits were bagged with paper bags and fruits were harvested at the correct maturity stage. Then all fruits were inoculated with Botryodiplodia theobromae mycelial plug and allowed for natural ripening. A significant difference was observed in fruit length, fruit width and fruit volume in KCl- treated fruits when compared to controls. Highest fruit volume was observed in 1 gl-1 KCl- treated fruits and the lowest amount of total soluble solids was observed in 2 gl-1 KCl- treated fruits. An increase in lightness and yellowness of peel color in KCl- treated fruits when compared to control II (non-inoculated, non-treated) was evident, indicated by increasing L*, b* and chroma values. However, no significant difference in hue values of peel color was observed among treatments. Flesh color showed a different response to treatments and no difference in chroma value was observed among treatments. The highest L* value and hue value was observed in 2 gl-1 KCl- treated fruits. Incidence and severity of stem-end rot was significantly decreased by 2 gl-1 KCl treatment without drastically affecting the physico-chemical properties of fruits. Vast research has shown that potassium and chloride fertility have been effective in reducing crop injury from diseases. Different mechanisms such as nutritional effects, changes of the Sabaragamuwa University Journal Volume 14 Number 2; December 2015, pp 119-132 ISSN 1391-3166; eISSN 2386-2041 DOI : http://dx.doi.org/10.4038/suslj.v14i2.7700 120 host-pathogen environment and production of disease inhibitory compounds could be some possible ways of action of both K and Cl in modifying disease resistance or susceptibility. Since 2 gl-1 KCl was able to suppress stem-end rot disease development in inoculated fruits, this concentration can be recommended as a field application to control this disease in mango variety tested after repeating the same experiment at different locations.