Browsing by Author "Pahalawattaarachchi, V."

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    A Comparative Study on Culture of Kappaphycusalvarezii Using Cage Culture and Monocline Culture in Kiranchi Bay, Kilinochi.
    (Uva Wellassa University of Sri Lanka, 2012) Ganesalingam, Z.; Jayamanne, , S.C.; Pahalawattaarachchi, V.
    Kappaphycusalvarezii is economically important red tropical seaweed with a high demand due to containing polysaccharides in its cell wall and being the most important source of n-carrageenan in the world. The market for carrageenan grows rapidly since current sources of cultivated eucheumatoids seems incapable of meeting the high demand, at least in quality, price and volume for the requirements of the processing industry. Commercial cultivation of K. alvarezii was developed in the Philippines during the latter half of the 1960s using local varieties selected from the wild in comparison to different culture method practices of Kappaphycusalvarezii. The present study was conducted to find out the method more suitable for culturing K. alvarezii in Sri Lanka. Two culture systems, cage culture and monocline culture was conducted at Kiranchi Bay, Kilinochchi for a period of two months using cage culture and monocline method. Healthy seeds were collected from an existing cage culture and propagates approximately 100 g in weight were chosen. In monocline culture, the propagates were tied into nylon lines about 4 meters apart and anchored to the substratum at 25 cm intervals. In total, 75 kg were tied to monocline. In cage culture, cages of 1.5 m long x 1 m wide x 0.5 m height were placed in the bay. The cage frame was covered with mesh and K. alvarezii were tied in parallel lines. Data on initial weight, and weekly weights were taken every week and their growth was measured. The results showed that K. alvarazii gained 58% of initial weight within 2 months in monocline culture while 68% in cage culture. It was noted that the nutrients (Nitrite, Nitrate and unionized Ammonia did not show a significant difference (P>0.05) during the study period in the two culture sites. The growth rate of K. alvarezii is good in Kiranchi bay using both methods are encouraging and further studies may be required to establish culture.
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    Development of Liquid Fertilizer from Brown Seaweed-Surgassum sp
    (Uva Wellassa University of Sri Lanka, 2012) Thilakarathne, W.M.N.; Pahalawattaarachchi, V.; Jayamanne, S.C.
    Seaweeds are macroscopic marine algae which mostly visible with naked eye, photosynthetic and eukaryotic organisms. Sri Lanka has many varieties of marine algae and about 340 seaweed species (Durairatnam, 1961) that has a high potential to add value. Unfortunately exploitation and utilization of seaweeds is at a minimum level in Sri Lanka. The developments of Seaweed Liquid Fertilizer (SLF) from brown seaweed (Sargassum sp.) contribute scientifically and technologically to add value to seaweeds in Sri Lanka. SLF contain macro nutrients, trace elements, organic substances, and plant growth regulators such as auxin, cytokinkin and gibberellins (Thirumaran et at., 2009) and are important for plants to increase the yield of crop plants, increase nutrient uptake from the soil, enhance water retention capacity of soil and act as a soil conditioner. The present study is the first attempt in Sri Lanka to develop a Liquid fertilizer using seaweeds.
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    Optimization of Available Agar Processing Methodologies of Gracilaria verucosa in Kinniya
    (Uva Wellassa University of Sri Lanka, 2012) Yalinee, M; Jayamanne, S.C.; Pahalawattaarachchi, V.
    Seaweeds in Sri Lanka are mainly utilized for the production of commercially important products like agar-agar and alginic acid. Agar is commercially produced from Gracilaria and Celidiiim species (durairatnam.1962) But the gel strength is very low. This is mainly due to the processing technologies adopted and it is necessary to optimize the processing technologies to produce Agar with higher gel strength. In the present study, attempts were made to produce Agar with higher gel strength and higher yield using the species, Gracikiria verucosa.
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    Study on impacts of shade and substrates on optimum growth of micro- propagated Cryptocoryne wendtii.
    (Uva Wellassa University of Sri Lanka, 2018) Lakmali, M.T.R.V.; Coswatte, A.C.W.W.M.C.L.K.; Pahalawattaarachchi, V.; Jayamanne, S.C.
    Cryptocoryne wendtii which belongs to the Araceae family play a main role in the ornamental aquatic plant industry of Sri Lanka. Micro-propagation is used as a method for large scale multiplication of this plant. However transferring of micropropagated plants to the outer environment is challenging and needs best hardening substrate to achieve optimum growth. Therefore, this study was focused to determine the best hardening substrate and shade condition. Eight weeks old 45 plants of in-vitro rooted plants were hardened using three different substrates; coir fiber (A), clay pebbles (B), stone wools (C) and three different shades; without shade (1), 80% shade (2), 60% shade (3) for two months. Five replicates were used under different substrates and shade conditions: A(1,2,3) , B(1,2,3) , C(1,2,3). Growth performances of plants were measured using growth rates; stem length (S), root length (R), number of leaves (L) in all treatments at each substrate and shade. Collected data were subjected to statistical analysis at p<0.05. According to the results, characteristics of substrates and shade (fixed factors) significantly affect on the growth performance of C.wendtii (p<0.05). Mean stem length of plants were SA1(10.47cm+.14), SA2(9.78cm±.14), SA3(9.80cm±.14), SB1(9.74cm+.14), SB2(9.72cm+.14), SB3(10.54cm+.14), SC1(10.28cm±.14), SC2(10.10cm +.14) and SC3(10.33cm+.14) in all the treatments. Mean numbers of leaves are; LA1 (10.5±.16), LA2(9.8±.16), LA3(9.9±.16), LB1(9.7±.16), LB2(9.8±.16), LB3 (I0.5±.16), LC1(10.3±.16), LC2(10.1±.16), LC3(10.3±.16) in different treatments, while mean values of root length are recorded as; RA1(3.45cm+.16), RA2 (2.8cm±.16), RA3(2.9cm±.16), RB1(2.7cm±.16), RB2(2.8cm±.16), RB3 (3.5cm±.16), RC1(3.3cm±.16), RC2(3.1cm+.16), RC3(3.2cm±.16). The highest mean values for S, L, R were recorded by stone wool (C) substrate. The results of this study are important to achieve best growth performance of micro-propagated C. wendtii plants for ornamental aquatic plant industry.