Mindanao Journal of Science and Technology https://mjst.ustp.edu.ph/index.php/mjst <div id="panel-7268-2-0-0" class="so-panel widget widget_heading panel-first-child" data-index="3"> <div class="thim-widget-heading thim-widget-heading-base"> <div class="sc_heading text-center"><center><strong>EDITORIAL BOARD</strong><center></center></center></div> </div> </div> <div id="panel-7268-2-0-1" class="so-panel widget widget_sow-editor panel-last-child" data-index="4"> <div class="so-widget-sow-editor so-widget-sow-editor-base"> <div class="siteorigin-widget-tinymce textwidget"> <table> <tbody> <tr> <td><img src="/public/site/images/mjst_admin/Cabahug.jpg" width="130" height="130"><br><strong>Editor-in-Chief</strong><br><strong>Ruel R. Cabahug, Ph.D.</strong><br>University of Science and Technology of Southern Philippines<br>Philippines</td> </tr> </tbody> </table> <table> <tbody> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Maglaya.jpg" alt="" width="130" height="130"><br><strong>Archie B. Maglaya, Dr. Tech.</strong><br>De La Salle University<br>Philippines</td> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Chambers.jpg" alt="" width="130" height="130"><br><strong>Therese Chambers, Ph.D.</strong><br>University of Technology<br>Jamaica</td> </tr> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Yassin.jpg" alt="" width="130" height="130"><br><strong>Mohamed Fathy Yassin, Ph.D.</strong><br>Kuwait University<br>Kuwait</td> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Oloke.jpg" alt="" width="130" height="130"><br><strong>David A. Oloke, Ph.D.</strong><br>University of Wolverhampton<br>United Kingdom</td> </tr> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Metillo.jpg" alt="" width="130" height="130"><br><strong>Ephrime B. Metillo, Ph.D.</strong><br>Mindanao State University - Iligan Institute of Technology<br>Philippines</td> <td> <p><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Reyes.jpg" alt="" width="130" height="130"><br><strong>Rosula SJ Reyes, Ph.D.</strong><br>Ateneo de Manila University<br>Philippines</p> </td> </tr> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Edwards.jpg" alt="" width="130" height="130"><br><strong>David J. Edwards, Ph.D.</strong><br>Birmingham City University<br>United Kingdom</td> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Hjorth.jpg" alt="" width="130" height="130"><br><strong>Peder Hjorth, Ph.D.</strong><br>Lund Institute of Technology-Lund University<br>Lund, Sweden</td> </tr> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Mgaya.jpg" alt="" width="130" height="130"><br><strong>Yunus D. Mgaya, Ph.D.</strong><br>University of Dar es Salaam<br>Tanzania</td> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Murad.jpg" alt="" width="130" height="130"><br><strong>Masrah Azrifah Azmi Murad, Ph.D.</strong><br>University of Putra Malaysia<br>Malaysia</td> </tr> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Albina.jpg" alt="" width="130" height="130"><br><strong>Dionel O. Albina, Ph.D.</strong><br>University of Science and Technology of Southern Philippines<br>Philippines</td> <td><img src="/public/site/images/mjst_admin/Dr._Canencia_2.jpg" width="130" height="130"><br><strong>Oliva P. Canencia, Ph.D.</strong><br>University of Science and Technology of Southern Philippines<br>Philippines</td> </tr> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Robson.jpg" alt="" width="130" height="130"><br><strong>Mark G. Robson, Ph.D.</strong><br>The State University of New Jersey<br>United States of America</td> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Bergado.jpg" alt="" width="130" height="130"><br><strong>Dennes T. Bergado, Ph.D.</strong><br>Asian Institute of Technology<br>Thailand</td> </tr> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Cultura.jpg" alt="" width="130" height="130"><br><strong>Ambrosio B. Cultura, II, Ph.D.</strong><br>University of Science and Technology of Southern Philippines<br>Philippines</td> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Parn.jpg" alt="" width="130" height="130"><br><strong>Erika Pärn</strong><br>Birmingham City University<br>United Kingdom</td> </tr> <tr> <td><img src="http://cdo.ustp.edu.ph/wp-content/uploads/2017/11/Khatib.jpg" alt="" width="130" height="130"><br><strong>Jamal Khatib, Ph.D.</strong><br>University of Wolverhampton<br>United Kingdom</td> <td><img src="/public/site/images/mjst_admin/Dr._Nwagboso_2.jpg" width="130" height="130"><br><strong>Christopher O. Nwagboso, Ph.D.</strong><br>University of Wolverhampton<br>United Kingdom</td> </tr> <tr> <td><img src="/public/site/images/mjst_admin/Dr._Raheem_.jpg" width="130" height="130"><br><strong>Shehata&nbsp;Eldabie&nbsp;A. Raheem, Dr.Eng.</strong><br>Assiut University<br>Egypt</td> <td><img src="/public/site/images/mjst_admin/Dr._Gogi_.jpg" width="130" height="130"><br><strong>Muhammad D. Gogi, Ph.D.</strong>&nbsp;<br>University of Agriculture, Faisalabad<br>Pakistan</td> </tr> </tbody> </table> </div> </div> </div> en-US [email protected] (Ruel R. Cabahug, Ph.D.) [email protected] (Mark Malinda) Thu, 22 Dec 2022 07:27:05 +0000 OJS http://blogs.law.harvard.edu/tech/rss 60 Determination of Critical Delivery Head for Hydraulic Ram Pump https://mjst.ustp.edu.ph/index.php/mjst/article/view/1330 <p><em>In response to the continuous price increase of electricity and diesel fuel, a hydraulic ram pump serves as an alternative water pump that can be useful for farmers and lowincome earning citizens living in mountainous areas. However, this pump was observed to have a critical delivery head to work uninterruptedly. This study conducted a field experiment of 10 design cases for drive pipe to determine the critical delivery head of the newly developed hydraulic ram pump using different pipe fittings and a 20-L disposable polycarbonate bottle as a pressure chamber. Results showed that the newly developed hydraulic ram pump reached its highest discharge efficiency of 12.83% and energy efficiency of 84.61% at 9.83 and 10.90 m critical delivery heads, respectively. Results also revealed that the critical delivery head was 86.27% linearly&nbsp; correlated with discharge efficiency and 46.78% linearly correlated with energy efficiency (p &lt; 0.05). Thus, the determination of the critical delivery head provided a baseline reference in ram pump studies that only gave ranges of ratios for the drive head to the delivery head. Furthermore, the newly developed hydraulic ram pump can produce water up to 700 L a day which can be beneficial for households and smallscale&nbsp;</em><em>agricultural farming.</em></p> Philip Jun S. Celerinos, Kristine D. Sanchez-Companion ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1330 Thu, 22 Dec 2022 06:45:45 +0000 Parameter Optimization for Pulp from Rice Straw and used Paper with a Box-Behnken Design https://mjst.ustp.edu.ph/index.php/mjst/article/view/1331 <p><em>In pulping process, cooking time, ethanol concentration and temperature were reported to influence pulp yield, cellulose content and acid-insoluble lignin content. In this study, the effects of the three parameters on the optimum pulp yield, cellulose content and acid-insoluble lignin content were further examined with the Box-Behnken design. This optimization aimed to discover the optimal condition for a pulping process using straw and recycled paper with ethanol concentrations of 30, 45 and 60%. As paper material, the biomass was processed with an organosolv process using ethanol as the cooking liquid to benefit almost all constituent components to obtain pulp. A quadratic model was used to assess the obtained research data. The results showed that the optimal condition comprised a cooking time of 100 min, an ethanol concentration of 60% and a temperature of 90 °C. The condition resulted in 57.59% cellulose content, 91.46% pulp yield and 41.28% acid-insoluble lignin content. </em></p> Mirna Rahmah Lubis, Lia Mairiza, Aisyah Protonia Tanjung, Nadia Yunisa Fahmi ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1331 Thu, 22 Dec 2022 06:47:05 +0000 Development and Preliminary Testing of Rotary Dryer for Plantain Flour Processing Plant https://mjst.ustp.edu.ph/index.php/mjst/article/view/1332 <p><em>Plantain postharvest losses are significant in Nigeria and efforts are focused on processing the crop into storable products to ensure its availability throughout the year. To obtain the desired flour quality and quantity, plantain must be dried for an hour at a temperature not exceeding 70 °C and then discharged without human intervention. There have been significant obstacles in plantain processing. Regular turning of plantain pulps during drying, and intimate contact between them and the hot-drying air should be ensured to retain plantain nutritional and esteem values in the flour produced. In this study, a rotary dryer was developed. The machine is capable of drying plantain within the aforementioned hour and temperature range and is suitable for use in a plantain flour processing plant. A preliminary test was conducted to assess the fabricated prototype’s functional performance and plantain particulates were able to move through the dryer. Upon varying the air-inlet aperture of the dryer from 0 to 125,680 mm<sup>2</sup>, the drying air velocity increased from 0 to 4.4 m/s. The airinlet aperture was proportional to air velocity/volume, particulate deflection within the dryer, particulate loss from the dryer and the time taken by the heater to reach the desired drying temperature. It became evident that drying air velocity/volume, deflection and particulate loss can all be influenced regardless of the blower’s speed, potentially affecting the dryer’s capacity and efficiency.</em></p> Emmanuel O. Olutomilola, Sesan P. Ayodeji, Michael K. Adeyeri, Tayo N. Fagbemi, Pius B. Mogaji ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1332 Thu, 22 Dec 2022 06:48:34 +0000 Bayesian Belief Network Modeling of Accident Occurrence in Metal Lathe Machining Operations https://mjst.ustp.edu.ph/index.php/mjst/article/view/1333 <p><em>Accidents occurrence in metal lathe machining operations in industrial workshops often cost organizations billions of dollars while injured workers and families are faced with financial and emotional burdens. Studies revealed that the fly-out accident is the most probable accident that occurs during metal lathe machining operations. The uncertainty surrounding its occurrence is rarely reported. This study, therefore, modeled the uncertainty surrounding the occurrence of a fly-out accident during metal lathe machining operations and its corresponding consequences using the Bayesian belief network (BBN). Fly-out accident causal factors were identified representing the parent nodes with two states each. Two child-node scenarios were modeled on Bayesian belief influence diagrams, namely the fly-out accident with two states (yes and no) and the consequences of the fly-out accident with three states (fatal, serious and minor). Seven causal factors of the fly-out accident were identified (chuck-related fault, tool-post failure, workpiece holding fault, coolant fault, wrong operating speed, safety-related guards fault and wrong feed rate). Bayesian causal inference of fly-out accident was 0.708 and the fatal fly-out accident was 0.263. Bayesian diagnostic inference showed that chuck association fault and improper feed rate were significant causal factors influencing the occurrence of a fly-out accident, fatal fly-out accident and serious fly-out accident, while the occurrence of a minor fly-out accident was affected by coolant fault during machining operations. The study identified areas of&nbsp;</em><em>safety concerns that may be used for the development of Machine Workshop Safety Management Systems toward sustainable, safe, and effective machine workshop operations.</em></p> Olasunkanmi O. Akinyemi, Hezekiah O. Adeyemi, Olanrewaju B. Olatunde, Olaolu Folorunsho, Muhammed B. Musa ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1333 Thu, 22 Dec 2022 00:00:00 +0000 Effect of Indigenous Processing by Obu Manuvu on the Anti-nutrient and Nutrient Factors of Taro (Colocasia esculenta) https://mjst.ustp.edu.ph/index.php/mjst/article/view/1334 <p><em>Anti-nutrient factors are secondary plant metabolites that can adversely affect the full utilization of nutrients in plant-based food products. However, the level of these antinutrients can be reduced by the application of various food processing methods. This study determined the effect of indigenous processing by the Obu Manuvu in Sitio Ladian, Marilog District, Davao City, Philippines on the anti-nutrient factors, proximate composition and mineral content of taro. The indigenous process involves soaking and boiling of taro, which is then stuffed in bamboo tubes to make ‘linutlut na gabi.’ The anti-nutrients analyzed in this study were tannin, cyanogenic glycoside and oxalate. Results showed a significant reduction amounting to 66.67, 98.08 and 91.74% for these anti-nutrients, respectively. The indigenous processing also showed a significant effect on the proximate composition of taro, specifically on the moisture (13.06% increase) and crude ash (2.45% increase) contents. For crude fat, crude fiber and crude protein contents, no significant changes were observed. For the mineral analyses, it was found that iron and manganese increased by 152.45 and 26.32%, respectively, after indigenous processing. Moreover, no significant changes were observed in the zinc and calcium contents of taro after indigenous processing. Hence, the processing method of the Obu Manuvu was effective in decreasing the anti-nutrient content, particularly tannin, cyanogenic glycoside and oxalate. This also improved the nutrient profile of taro as shown by the increase in iron and manganese. This study could be used for future dietary interventions to address issues of malnutrition and food safety. </em></p> Aaron P. Lorilla, Jennifer P. Fronteras, Belfred Bryan G. Chavez, Rovi Gem E. Villame, Pedro A. Alviola IV ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1334 Thu, 22 Dec 2022 06:51:21 +0000 Damaged Area Mapping and Ground Displacement Estimation using Sentinel-1 Synthetic Aperture Radar (SAR) Interferometry: January 12, 2020, Taal Volcano Eruption Case Study, Philippines https://mjst.ustp.edu.ph/index.php/mjst/article/view/1335 <p><em>The availability of damage assessment maps and ground displacement information is essential in the Philippines, which experiences various types of climate-induced and naturally-driven geohazards. The emergence of freely accessible space-borne synthetic aperture radar (SAR) data has led to interferometric SAR (InSAR) applications in the Philippines. However, most InSAR studies only focused on ground displacement detection, monitoring, and modeling and not on damages resulting from geohazards. This work used pre- and co-eruption Sentinel-1 interferometric pair datasets and the SeNtinel-1 Application Platform tool to create a pixel-based damage proxy map (DPM) for the 2020 Taal Volcano eruption in the Philippines, employing a coherence difference analysis. The pre-eruption coherence difference data stack mean and standard deviation were exploited to achieve a coherence difference threshold that reasonably created the DPM that delineated damaged areas, which included buildings and roads. The DPM was qualitatively evaluated through comparison with the field investigation and reports obtained from the Philippine Institute of Volcanology and Seismology (PHIVOLCS) and showed significant agreement with 89% overall accuracy. The decomposition of the line-of-sight displacement field map revealed the dynamic geological activities due to the phreatomagmatic eruption. The vertical displacements from InSAR and in-situ measurements obtained from field inspection and PHIVOLCS reports showed excellent agreement with root-mean-squared less than 2 cm and coefficient of determination (R<sup>2</sup>) close to unity. Overall, the application of InSAR to Sentinel-1 SAR images successfully mapped damaged areas and estimated ground displacements associated with the Taal Volcano phreatomagmatic eruption on January 12, 2020.</em></p> Ryan A. Ramirez, Rajiv Eldon E. Abdullah ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1335 Thu, 22 Dec 2022 06:53:34 +0000 Influence of Digester Height-to-Diameter Ratio on Biomethanation of Market Vegetable Wastes https://mjst.ustp.edu.ph/index.php/mjst/article/view/1336 <p><em>Biogas digesters are used to produce methane gas from organic wastes such as vegetable wastes. They come in different sizes and designs depending on available space, costs, type of operations and other considerations. Fifteen types of vegetable wastes from Cagayan de Oro markets were anaerobically digested in a batch-type digester with cow manure as inoculum at ambient conditions for 40 days. Five 1-L plastic cylinders with different height-to-diameter ratios (0.77, 1.08, 1.58, 1.93 and 2.80) were used as digesters to determine the effect of digester height-to-diameter ratio on methane production using these vegetable wastes. Results revealed that the digester with the lowest height-to-diameter ratio produced the most methane (53.3%) after the retention time. In contrast, the digester with the highest height-to-diameter ratio yielded the least methane concentration (46.8%). This indicated that there was an inverse relationship between the ratio and the methane production of vegetable wastes mixed with cow manure. Although the results suggested a minor influence, the statistical analysis presented an insignificant influence of the height-to-diameter ratio on the biomethanation of vegetable wastes.</em></p> Dennis E. Ganas ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1336 Thu, 22 Dec 2022 06:54:48 +0000 Regrowth of Lowland Ecotype Cyperus rotundus L. in Response to Soil Depth, Shoot Clipping and Flooding Depth Interventions https://mjst.ustp.edu.ph/index.php/mjst/article/view/1337 <p><em>Lowland ecotype Cyperus rotundus L. (LE-CYPRO) has tubers that can grow and survive under flooded conditions. However, information on the responses of its tubers to the combination of soil depth or shoot clipping with flooding is unavailable. Two experiments were conducted to determine the germination and regrowth of LE-CYPRO tubers in response to soil depth, shoot clipping and flooding depth interventions. Experiment 1 involved pre-sprouted (PS) and non-sprouted (NS) tubers subjected to three soil depths (0, 5 and 10 cm) and three flooding depths (0, 3 and 5 cm); Experiment 2 used PS tubers subjected to shoot clipping at periods of 10, 20 and 30 days after planting (DAP) under three water conditions (saturated, early flooding and late flooding). Irrespective of soil depths, PS and NS tubers had 100% germination and regrowth without flooding (0-cm flooding depth). When planted at the soil surface (0-cm soil depth) and flooded by 3- to 5-cm, only 50 and 40% of PS while 20% of NS tubers germinated. No germination was seen on tubers buried under 5- to 10-cm soil depths and flooded by 3- to 5-cm depths. Revived PS tubers buried and flooded for 100 days at 0-, 5- and 10-cm depths had 20 to 60% germinations at 3-cm flooding depth&nbsp;</em><em>and 20 to 70% at 5-cm flooding depth; NS tubers had 40 to 50% germinations at 3-cm flooding depth and 40% at 5-cm flooding depth. Growth variables of the weed at shoot clipping periods of 10, 20 and 30 DAP were comparable to the control under saturated conditions. Growth variables were reduced by 68 to 97.3% and 21.7 to 100% when aided by early and late flooding, respectively. This information could be used in the formulation of effective and comprehensive weed management for LE-CYPRO.</em></p> Dindo King M. Donayre, Jobelle S. Bruno, Anna Maria Lourdes S. Latonio, Jessica Joyce L. Jimenez, Edwin C. Martin ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1337 Thu, 22 Dec 2022 06:56:03 +0000 Improving the Yearly Profit of Wind Farm with Artificial Intelligence Technique https://mjst.ustp.edu.ph/index.php/mjst/article/view/1342 <p><em>Owing to the escalating environmental and social problems linked to climate change and the hastily depleting stock of hydrocarbon-based fuels, renewable power generation modes have attained massive prominence. Wind power is an important renewable energy generation technology that contributed to 5% of the planet’s power generation in 2020. However, for sustaining the Paris Agreement targets, the global wind power generation sector necessitates evolving at a fleeter pace. To expand the green switch of the worldwide power generation businesses, wind farms are expected to remain financially more advantageous than fossil fuel-based power plants. The present work focused on elevating the annual profit of wind farms by employing an amended genetic algorithm (GA). A fresh approach to dynamically apportioning the crossover and mutation prospects for a GA-enabled profit growth algorithm was suggested to amplify the capability of the GA. Three dissimilar terrain conditions with diverse obstruction configurations and a randomly generated non-uniform wind flow pattern were used for assessing the competence of the proposed algorithm for profit maximization. The results showed that the annual yields for Terrain Layouts 1, 2 and 3 obtained by the amended GA were higher by 10.34, 5.09 and 0.51%, respectively, than the typical one, which substantiated the superior proficiency of the former.</em></p> Prasun Bhattacharjee, Rabin K. Jana, Somenath Bhattacharya ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1342 Thu, 22 Dec 2022 07:22:56 +0000 Very Low Seroprevalence of Porcine Reproductive and Respiratory Syndrome among Backyard Pigs in Leyte Province and Factors associated with S/P Ratios https://mjst.ustp.edu.ph/index.php/mjst/article/view/1339 <p><em>Porcine Reproductive and Respiratory Syndrome (PRRS) is a viral disease that causes significant production and economic losses to swine raisers. To estimate the</em><br><em>seroprevalence of PRRS in pigs from the backyard and small-hold farms in the province of Leyte, Philippines, a total of 384 pigs were sampled at random from 11</em><br><em>localities and their sera were tested for PRRS antibody using indirect enzyme-linked immunoassay. Univariable and multivariable regression analyses were performed to determine the factors associated with the S/P ratios. Results revealed that the true seroprevalence for PRRS in backyard pigs was 0.28% (0.0001 to 0.0155, 95% CI) and the true herd-level seroprevalence was 1.02% (0.0005 to 0.1588, 95% CI). Factors significantly associated with the S/P ratios were: Large White (breed) (adjusted β = 0.22, p = 0.0014), the presence of goats (adjusted β = -0.63, p &lt; 0.0001) in farm vicinity, disposing wastes to bodies of water (adjusted β = 0.27, p &lt; 0.0001) and separating sick animals (adjusted β = 0.34, p &lt; 0.0001). The very low seroprevalence in the backyard and small-hold pig farms may indicate a low prevalence of PRRS in the province. Practices in backyard farms like disposing of pig wastes to water bodies and separating or moving sick animals were present and may promote the spread of the virus and pose higher risks when future disease outbreaks occur. It is recommended that the government impose proper waste management on backyard swine farms to prevent the spread of PRRS and other economically important swine diseases.</em></p> Kenny Oriel A. Olana, Loinda R. Baldrias ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1339 Thu, 22 Dec 2022 06:58:30 +0000 Growth and Yield of Screenhouse-grown potted Pechay (Brassica rapa L. ssp. chinensis cv. Black Behi) in selected Davao-produced Composts https://mjst.ustp.edu.ph/index.php/mjst/article/view/1340 <p><em>Pak choi (Brassica rapa subsp. chinensis), locally called pechay, is a nutritious and sought-after vegetable among Asian consumers as its edible petioles and green leaves are suitable in various recipes. The use of composts and organic amendments is integral to organic agriculture which is promoted in Davao City, Philippines. However, there are no published local studies in the city on the effect of recently formulated composts on crops. Thus, this study explored how these compost amendments affect the growth and yield of potted Black Behi pechay under screenhouse conditions using a completely randomized design. Results revealed that germination was higher in seeds sown in pure potting mix (90 to 94 %) and vermicompost-amended potting mixes (94 to 100 %) than with Dr. Bo’s Biofertilizer (DBB) (75 to 92%). Mean plant height (18.42 cm), leaf length (10.31 cm) and leaf width (5.89 cm) were highest in plants grown in potting mixes amended with 20% Tacunan vermicompost (Tacunan). Furthermore, there were pest and disease incidences in plants under all treatments but the least incidence was observed in plants grown in DBB. Total fresh weight (14.71 g), dry weight (0.76 g) and marketable fresh weight (12.19 g) obtained were exhibited by plants grown in 20% Tacunan. Total biomass, however, was highest in the urea-amended potting mix (15.42%). Results revealed that the application of composts positively influenced the growth and development of Black Behi pechay with 20% Tacunan as the recommended amendment. </em></p> Jose Romeo M. Lagon, Reynaldo G. Abad, Emma Ruth V. Bayogan, Cyrose Suzie C. Silvosa-Millado ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1340 Thu, 22 Dec 2022 06:59:42 +0000 Population Parameters of Asiatic Hard Clam, Meretrix meretrix (Bivalvia: Veneridae), in Panguil Bay, Philippines https://mjst.ustp.edu.ph/index.php/mjst/article/view/1341 <p><em>Asiatic hard clam (Meretrix meretrix) is abundant and artisanally harvested in Panguil&nbsp;</em><em>Bay, Philippines. Information about its current status through stock assessment is vital&nbsp;</em><em>to support management measures. In this study, estimation of the population&nbsp;</em><em>parameters of the clam was done using FiSAT II software from May 2018 to April&nbsp;</em><em>2019. A total of 2,760 clams were collected and analyzed. The length-weight&nbsp;</em><em>relationship showed negative allometric growth. The asymptotic length (L</em><sub><em>∞</em></sub><em>) and&nbsp;</em><em>growth coefficient (K) of the von Bertalanffy growth formula for M. meretrix were&nbsp;</em><em>estimated at 40.95 mm and 0.71 year</em><sup><em>-1</em></sup><em>, respectively. The estimated growth&nbsp;</em><em>performance index (φ’) was 3.07. The predicted maximum life span (t</em><sub><em>max</em></sub><em>) of the clam&nbsp;</em><em>was 6.47 years. Recruitment occurred throughout the year except for April and was&nbsp;</em><em>bimodal. Estimated total mortality (Z) was 3.18 year</em><sup><em>-1</em></sup><em>, fishing mortality (F) at 1.96&nbsp;</em><em>year</em><sup><em>-1</em></sup><em>, natural mortality (M) at 1.22 year</em><sup><em>-1</em></sup><em>, and exploitation level (E) was 0.62. High&nbsp;</em><em>recorded fishing and exploitation rate can indicate that the M. meretrix stock in&nbsp;</em><em>Panguil Bay experiences overexploitation that demands immediate sustainable&nbsp;</em><em>management.</em></p> Robert Keith A. Sienes, Mark Anthony O. Lucaser, Ephrime B. Metillo ##submission.copyrightStatement## https://mjst.ustp.edu.ph/index.php/mjst/article/view/1341 Thu, 22 Dec 2022 07:01:14 +0000