Annual Research Symposiums (2014 onwards)

DESIGN, DEVELOPMENT, AND EVALUATION OF AN IOT- BASED AUTOMATED CENTRALIZED MUSHROOM GROWING MEDIA STERILIZATION UNIT

2025-11-27T06:09:18Z

DESIGN, DEVELOPMENT, AND EVALUATION OF AN IOT- BASED AUTOMATED CENTRALIZED MUSHROOM GROWING MEDIA STERILIZATION UNIT Wickramasooriya, H.G.S.C; Weerasooriya, G.V.T.V.; Kahandage, P.D.; Kosgollegedara, E.J.; Manawaduge, S.R. Sterilizing the substrate is crucial in artificial mushroom cultivation. In the small- scale mushroom industry in Sri Lanka, a basic steel barrel apparatus is commonly used for this purpose. Despite having more advantages, the Centralized Sterilization System (CSS), involving a central boiler and Lateral Sterilization Units (LSUs) is rarely adopted, as it demands higher attention to sustain the necessary conditions. Hence, the study aimed to improve CSS efficiency by integrating automation and IoT technology. The designed CSS included a boiler, four LSUs, a rice husk furnace, an automated husk feeding mechanism, temperature pressure sensors, with all controlled by an IoT unit. The rate of husk- feeding and airflow to the furnace is regulated based on the pressure and temperature values of LSUs. The IoT unit enables continuous monitoring and remote operation. The evaluation of CSS performance involved varying the number of LSUs, (T1- One LSU, T2- Two LSUs, T3- Three LSUs, T4 - Four LSUs). The maximum temperature and pressure of the system with all the LSUs recorded were 1030C and 68947 Pa, respectively. The duration to reach maximum pressure and temperature, duration for sterilization, and amount of fuel consumption were evaluated. The duration to reach the maximum conditions significantly increased with the number of treatments (p≤0.05). The duration for sterilization significantly increased with the number of treatments (p≤0.05). Nevertheless, no significant difference between T3 and T4 (p≥0.05). Moreover, the fuel consumption was significantly different among all treatments while the lowest and highest fuel consumption was recorded for the T1 (12.78 kg) and T4 (50.85 kg), respectively. Furthermore, the cost-benefit ratio was comparatively lower in T3 than in other treatments. Therefore, it could be concluded that mushroom-growing media sterilization with three LSUs is the most economical method in CSS with IoT technology.

ORIENTATION OF Tribolium castaneum (Coleoptera: Tenebrionidae) ADULTS TOWARDS TRAPS HAVING AGGREGATION PHEROMONE AND KAIROMONE FOLLOWING PRE-EXPOSURE TO ABAMECTIN

2025-10-10T03:06:06Z

ORIENTATION OF Tribolium castaneum (Coleoptera: Tenebrionidae) ADULTS TOWARDS TRAPS HAVING AGGREGATION PHEROMONE AND KAIROMONE FOLLOWING PRE-EXPOSURE TO ABAMECTIN Senevirathne, W.M.S.S.; Premathilaka, P.A.P.I.; Egodawatta, W.C.P.; Wijayaratne, L.K.W. The red flour beetle, Tribolium castaneum, is frequently found in stored food. Correct monitoring is a pre-requisite to precisely decide the population density and the correct timing for the management practices. DOME traps containing its aggregation pheromone 4,8-Dimethyldecanal (4,8-DMD) and commercially-available kairomones are used for this, but low trapping is often reported. Previous studies reported enhanced trapping of T. castaneum by pre-exposing to certain chemicals but no such effects of abamectin is known. This research aimed to determine the effect of abamectin on orientation of T. castaneum to traps containing its aggregation pheromone and kairomone. Tribolium castaneum 100 adults pre-exposed to a concentration series of abamectin were used 14 days following exposure. In a rectangular experimental arena (2.6 m×2 m) inside a room, six dome traps containing pheromone only (experiment 1) or a combination of pheromone and kairomone (experiment 2) were placed. After one hour, insects were released at the centre and those trapped inside each trap were counted after two hours. For pheromone alone, the highest trapping (29%) occurred in insects pre-exposed to 1 ppm abamectin (F7,24=16.29, p<0.0001) which did not significantly differ from 0 ppm and 2.5 ppm. The lowest trapping (8%) occurred at 15 ppm and was not significantly different with 20 ppm exposure. When pheromone and kairomone used together, the highest trapping (48.75%) was obtained in adults pre-exposed to 0 ppm (F7,24=165.95, p<0.0001) which was not significantly different with 2.5 ppm exposure while the lowest 11% obtained with 20 ppm abamectin. More insects were trapped in the combination of pheromone and kairomone than pheromone alone. But pre-exposure to high concentrations of abamectin reduced trapping at 14 days following exposure. Future research needs to schedule the pre-treatment with abamectin so that it would not jeopardize monitoring efforts using pheromone and kairomone traps and thus ensuring the protection of stored food from insect infestation.

THE FATE OF SOIL-INOCULATED ACTINOMYCETES IN RICE RHIZOSPHERE AND RHIZOPLANE

2025-10-10T03:04:29Z

THE FATE OF SOIL-INOCULATED ACTINOMYCETES IN RICE RHIZOSPHERE AND RHIZOPLANE Samarasinghe, S.A.U.D.; Perera, H.D.D.; Padmathilake, K.R.E.; Costa, De D.M. Actinomycetes, filamentous Gram-positive bacteria, play a vital role in the rhizosphere by fostering plant growth through diverse mechanisms, such as nutrient solubilization, synthesis of plant growth-promoting hormones, and acting as antagonists of plant pathogens. Ten rhizospheric actinomycete isolates (T1-T10) which were confirmed for their capacity to fix nitrogen and solubilize phosphate in vitro were tested for their survival in paddy soil after inoculation. A pot experiment was conducted in a completely randomized design using three replicates per treatment under greenhouse conditions. Two-week-old rice seedlings (Bg 360) were grown in pots with sterilized paddy soil and then inoculated either separately with ten isolates or collectively as a consortium of all ten isolates. All eleven treatments were tested compared to the non-treated control. Starch casein agar medium supplemented with nystatin and nalidixic as the antibiotics was used to enumerate actinomycetes in paddy rhizosphere and rhizoplane following the dilution plate technique with enumeration was conducted up to eighth-week post-inoculation. Growth parameters including root volume, shoot length, and dry and fresh weights of shoots and roots were measured in the sixth week after seeding. Statistical analysis for both parametric (ANOVA) and non-parametric (non-parametric ANOVA) methods was performed using SAS Studio. Results revealed a decline in colony-forming units (CFUs) for all isolates except T3 and T11 over time in both rhizoplane and rhizosphere. However, T3 and T11 did not exhibit a significant reduction in CFUs (p>0.05) in the rhizosphere throughout the study. Rice plants inoculated with T3 exhibited significantly higher performances for all tested growth parameters. The root volume was elevated in both treatments inoculated with T3 alone, and those inoculated with the consortium. In conclusion, this study underscores the importance of the T3 strain and consortium comprising all ten isolates of actinomycetes in promoting plant growth performance, highlighting their potential for application in rice cultivation.

IDENTIFICATION OF ABIOTIC STRESS-TOLERANT RHIZOBIAL STRAINS INHABITING Mimosa pudica IN ANURADHAPURA DISTRICT, SRI LANKA

2025-10-10T04:02:03Z

IDENTIFICATION OF ABIOTIC STRESS-TOLERANT RHIZOBIAL STRAINS INHABITING Mimosa pudica IN ANURADHAPURA DISTRICT, SRI LANKA Maniyangama, M.R.T.N.K.; Padmathilake, K.R.E.; Rajapakse, S. Biological nitrogen fixation by symbiotic relationship of legumes and rhizobia enhances soil fertility. These rhizobia also exhibit tolerance to a range of abiotic stresses including salts, drought, extreme pH, and heat. Mimosa pudica, (family Fabaceae), a problematic weed, is a nitrogen fixing herb even in extreme and resource-limited environments. Stress tolerant rhizobial populations inhabiting M. pudica can be a vital solution to enhance nitrogen fixation under harsh environmental conditions. The current study aimed to screen stress tolerant rhizobial isolates inhabiting M. pudica growing in selected locations of Anuradhapura district. Live root nodules of M. pudica were collected from six sampling locations and symbiotic rhizobial isolates from root nodules were cultured on ½ Lupin agar medium. To test the tolerance for stress conditions isolates were inoculated to ½ Lupin broth. The growth of 30 isolates was assessed using spectrophotometric absorbance after subjecting three consecutive days to extreme conditions of pH (3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0), salinity (NaCl concentrations 0.1%, 1%, 1.5%, 2%, 2.5%, 3%), temperature (25℃, 30℃, 35℃, 40℃, 45℃), and drought stress (polyethylene glycol 8000 concentrations 0.1% to 0.4%), respectively. Ten isolates; Al-c, Al-d, Md-c, Md-e, Th-d, Ka-a, Ka-b, Ka-c, Ke-c, and Ke-d, were screened based on their survivability under extreme individual stress conditions. Afterwards, screened isolates were exposed to a combination effect of temperature (36℃) and drought (0.3%) and, Md-c, Th-d, Ka-c, Ke-c and Ke-d exhibited significant tolerance (p<0.05). The possibilities of cross inoculation of these isolates may enhance the production of legume crops under stress deprived conditions and may also serve as a potential biofertilizer in marginal conditions.