Monthly Archives: November 2019



About the Special Issue

Properties of soils in the marginal upland of Sta. Rita, Samar, Philippines

Kenneth Oraiz and Victor B. Asio

Evaluation of different cropping systems for marginal uplands in Barangay Caticugan, Sta. Rita, Samar

Ulysses A. Cagasan, Ed Allan L. Alcober, Mark Gil B. Gerona and Gretchen Mae M. Prado

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

Berta C. Ratilla, Loreme S. Cagande and Othello B. Capuno

Growth and yield of okra (Abelmoschus esculentus (L.) Moench) grown in the marginal upland area of Sta. Rita, Samar as influenced by different planting densities and mulching materials

Zenaida C. Gonzaga, Warren L. Obeda, Ana Linda G. Gorme, Jessie C. Rom, Oscar F. Abrantes Jr. and Othello B. Capuno

Postharvest handling intervention for banana var la tundan grown in marginal upland areas in Inopacan, Leyte

Marcelo A. Quevedo, Arsenio D. Ramos, Ness Marie Sta. Iglesia and Kris Benzon V. Notarte

Traditional knowledge and natural resources management for agricultural production in the marginal uplands: the case of Brgy. Caticugan, Sta. Rita, Samar

Jedess Miladel N. Salomon, Annabella B. Tulin, Marciana B. Galambao and Michelle E. Gumba

Design, fabrication, and comparative evaluation of plant power shredder

Feliciano G. Sinon, Alberto C. Martinez Jr and Ruth B. Abadiano

Fermented rice rinse field trial in backyard pig raising

Julius V. Abela, Eva C. Rom, Norberto E. Milla, Lolito C. Bestil, Othello B. Capuno and Victor B. Asio

Soil erosion in the marginal upland of Inopacan, Leyte

Faustino P. Villamayor, Victor B. Asio, Arjay O. Lerios, Luz G. Asio and Jessie R. Sabijon

Rainforestation farming to rehabilitate marginal uplands: history of its development

Victor B. Asio

Chemical quality of extracted oil and sensory quality of vacuum fried jackfruit (Artocarpus heterophyllus Lam.) pulp as influenced by frying cycle

Authors: Jason D. Braga1, Lorina A. Galvez2*, Roberta D. Lauzon3 and Yan Diczbalis4


Oil quality is important in the production of quality and safe fried food products. This study aimed to assess the quality of oil extracted from vacuum-fried jackfruit pulp products and the fried products at Visayas State University (VSU), Baybay City, Leyte, Philippines, with the coconut oil used until 20 frying cycles. The percent free fatty acid (FFA), acid value (AV) and peroxide value (PV) of the oil extracted from the product (1st, 5th, 10th, 15th & 20th frying cycle vacuum-fried jackfruit pulp) was determined employing titrimetric method. Quality descriptions and acceptability of the product were obtained through sensory evaluation, following standard protocols. Data were subjected to analysis of variance for significance and post hoc test to compare means. Results revealed that the increase of the frying cycle significantly (p≤0.05) increased the peroxide value, while no significant effect was noted with free fatty acid and acid values. Aroma, taste and general acceptability of the product were significantly affected by the increase in number of frying cycle of oil due to the quality changes of the oil being used. No significant effect was observed for color and texture acceptability with frying cycle. Generally, acceptability of the product decreased with increasing frying cycle. The oil can be recycled at least 10 frying cycles to produce quality and safe vacuum-fried jackfruit product for the consuming public. The reusing of oil provides cost effectiveness in the vacuum-fried jackfruit processing.

Keywords: jackfruit, oil quality, sensory evaluation, vacuum frying

Annals of Tropical Research 41(2):130-141(2019)
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Physical characteristics of soils in the landslide areas of Cadac-an Watershed in Leyte, Philippines

Authors: Jorge P. Cabelin1* and Beatriz C. Jadina2


Landslides have become very frequent in Leyte which justifies the need for soil assessment and characterization of the landslide-prone areas in the province. This study assessed the physical characteristics of soils from the landslide areas in Cadac-an watershed in Leyte, Philippines. Landslide cuts located in the central highlands of Cadac-an watershed were used as representative profiles in this study. These were examined, characterized and sampled for the analyses of soil physical properties which include particle size distribution (Pipette method), bulk density (Paraffin-clod method), particle density (Pycnometer method), porosity, total soil wet density, water holding capacity and field capacity (Gravimetric method), saturated hydraulic conductivity (Constant head method), liquid limit and plastic index. Generally, soils from the landslide areas in Cadac-an watershed had a sandy loam to clay loam to clayey texture, low bulk density, low particle density, high porosity, moderate total soil wet density, moderate to high water holding capacity, low to moderate field capacity, moderately high to high saturated hydraulic conductivity, moderate liquid limit and low plastic index. Based on the above characteristics, the soils are susceptible to landslide occurrence thus it is highly recommended to conduct constant assessment and monitoring the area.

Keywords: landslides, soil physical characteristics, watershed, Leyte, Philippines

Annals of Tropical Research 41(2):115-129(2019)
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Split crown technique for mass propagation of pineapple (Ananas comosus L.) var. queen

Authors: Sarah M. Ravelo* and Arsenio D. Ramos


The major problem limiting large scale commercial production and/or expansion of pineapple production is the difficulty in obtaining large quantity of quality planting materials due to slow rate of multiplication by conventional methods of propagation that mostly relies on the use of suckers and slips.
The study investigated the effect of the methods of crown preparation on the sucker production of pineapple var. Queen and to evaluate the horticultural qualities of suckers produced from plantlets prepared using different methods of crown preparation.
Destroying the growing point without splitting reduced percentage survival of plantlets but destroying the meristem and splitting the crown into two or four sections improved survival comparable to the intact crown. Destruction of the growing point and then splitting the crown promoted emergence and increased the number of suckers relative to the intact crown which did not produce suckers after, 3 months from planting. Increasing the number of sections prepared per crown (from two to four) did not reduce the number of suckers produced per plantlet and thus increased the multiplication rate by 7 and 8 times, respectively.
The method of crown preparation did not significantly influence the early growth performance (survival, height, number size of leaves) of the harvested & suckers during the first 6 months potting. Among the three methods of crown after preparation, destroying the meristem and splitting into two or four produced more number of ready-to-plant Queen pineapple suckers (1-ft tall) within a period of 5 months.

Keywords: Ananas comosus, crown preparation, sucker production, sucker quality

Annals of Tropical Research 41(2):100-114(2019)
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Morphological and physiological performance of PSB Rc18 lowland rice (Oryza sativa L.) grown at different water, spacing and nutrient management

Authors: Ruth O. Escasinas1* and Oscar B. Zamora2


Rice yield fluctuates because of environmental influences on morphological and physiological processes, as well as inadequate human intervention, to stabilize crop productivity. A field experiment was conducted in two cropping seasons at the experimental area of the Department of Agronomy, Visayas State University, Baybay, Leyte to evaluate the morphological and physiological performance of lowland rice grown at different water, spacing and nutrient management. Different sources of fertilizers were designated as the mainplot and plant spacing as the subplot nested within two water regimes, ie, continuous flooding and no flooding.
Lowland rice s under no flooding were shorter than those under plant continuous flooding. No flooding gave higher root pulling resistance, crop growth rate, net assimilation rate, leaf area index and harvest index and consequently produced higher grain yield of PSB Rc18. No flooding and continuous flooding water management resulted in the formation of aerenchyma cells in roots of rice plants which had statistically similar cell number and measurement. Wider spacing of 40cmx40cm gave the highest RPR. Water, spacing and nutrient management did not influence the phyllochron and total number of leaves on the main culm of PSB Rc18. However, PSB Rc18 at early growth stages tended to have longer phyllochron because of transplanting shock.
No flooding, application of composted goat manure and closer spacing of 20cmx20cm is the best treatment combination that g ve similar yield to rice plants a applied with inorganic fertilizer at the rate of 90-30-30kg ha-1 N, P2O5, K2O.

Keywords: crop growth rate, harvest index, leaf area index, net assimilation rate, phyllochron, aerenchyma cells

Annals of Tropical Research 41(2):76-99(2019)
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Species diversity and composition of mangroves in Tacloban City, Philippines

Authors: Teofanes A. Patindol1* and Eulito V. Casas, Jr.2


This study reflects the present status of Tacloban City mangrove vegetation and would be useful for mangrove restoration program. Surveys of mangrove forests in Tacloban City were conducted from October to November 2017 in 12 selected sites. Quadrat method was used to assess the species composition and stand structure of the canopy layer, representing seaward, middle and landward zones. The mangrove forests in Tacloban City contain 23 mangrove species belonging to 12 families and 15 genera. Rhizophoraceae and Acanthaceae are the most dominating families. As per IUCN report, among the 23 species, 4 were recognized as threatened. These include the Endangered Camptostemon philippinensis, the Vulnerable Avicennia rumpiana and the Near Threatened Aegiceras floridum and Ceriops decandra. Rhizophora Apiculata is the most abundant species, followed by Sonneratia alba. Other abundant species are Avicennia officinalis, Avicennia marina and Rhizophora mucronata. The least abundant are Bruguiera gymnorrhiza, Camptostemon philippinensis and Xylocarpus granatum. The canopy layer is composed of small-sized trees with an average tree density of 1,678 per ha and stem density of 3,133 per ha. The average height and diameter are 6.15m and 8.95cm, respectively. Mangrove diversity is generally low. Shannon index of diversity value ranges from 0.762 to 1.132, with an average value of 0.914. Understory is characterized by few species of regenerants, low density and low species diversity.

Keywords: mangroves, composition, species diversity, Tacloban City, Philippines

Annals of Tropical Research 41(2):67-75(2019)
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Isolation and identification of microorganisms for polyurethane degradation

Authors: Julie D. Tan1* and Takuji Ohwada2


Plastic wastes decomposition has been a pressing environmental problem worldwide. In this study, polyurethane (PUR), a thermoset plastic was tested for biodegradation by polyurethane-degrading microorganisms that were isolated from a dumpsite at Kamishihoro, Tokachi, Obihiro, Japan. Actinomycetes were the most abundant microorganisms from soil samples. From the 65 isolated microbial species, 16 possessed polyurethane-degrading ability. These isolates exhibited clearing zones on Yeast-extract salts + Agar and gelatin with polyurethane (YES-AG + PUR). The PUR-degrading isolates were characterized and identified based on their DNA sequence patterns. Some isolates belong to the same genus or species. They were Bacillus chitinolyticus (B03, B04, B07), Streptomyces spp. (B13, B19, C13a, C15, C17a, C17b), Pseudomonas sp. (B20), Bacillus pumilus(B21), Streptomyces cuspidosporus (C10b, C18, C19) and Pseudallesscheria baydii (F04, F07). Streptomyces sp. coded as C13a, with base sequence homology of 99.7% with Streptomyces albogriseolus, was believed to produce the highest amount of both exo- and endo polyurethanases. This was demonstrated by the widest clearing zones when broth and cell-bound supernatants were inoculated into the YES-AG + PUR plate.

Keywords: Thermoset plastic, Actinomycetes, Coomassie Blue, Biodegradation

Annals of Tropical Research 41(2):57-66(2019)
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Prevalence and risk factors associated with Fasciola gigantica and Paramphistomum cervi infection through actual retrieval in Philippine Carabaos in Ormoc City Abattoir, Philippines

Authors: John Philip Lou M. Lumain1* and Lotis M. Balala2


This study determine the prevalence and risk factors associated with Fasciola and Paramphistomum and the co-infection of both parasites in 246 Philippine carabaos slaughtered in Ormoc City abattoir.Upon postmortem examination, adult parasites were collected from the organ of localization and identified based on morphological characteristics. Intrinsic factors [sex, age, weight, Body Condition Score (BCS)] and origin of the carabaos were recorded. The parasites identified were Fasciola gigantica and Paramphistomum cervi. The study showed a prevalence of 50.81% for F. gigantica, 4.31% for P. cervi and 32.11% for coinfection. was more prevalent in female carabaos (57.80%), carabaos more than three years of age (58.41%), >325kg bodyweight (60.36%) and higher than three body condition score (59.09%). Paramphistomum was common in female carabaos (51.37%), carabaos less than or equal to three years of age (46.82%), ≤325kg bodyweight (52.59%) and less than or equal to three (≤3) body condition score (49.64%). Carabaos originating from Leyte have a higher infection rate to Fasciola (53.30%) and Paramphistomum (46.70%) compared to carabaos , supplied by other provinces. Logistic regression modeling indicates that male carabaos are a protective factor (OR 0.59) against Paramphistomum infection while carabaos within Leyte have a greater likelihood of being infected with both parasites (OR 4.27 to 4.57). Pearson’s Correlation Coefficient (r-value) showed a strong and positive result (r=0.997**) that the likelihood of Fasciola and Paramphistomum co-exist (co-infection) together is high. A high prevalence rate of fluke infection has been recorded in carabaos admitted for slaughter implying, that most of the backyard carabao raisers are not practicing sound deworming, pasture and grazing management and proper deworming protocol. To prevent and control flukes and improve production and health of carabaos, the above-mentioned factors must first be considered.

Keywords: Fasciola gigantica, Paramphistomum cervi. Prevalence, Risk Factors, co-infection, Philippine carabao

Annals of Tropical Research 41(2):43-56(2019)
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Fate of phosphorus fertilizer in acidic Cambisol assessed using 33P isotope labeling technique

Authors: Deejay Maranguit1*,2 and Yakov Kuzyakov2,3


Direct 33P labeling approach is a very powerful technique that has high sensitivity in tracing the fate of added phosphorus (P) fertilizers across various P pools. Nonetheless, only a few studies have used this approach. This study traced the fate of applied P fertilizer in acidic P-limited soil using the 33P labeling approach.The incorporation of 33P-labeled KH2PO4 in available P (PAEM), microbial biomass P (Pmic) and Fe/Al-bound P (PNaOH) pools was followed in Cambisol as influenced by C and N sources applied as glucose and ammonium sulfate, respectively.Results showed that not all of the added P fertilizer remains in available pool; instead, it was distributed to poorly-available pools. Fast, almost instantaneous P fixation by the Fe and Al oxides and immobilization by microbial uptake were recorded.Applying glucose boosts microbial growth and demand for P, resulting in increased 33P recovery. High 33P recovery in Pmic (20% of the applied 33P) and in PNaOH (45% of applied 33P) showed the dominance of P immobilization by microorganisms and adsorption by Fe and Al oxides on the fate of P in an acidic soil. Nevertheless, these can contribute to long-term P availability after the turnover of microbial biomass and desorption of fixed P.

Keywords: 33P isotopic labeling; Phosphorus dynamics; Phosphorus availability; Phosphorus fractions; Microbial biomass P; P-limited soil

Annals of Tropical Research 41(2):32-42(2019)
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In vitro growth response to bacterial wilt pathogen of banana (var. lakatan, Musa acuminata Colla) plantlets regenerated from ethyl methanesulfonate-treated shoot explants

Authors: Nonna Fatima H. Abello1and Tessie C. Nuñez1*


Bacterial wilt caused by Ralstonia solanacearum leads to death of infected suckers and reduces the yield of commercially important banana varieties like Lakatan. Among the many varieties of banana, no germplasm with bacterial wilt resistance has been identified yet (Tripathi et al 2004).
Mutation induction in plants to develop disease resistance genes using physical or chemical mutagens has been used as alternative to harmful pesticides. To induce mutation for the possible development of resistance to bacterial wilt, shoot tips of Stage 2 in vitro-grown Lakatan plantlets were exposed to 0.1% and 0.2% ethyl methanesulfonate (EMS) for 12 and 24h. Treated and untreated explants were cultured in-vitro to regenerate plantlets.
Shoots emerged two days after in vitro inoculation of explants treated with – 0.1% EMS for 12h. Significantly longer shoots also developed from the cultures compared to the untreated explants. The other explants exposed to other treatments had shoot emergence one to three days later. Falcate, curled, irregularly-shaped, and yellowish leaves and pseudostems also developed in EMS-treated cultures.
Untreated plantlets exhibited at least one bacterial wilt symptom such as leaf spots, necrosis at pseudostem base, and death six days from the introduction of Ralstonia solanacearum in vitro. Plantlets from explants exposed to 0.1% EMS for 12h did not exhibit disease symptoms even after ten days of exposure to the pathogen and had 100% survival. Seventy one percent of plantlets from explants exposed to 0.1% EMS for 24h and 55% from explants treated with 0.2% EMS for 24h also survived without infection. The surviving plantlets need to be studied further for their ex vitro responses to the pathogen and determine possible genetic changes due to the chemical mutagen treatment.

Keywords: in vitro growth of banana, Ethyl methanesulfonate, Bacterial wilt screening, Ralstonia solanacearum

Annals of Tropical Research 41(2):18-31(2019)
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