Category Archives: Volume 44 No. 1 (2022)

Surfacing development needs of a marginal upland community through participatory tools: The case of village in Samar, Philippines

Authors: Editha G. Cagasan1*, Rotacio S. Gravoso1, Milagros C. Bales1, Ernesto F. Bulayog1, Elvira E. Ongy1 and Flordelaine T. Alao2


Efforts to alleviate the productivity of marginal uplands necessitate the use of participatory approaches to identify development needs of the community. However, despite the popularity of participatory methods for assessing community resources and needs, the literature lacks information on how it works, especially in the Philippine setting. This study aimed to determine the needs of a marginal upland community and demonstrate the use of the participatory tools. Data were gathered in a marginal upland community in Samar, Philippines whose primary source of livelihood of the residents is farming. Rice is the staple food. The people’s livelihood activities are beset by some threats, including scarcity of water in the area, declining soil fertility of their farms, extreme weather events, and the occurrence of pests and diseases. To augment their livelihood, the people identified livelihood projects, including food processing, vegetable farming, and animal raising. However, results of the resources vulnerability analysis indicate that the assistance needed by the community should go beyond training workshops on crop production, food processing, and animal raising. The assistance should also consider the rehabilitation of the environment, which is now highly degraded. The implementation of a Rainforestation project may be considered to raise food crops and rehabilitate the watershed of the community to address its serious problem of water scarcity. There may also be a need to identify other crops that would survive in the area given its current condition so that the people will have food sources aside from rice. This study has demonstrated that use of participatory tools allows for the collection of in-depth information on community needs and promotes active participation among the participants.

Keywords: community needs, livelihood projects, upland farmers, Samar

Annals of Tropical Research 44(1):99-113(2022)
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The effects of different tillage practices on soil properties, yield and pest incidence of various Sweet Corn (Zea Mays L. Var. Saccharata) varieties

Authors: Angela R. Escototo1 and Ulysses A. Cagasan1*


Conservation tillage is one of the crop production adaptation strategies for conserving soil and mitigating climate change. This study aimed to evaluate the effects of different tillage practices on the yield, soil properties, and pest incidence of corn varieties that would give optimum output. The experiment was laid out in a split-plot arranged in a randomized complete block design with three replications. Zero and minimum tillage served as the main plot, and the different sweet corn varieties as the subplot (T1– Macho F1, T2– Sweet Supreme F1, T3– Purple Magic F1, T4– Hi-Brix XL F1, and T5– Sugar King F1). Results showed that Hi-Brix XL F1 (8t ha-1), Purple Magic F1 (7.44t ha-1), and Macho F1 (7.45t ha-1) obtained high marketable ear yields among the different sweet corn varieties. On the other hand, zero and minimum tillage did not vary significantly in terms of the soil properties, resulting in no yield advantage for sweet corn. This means that sweet corn production can be done either with zero or minimum tillage. In addition, zero tillage practice obtained lower fresh weight (g) of weeds at 15 and 45 days after planting. Weeds were eliminated using non-selective herbicide spray with zero tillage, resulting in lower weed incidence than with minimum tillage where only one plowing and harrowing were done.

Keywords: Conservation tillage, sweet corn varieties, and yield performance

Annals of Tropical Research 44(1):86-98(2022)
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Candida albicans in backyard chicken flocks raised in a small community in Leyte, Philippines: Prevalence and risk factors associated

Authors: Kenny Oriel A. Olana*, Ana Marquiza M. Quilicotand Eugene B. Lañada


This study aimed to determine the prevalence of Candida albicans in backyard chickens flocks among small hold raisers in selected villages of Baybay City, Leyte and to identify the risks factors associated with the prevalence of C. albicans. Using Sabouraud’s dextrose agar, 185 (68.5%) out of 270 samples were positive with yeast and 94 (34.81%) out of those yeast isolates were positive for C. albicans. Multivariable logistic regression analysis results show unconditional association between the sex of the chicken with the isolation of C. albicans. The odds of roosters harboring C. albicans is 56% lower than hens (OR=0.44, 95% CI 0.2-0.7) with a p-value of 0.0047. Considering the possibility of contact between smallholder chicken flocks and the community, the isolation of C. albicans from apparently healthy chickens necessitates the implementation of proper hygiene and sanitation management especially in small-hold chicken flocks.

Keywords: candidiasis, fungal zoonosis, chicken, poultry candidiasis

Efficacy of Trichoderma harzianum against Fusarium oxysporum and Rhizoctonia solani on bean and tomato plants

Authors: Gwendolyn Ban1*, Shamsul Akanda2 and Macquin Maino3


Experiments were conducted in the laboratory, greenhouse, and field at the Papua New Guinea University of Technology (PNGUT) to assess the efficacy of Trichoderma harzianum against Rhizoctonia solani and Fusarium oxysporum. The dual culture of T. harzianum with R. solani and F. oxysporum isolated from the diseased bean and tomato plants under laboratory conditions showed 60.1% and 63.3%, and 54.9% and 61.6% growth reduction for R. solani and F. oxysporum, respectively. In greenhouse fungal inoculation experiments, bean and tomato plants showed relative germination index ranging from 0.56 to 1, 0.83 to 1, and disease reduction ranging from 64.8 to 96.1, and 20.3 to 83.7%, respectively. Field experiments involved tests with T. harzianum against one pathogenic fungus or against a combination of both R. solani and F. oxysporum,, applied simultaneously as the pathogenic fungi or five days before application of pathogenic fungi. The results for bean and tomato plants showed relative germination index ranging from 0.42 to 0.94, and 0.63 to 0.94, and disease reduction recorded at 63.8 to 96.1%, and 11.3 to 63.9%, respectively. The outcomes of this study will form the basis for further investigation into the potential routine use of Trichoderma spp. as biological control agents against soil-borne pathogens in PNG.

Keywords: Trichoderma, R. solani, F. oxysporum, biological control

Annals of Tropical Research 44(1):30-45(2022)
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Influence of potassium fertilization on the functional components and antioxidant activity of pummelo [Citrus maxima (Burm. Ex Rumph.) Merr.] fruit

Authors: Alminda Magbalot-Fernandez1*and Constancio C. De Guzman2


This study aimed to determine the influence of potassium (K) fertilization on the functional components and antioxidant activity of 13-year-old ‘Magallanes’ pummelo [Citrus maxima (Burm. Ex Rumph.) Merr.]. The field experiment was conducted at South Davao Corporation (SODACO) farm, Davao City for 12-month duration. Five treatments with increasing K levels were applied per tree: control, no K, 150g K basal, 225g K basal, and 225g K basal + foliar application. The functional components and antioxidant activity were analyzed following harvest at the University of the Philippines, Los Baños.

Application of 225g K rates positively influenced functional components of pummelo. The yield of total phenol, flavonoid, vitamin C and oil per tree increased by 3-10 times with 225g K application.

The effects of basal alone and foliar + basal application of K were only significantly different from each other in terms of flavonoid yield per tree. On the other hand, the application of 225g K basal + foliar resulted to higher total phenol, vitamin C and oil yield per tree in pummelo, implying a higher mobilization of K in the leaves than K uptake by the roots. The results of the study indicated the important role of K in improving the functional components in ‘Magallanes’ pummelo.

Keywords: Functional Components, Antioxidant Activity, Pummelo, Potassium

Annals of Tropical Research 44(1):17-29(2022)
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Insect vectors transmitting Phytoplasma to vegetables in Eastern Visayas Philippines

Authors: Lucia M. Borines1*, Nickie D. Duero1, Joy Adeline C. Nuñez1, Rezel Sagarino-Borines2, Reny G. Gerona1 and Sandra McDougall3


Phytoplasma diseases are found affecting vegetables in Eastern Visayas, Philippines. Identifying the insect vectors that transmit phytoplasma in the field is necessary for the management of this disease. This study was conducted to identify the vectors of phytoplasma affecting bitter gourd, loofah, and string beans. Insects associated with these vegetables that had shown phytoplasma symptoms in the field were collected, mass-reared, and the progenies of mass reared insects were used for transmission to healthy host plants. Phytoplasma detection was done through PCR and nest PCR assays. Phytoplasma was positively transmitted to healthy bitter gourd plants by a cicadellid leafhopper, Hishimonus sp. and brown planthopper, Ricania speculum. The ~ 1.25Kb phytoplasma-specific band was amplified in these insects. The phytoplasmas transmitted by the Hishimonus sp. and R. speculum produced two different types of symptoms to the bitter gourd, and rDNA sequence analysis separated them into two clusters which confirmed that the phytoplasmas belong to two different strains. Although the Aphis gossypii and Aphis craccivora also produced symptoms in bitter gourd and string beans, and the pathogen was detected in the insects, whether they vectored phytoplasma to their respective hosts needs further study, since the symptoms produced were quite different from the ones produced by the cicadellid leafhopper and Ricania speculum.

Keywords: Hishimonus sp., Ricania speculum, bitter gourd, witches broom

Annals of Tropical Research 44(1):46-60(2022)
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Conventional biotyping revealed Mycoplasma and antimicrobial resistant Escherichia coli and Salmonella isolates during disease outbreak in broiler farms and hatcheries in Leyte, Philippines

Authors: Eugene B. Lañada1*, Harvie P. Portugaliza1, Analyn I. Blanza2, Mercy Cheryll C. Espejo3 and Ma. Delia A. Pagente1


A respiratory disease outbreak investigation was carried out from October to December 2015 in three broiler farms and two hatcheries in Leyte. Three- to seven-day-old chicks from farms were initially brought to CVM diagnostic laboratory for necropsy and microbial analyses. Subsequent visits to hatcheries and farms were made for random swabbing and sampling of physical facilities, equipment, vehicle, unhatched eggs, 18-day old eggs, eggshells, and day-old chicks. Chick necropsy, embryo examination, and bacteriological method for Mycoplasma, Escherichia coli, Salmonella, and Aspergillus were performed. Antimicrobial sensitivity testing was conducted for Salmonella and E. coli isolates. The main clinical sign observed in chicks was dyspnea. Necropsy revealed consistent bilateral fibrinous airsacculitis and perihepatitis with few cases of pericarditis, wherein sampled organs consistently showed the presence of E. coli. Out of 83 samples collected, 19 (22.89%) Salmonella, 40 (48.19%) E. coli, and no Aspergillus were isolated. Most E. coli were isolated from chick embryos and necropsied chickens, while Salmonella isolates were mostly from the environment. Mycoplasma was isolated from 63.64% (7/11) of sampled lungs, air sacs, and liver from unhatched embryos (100%), 18-day old embryos (50%), and day-old chicks (33.33%). The majority of Salmonella and E. coli isolates showed multidrug resistance against amoxicillin, chloramphenicol, erythromycin, trimethoprim/sulfamethoxazole (TMPS), and tetracycline. Few isolates were sensitive to ciprofloxacin. Our results should raise awareness on the occurrence of antimicrobial-resistant E. coli and Salmonella, and coinfection with Mycoplasma among broilers in Leyte. Therefore, proper selection and usage of antibiotics should be advocated in all poultry farms.

Keywords: Antimicrobial-resistant, E. coli, Mycoplasma, Poultry outbreak, Salmonella

Annals of Tropical Research 44(1):74-85(2022)
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PCR optimization for the detection of bunchy top virus of abaca (Musa textilis Nee) in Eastern Visayas Philippines

Authors: Jofil A. Mati-om*, Meriam B. Mati-om and Robelyn T. Piamonte


The bunchy top virus in Eastern Visayas has serverly reduced abaca production. Early and accurate detection of plant viral pathogens is an essential and crucial component for disease management. At present, there are no standard PCR conditions in the Eastern Visayas region for detecting the bunchy top virus at an early stage using PCR. Thus, optimization for the detection was carried out to assist in disease management. Different annealing temperatures (57, 60 and 65oC), gel concentrations (1, 1.5 and 2%), and running conditions (80, 90 and 100 volts) were tested using My TaqTM DNA Polymerase (Bioline, USA). The annealing temperatures of 57oC and 60oC resulted in DNA amplification as indicated by the presence of bands but absence of bands at 65oC. The higher voltages of 90 and 100 volts resulted in smears and distorted DNA bands with 1% and 1.5% agarose; thus 2% agarose gel was used to resolve small DNA fragments (100bp to 3kb). Electrophoresis using 80 volts for 45min successfully separated the DNA bands. The amplification of the product with internal control primers indicated the absence of PCR inhibitors in the abaca-extracted DNA samples. This confirmed the negative PCR reaction as indicative of the absence of the virus. The optimized PCR conditions could be applied by students and researchers for the early detection of bunchy top virus in the National Abaca Research Center Germplasm collection and the region.

Keywords: bunchy top virus, PCR, Manila hemp, detection, abaca hybrid

Annals of Tropical Research 44(1):61-73(2022)
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Assessment of sesquioxides status of some uplands soils in humid southwest Nigeria

Authors: Julius Olayinka Ojetade1*, Ruth Oluwakemi Adegbenro1, Emmanuel Adeboye Adesemuyi2, Sikiru Adekoya Muda1 and Alani Adeagbo Amusan1


Assessment of some sesquioxides in the upland soils in southwestern Nigeria was undertaken to evaluate their degree of weathering under humid tropical conditions. Samples were taken from genetic horizons of eight soil profile pits sited at different physiographic positions along two toposequences in southwestern Nigeria. The samples were analyzed for gravel content, particle size distribution, bulk density, pH, organic carbon, total nitrogen, available P, exchangeable bases, crystalline and amorphous forms of Fe and Al, using standard procedures. Sand fraction ranged from 31–76% (54.49±11.34), silt from 3–19% (10.21±3.61) and clay from 10–55% (35.3±9.7). Bulk density increased with profile depth, ranging between 1.12 and 1.64g cm-3 (1.39±0.13). The pH was low (4.2–6.1; 5.0±0.55), organic carbon content ranged from 0.75–15.99g kg-1 (5.79±3.49) with higher values in the surface horizons. Total nitrogen content ranged from low to medium (0.13–2.75g kg-1; 1.16±0.49) while available phosphorus ranged from 0.49–11.63mg kg-1 (4.30±3.57) across the horizons. Crystalline forms of Fe (Fed) and Al (Ald) ranged from 10.26–39.82g kg-1 and 0.41–1.80g kg-1, respectively while the amorphous forms (Feo and Alo) ranged from 0.41–2.60g kg-1 and 0.83–1.64g kg-1, respectively. The crystalline forms of Fed and Ald were more dominant over the amorphous forms of Feo and Alo. The argillic (Bt) horizons of pedons had significant accumulation of clay particles and free iron. The weathering indices of clay and free iron accumulation in argillic (Bt) horizons of the pedons indicated that the soils of the study area were well-drained, deeply weathered and intensely leached with few weatherable minerals available for plant uptake.

Keywords: Sesquioxides, Upland Soils, Nigeria

Annals of Tropical Research 44(1):1-16(2022)
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Volume 44 No. 1 JANUARY – JUNE 2022


Assessment of sesquioxides status of some upland soils in humid southwest Nigeria

Julius Olayinka Ojetade, Ruth Oluwakemi Adegbenro, Emmanuel Adeboye Adesemuyi, Sikiru Adekoya Muda and Alani Adeagbo Amusan

Influence of potassium fertilization on the functional components and antioxidant activity of pummelo [Citrus maxima (Burm. Ex Rumph.) Merr.] fruit

Alminda Magbalot-Fernandez and Constancio C. De Guzman

Efficacy of Trichoderma harzianum against Fusarium oxysporum and Rhizoctonia solani on bean and tomato plants

Gwendolyn Ban, Shamsul Akanda and Macquin Maino

Insect vectors transmitting phytoplasma to vegetables in Eastern Visayas Philippines

Lucia M. Borines, Nickie D. Duero, Joy Adeline C. Nuñez, Rezel Sagarino-Borines, Reny G. Gerona and Sandra McDougall

PCR Optimization for the detection of bunchy top virus of abaca (Musa texilis Nee) in Eastern Visayas Philippines

Jofil A. Mati-om, Meriam B. Mati-om and Robelyn T. Piamonte

Conventional biotyping revealed Mycoplasma and antimicrobial resistant Escherichia coli and Salmonella isolates during disease outbreak in broiler farms and hatcheries in Leyte, Philippines

Eugene B. Lañada, Harvie P. Portugaliza, Analyn I. Blanza, Mercy Cheryll C. Espejo and Ma. Delia A. Pagente

The effects of different tillage practices on soil properties, yield and pest incidence of various sweet corn (Zea Mays L. Var. Saccharata) varieties

Angela R. Escototo and Ulysses A. Cagasan

Surfacing development needs of a marginal upland community through participatory tools: The case of a village in Samar, Philippines

Editha G. Cagasan, Rotacio S. Gravoso, Milagros C. Bales, Ernesto F. Bulayog, Elvira E. Ongy and Flordelaine T. Alao

Candida albicans in backyard chicken flocks raised in a small community in Leyte, Philippines: Prevalence and risk factors associated

Kenny Oriel A. Olana, Ana Marquiza M. Quilicot and Eugene B. Lañada