Category Archives: Volume 44 No. 2 (2022)

Growth and yield response of lowland rice (Oryza sativa L.) to planting density and nutrient management

Authors: Geleca C. Igdanes-Marañan1* and Berta C. Ratilla2


Planting density and nutrient management practices may affect lowland rice production. This study was conducted to evaluate their effects on growth and yield of lowland rice (NSIC Rc400), determine the appropriate number of seedlings hill-1 and nutrient management for optimum yield, and assess their profitability on rice. A split-plot arranged in Randomized Complete Block Design was used with three replications. Planting densities (M1=1 seedling hill-1 and M2=3-5 seedlings hill-1) were designated as mainplots while nutrient management practices as subplots;T1=0-0-0 (Control), T2=120–60–60kg ha-1 N, P2O5, and K2O, T3=60–30–30kg ha-1 N, P2O5, and K2O + 2.5t ha-1 vermicast + biweekly foliar urea spray, T4=45–30–30kg ha-1 N, P2O5, and K2O + 2.5t ha-1 vermicast + weekly foliar urea spray, and T5=30–30–30kg ha-1 N, P2O5, and K2O + 2.5t ha-1 vermicast + weekly foliar urea spray. Results revealed that M1 produced more filled spikelets panicle-1 regardless of nutrient management. Early heading and maturity were noted at T1, T4, and T5 treatments. Integrated nutrient application at T3 significantly increased growth, and yield parameters of lowland rice with higher gross income and benefit-cost ratio, next to the recommended dose of inorganic fertilizer (T2). This was due to the high labor and material cost incurred with the integrated nutrient application. Highest net income and benefit-cost ratio were obtained with M1 and T2. Transplanting 1 seedling hill-1 with combined inorganic and vermicast application (T3) seemed appropriate for NSIC Rc400 especially if the farmer has his own vermicast production.

Keywords: Foliar urea, integrated nutrient management, lowland rice, N use efficiency, vermicast

Annals of Tropical Research 44(2):163-181(2022)
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Growth, yield and microbial contamination of lettuce (Lactuca sativa L.) grown under two types of cultivation system as influenced by different organic fertilizers

Authors: Blanche Franchette D. Llera1*, Zenaida C. Gonzaga2 and Julie D. Tan1


Increasing popularity of lettuce in the tropics is becoming evident due to its widespread use in health and nutrition. Lettuce, a ready-to-eat vegetable is expected to be safe and of good quality. A study was conducted to assess the effect of different organic fertilizers on the growth, yield and microbial contamination of lettuce grown under two types of cultivation system. This was carried out in a combined analysis arranged in randomized complete block design with the following treatments: without organic fertilizer (control), cow manure, fresh chicken dung, dried chicken dung, vermicast and goat manure. Results showed that lettuce grown under structure performed better than in open field as manifested by early heading, bigger polar head size, longer and broader leaves and more compact head. Among the organic fertilizers used, dried chicken dung and vermicast enhanced the yield and yield components of lettuce. Microbial contaminants like E. coli were detected in soils applied with organic fertilizers. The highest microbial count was recorded in fresh chicken dung-treated soils in both open field and under structure. E. coli contamination in lettuce leaves was more evident in the open field than under structure. Regardless of soil and crop samples, treated or not, positive detection of Salmonella was observed.

Keywords: lettuce, protective structure, vermicast, dried chicken dung, E. coli, Salmonella

Annals of Tropical Research 44(2):150-162(2022)
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Social impacts of coconet enterprise on smallholder coconut farming family: The case of Panaon Island Farmers Federation Inc. in the Philippines

Authors: Henry Y. Goltiano2* and Feliciano G. Sinon1


This study looked into the social impacts of the cocotwine-coconet-making enterprise of the Panaon Island Farmers Federation, Inc. The study followed the constructivist research approach. Results showed that the enterprise had positive and negative impacts on PIFFI members, their families, PIFFI as an organization, their communities and their environment. Most impacts were positive, including acquisition of new knowledge and skills, improved economic productivity and income, changed values, built courage and confidence to take investment risk, molded financial discipline, strengthened family bond, reinforced community cohesion and improved the environment, among others. As a farmers’ organization, PIFFI demonstrated interest, capability and willingness to sacrifice to make its livelihood enterprise succeed. Smallholder coconut farmers organizations, like PIFFI, that demonstrate such characteristics deserve government assistance to enable them to optimize positive impacts of the livelihood enterprises that they are engaged in.

Keywords: social impact assessment, constructivist approach, conversational interview, family cohesion, rural out-migration, community cohesion

Annals of Tropical Research 44(2):119-149(2022)
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Prevalence and risk factors associated with equine strongylosis in Baybay City, Leyte, Philippines

Authors: Marjorie G. Amoto1 and Carl Leonard M. Pradera2*


Strongylosis is a pressing equine health problem. This study determined the prevalence and risk factors associated with strongylosis in horses in Baybay City, Leyte, based on its egg morphology. A total of 263 horse fecal samples were collected and examined. Nematode eggs were identified using Modified McMaster technique. Other relevant epidemiological data associated with strongyle infections were also collected using a structured questionnaire. Descriptive statistics and logistic regression analyses were carried out to determine the prevalence and risk factors associated with strongylosis in horses.
Results showed an overall prevalence of 97.72% (257/263; 95% CI=95.10-99.16); of which, 92.78% (244/263; 95% CI=91.18-94.37) were cyathostomins and 67.30% (177/263; 95% CI=64.41-70.19) were Strongylus sp. Logistic regression analyses revealed a significant association between Strongylus sp. infection and moderate body condition score (p-value=0.0006), housing in a shed (p-value=0.0255), and tethering of the horse (p-value=0.0116).
The high prevalence rate of equine strongyle infection in Baybay City, Leyte, could indicate the neglect and underestimation of the disease for a considerable period of time. Thus, active clinico-epidemiological investigations are warranted in order to design and establish cost-effective and sustainable control and preventive approaches.

Keywords: cyathostomin, epidemiology, horses, strongyle, Strongylus sp.

Annals of Tropical Research 44(2):104-118(2022)
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To eat or not to eat junk foods? Improvement in children’s intention to reduce junk foods consumption following exposure to a media literacy intervention

Authors: Nino Daryll Bicoy1and Rotacio S. Gravoso2*


Exposure to junk food information leads to high junk food consumption among children. This situation has raised concerns among agencies and organizations mandated to ensure children’s health because high junk foods consumption results in several health problems. This study aimed to ascertain the effects of a media literacy intervention on elementary school children’s knowledge, attitude towards junk foods, subjective norm, perceived behavioral control, and intention to eat junk foods and consume junk foods. Treatment groups included analysis+analysis, analysis+production, and no intervention. Children who underwent the analysis+production approach had significantly higher improvement in their attitude, subjective norm, perceived behavioral control, and intention during the post-test and the delayed post-test than those in the analysis+analysis approach and those not treated with any intervention. Results suggest that the analysis+production approach could improve children’s knowledge of junk foods’ health impacts and reduce their attitude towards eating junk foods, subjective norm, perceived behavioral control, and intention to eat junk foods. Overall findings indicate that initiatives aimed to encourage children to eat nutritious foods need repetition of the message. Aside from curriculum integration, engaging parents and application of game-based learning are also potential mechanisms for improving children’s food habits.

Keywords: anti-junk food initiatives, healthy food promotion, behavioral change, children’s food habits

Annals of Tropical Research 44(2):89-103(2022)
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Ethnomedicinal and biological activities of tropical mahua (Madhuca species) – A comprehensive review

Authors: Urmimala Das1, Ramesh C. Ray2 and Bishnupriya Hansdah1*


The genus Madhuca, of the family Sapotaceae is a multi-functional tropical tree with the species, Madhuca indica (latifolia), M. longifolia, and M. butyracea being the most prevalent. The nutritional and health benefits of mahua are due to the richness of its anti-oxidant, vitamin, mineral, and biochemical composition. Mahua plant (flowers, fruits, roots, bark, seeds, and leaves) extracts have a variety of bioactivities and ethnomedicinal applications (antidiabetic, anti-carcinogenic, anti-inflammatory, antimicrobial, etc.). They are traditionally well-known for their ability to prevent/treat various ailments. The phytochemical constituents have a defense mechanism and therapeutic role in the treatment of disease. Madhuca spp. has built the linkage between ethnic people, traditional knowledge, and livelihood support of the resources. This study/literature review has been undertaken to investigate the mahua as a forest resource that can be used for building livelihood resilience among ethnic communities. This review gives an extensive overview of the scientifically evaluated mahua plant extract bioactive molecules and a possible mechanism for the therapeutic potential for treating various diseases. Further, analyses of the opportunities and scope with future openings for the development of health-giving properties/abilities are extensively summarized.

Keywords: Madhuca, ethnobotany, bioactive agents, therapeutic activity, health benefits

Annals of Tropical Research 44(2):67-88(2022)
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Bacteriological examination of the water and sediments in Palhi and Salog rivers in Western Leyte, Philippines

Authors: Rufina Mae C. Lumagbas and Jayzon G. Bitacura*


Rivers around the world are threatened by destruction caused by anthropogenic activities despite the important services they provide for humanity. This study was conducted to determine the water classification and recommended beneficial uses of Palhi and Salog Rivers based on the most probable numbers of total coliforms, and also to evaluate the abundance of heterotrophic bacteria present in the water and sediments of the rivers as potential indicators of environmental disturbance. A Multiple-tube fermentation test was conducted to determine the most probable number of total coliforms in the river waters. Heterotrophic plate count of total aerobic heterotrophic bacteria was determined by counting the colony-forming units that grew on nutrient agar. Geometric most probable number means of total coliforms revealed that only the upstream of Palhi and Salog Rivers could be used for contact recreational activities. The midstream and downstream of both rivers are recommended for non-contact recreational activities only, due to elevated total coliforms. The heterotrophic plate count of total aerobic heterotrophic bacteria of water and sediment samples for the three stations in Palhi River were not significantly different while in Salog River higher numbers of total aerobic heterotrophic bacteria occurred in the downstream compared to the upstream. However, no significant differences on the heterotrophic plate count of total aerobic heterotrophic bacteria levels were found between the water and sediments for the two rivers. The results of this study imply that monitoring and proper management of the rivers should be done by all sectors of the community for the protection of these invaluable resources.

Keywords: Freshwater ecology, indicator bacteria, water quality monitoring, total coliforms, river system, heterotrophic plate count

Annals of Tropical Research 44(2):49-66(2022)
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Multivariate logistic regression analysis of risk factors for Salmonella spp. among ducks in selected barangays in Baybay City, Leyte

Authors: Neshelle D. Ceralvo1, Lotis M. Balala1*and Eugene B. Lañada1


Salmonella contamination in poultry and poultry products is a threat to public health and food safety. This study aimed to assess the carriage rate and the associated risk factors of Salmonella spp. among ducks in selected villages in Baybay City, Leyte, Philippines. Salmonella was identified using conventional culture methods. On-farm survey interviews were carried out with 400 duck farmers to generate information on the risk factors associated with Salmonella spp. Univariate analysis was performed to screen potential risk factors and multivariate logistic regression analysis to identify significant risk factors. The overall carriage rate of Salmonella in ducks was 22.75% ± 4.11. Multivariate logistic regression analysis identified the incorporation of snails into the diet (OR=5.212; 95% CI:1.374 to 19.765) and sources of water from rivers (OR=2.823; 95% CI:1.273 to 6.264) and ponds (OR=6.413; 95% CI:2.827 to 14.550) as significantly associated with Salmonella spp. in ducks in the sampled farms. The use of antibiotics (OR=0.022; 95% CI:0.003 to 0.196) and flooding in the rearing area (OR=0.485; 95% CI:0.242 to 0.971) indicated lower chances of Salmonella infection. The data suggested that Salmonella spp. does infect ducks in the target population. It is recommended that randomized field testing be carried out to validate these findings.

Keywords: carriage rate, demographics, farm management, odds ratio

Annals of Tropical Research 44(2):36-48(2022)
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Molecular and morpho-agronomic traits for vegetative stage drought tolerance in some rainfed elite rice lines

Authors: Minerva L. Gaurana-Nuñez1* and Pompe C. Sta. Cruz


Selection of drought-tolerant rice genotypes is still one of the most vital challenges in rice research and the use of molecular markers may offer a promising approach to fast track the selection and development of drought-tolerant rice. The aim of our study is to identify drought-tolerant traits, in selected rainfed elite rice lines, expressed during drought stress at the vegetative stages 20-32 DAS and 30-42 DAS. The study also validated the presence of SSR markers linked to drought tolerance. All morpho-agronomic traits examined in the study were significantly affected by drought, except for root length during 30-42 DAS of drought imposition. Drought significantly reduced the plant height, number of tillers, leaf area, and root number resulting in a significant reduction in root and shoot dry weight. On the other hand, an increase in total nodal root length was observed in all test genotypes except for AL-55, AL-97, and susceptible check PSB Rc82 under both drought conditions. All parameters examined in this study are useful traits for drought tolerance in rice, however responses might be genotype-dependent. The highest correlation was shown by root:shoot ratio (r=0.94, r=0.78) at 20 DAS and (r=0.89, r=0.67) at 30 DAS under well-watered and drought conditions, respectively. Seven amplified markers were present in the test genotypes except for RM 525, RM 60, RM 201, RM 1141. These four markers were absent in the drought-susceptible check PSB Rc82, hence, these markers may be used in selecting drought-tolerant genotypes through marker-assisted selection.

Keywords: Drought tolerance, Marker-assisted Selection, SSR markers, Rainfed lowland rice

Annals of Tropical Research 44(2):17-35(2022)
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Leaf-litter decomposition and nutrient release dynamics of some savanna agroforestry tree species: A model for soil improvement strategies

Authors: Oyebamiji Noah Alabi1*, Ibrahim Hajara1, Adelani David Olusegun2 and Ojekunle Oluseyi Opeyemi1


The application of leguminous agroforestry tree species using leafy biomass to improve soil fertility in the savanna alfisols is observed to be uncommon. Although, if applied, leguminous leafy biomass increases soil organic matter and improves its fertility potentials for crop productivity. This research investigated leaf-litter decomposition and nutrient release of some selected agroforestry tree species. Five species of agroforestry tree leafy biomass were selected (Faidherbia albida, Leucaena leucocephala, Gliricidia sepium, Senna siamea, Albizia lebbeck) and the effect of the biomass placement patterns of the litter bags in the soil was investigated; viz-a-viz surface placement (above-ground level) and embedded placement at 15cm depth (below-ground level) arranged as 5×2 factorial in Randomized Complete Block Design with four replicates. The data were analyzed using Analysis of Variance, while the means were separated using Duncan Multiple Range Test (p≤0.05). The soil results showed that the pH of the study area was near neutral (6.20) and loamy sand in nature.

The leafy biomass of all the agroforestry tree species tested were noted to release nutrients two weeks after decomposition. However, it was observed that the species of leafy biomass and placement patterns had significant influence on both weight loss and nutrient release. The rate of leaf-litter decomposition and nutrient release (mineralization) were significantly higher in biomass embedded in soil at 15cm depth (below-ground level) than the surface placement (above-ground level). The nutrients released in the form of nitrogen, phosphorus, potassium, calcium, magnesium, sodium and organic carbon from leafy biomass embedded in the soil reached more than 50% in the 14 days of biomass decomposition. G. sepium leafy biomass among other species decomposed and released nutrients more rapidly, both at embedded and surface placements. It is therefore recommended that G. sepium leafy biomass be used as an alternative organic based fertilizer to improve soil fertility for increased crop production in savanna alfisols.

Keywords: Leaf residues, decomposition, mineralization, soil fertility, alfisols

Annals of Tropical Research 44(2):1-16(2022)
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