Monthly Archives: October 2020

Is there a market power in the Philippine rice industry?

Authors: Maria Hazel I. Bellezas1*, Jose M. Yorobe Jr.2, lsabelita M. Paduayon2, Prudenciano U. Gordoncillo2 and Antonio J. Alcantara Jr.3

ABSTRACT Submitted: 11 December 2018 | Accepted: 09 June 2020

Rice, as a staple food for the Filipinos, is widely studied from production to consumption. However, observations of the National Food Authority domestic procurement and price stabilization policy, as well as results of the marketing and market-related studies, still reveal some gaps which call forth for an in-depth investigation and analysis. One ofthese is the possible presence ofmarket power, a market inefficiency in rice. Hence, this study aimed to ascertain the presence of market power in the Philippine rice industry. Secondary data published by the Philippine Statistics Authority from 1990 to 2015 were utilized. A structural econometric model using a time series approach was used in estimating the presence of market power. Results revealed the presence of market power in non-major rice-producing regions for well-milled and regular-milled rice in major rice-producing areas. The more the demand curve becomes inelastic the more the market power becomes apparent. The price elasticity of demand in the non-major rice-producing regions is -0.63 for both well-milled and regular-milled rice and -0.83 and -0.59, respectively, in the major rice producing areas. To minimize, if not solve market power, a substitute staple for rice may be introduced, programs/policies that will encourage more palay traders may be implemented, and farmers may be trained to operate like industry clusters.

Keywords: Bresnahan-Lau model, Market inefficiency, Price elasticity of demand, Philippine rice industry

Annals of Tropical Research 42(2):97-112(2020)
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Comparative DNA Analysis of Coconut (Cocos nucifera L.) palms with polyembryonic and monoembryonic origins

Authors: Daisy Jane A. Toting1, Tessie C. Nuñez2 and Dilberto O. Ferraren3

ABSTRACT Submitted: 6 August 2018 | Accepted: 09 June 2020

Makapuno is a rare, high-value coconut in the Philippines known for its extraordinary thick gelatinous meat with various uses in the food industry. Homozygous makapuno embryos do not germinate in vivo so plantlets are produced in vitro. where one plantlet grows from an embryo. Rare cases of polyembryony were observed in makapuno hybrids developed bythe Visayas State University, Knowledge of the genetic control of polyembryony may be used to increase the production of planting materials of these rare coconut types.

DNA analysis of two sets of twins (polyembryonic), three monoembryonic hybrid palms, and their monoembryonic parental cultivars Coconiño and tall makapuno was done using seven DNA primers to determine differences which may be associated with polyembryony in the hybrids. Polyacrylamide Gel Electrophoresis of PCR products showed DNA fragments amplified by primers CAC2 and CAC56 which are unique to the twins suggesting that polyembryony might have a genetic origin.

Keywords: Philippine Makapuno, Cocos nucifera L., polyembryony, twinning, DNA analysis

Annals of Tropical Research 42(2):21-29(2020)
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Understanding vaccine hesitancy among mothers: the case of a community hit by rubella outbreak

Authors: Rhea Jenny A. Ogalesco, Editha G. Cagasan2, Christina A. Gabrillo2 and Milagros C. Bales3

ABSTRACT Submitted: 1 October 2019 | Accepted: 09 June 2020

The Philippines has been implementing its Expanded Program on Immunization (EPI) for over 40 years now. However, measles outbreaks are still reported. One of the reasons behind this is parental vaccine hesitancy. This study aimed to understand conditions surrounding vaccine hesitancy among mothers in San Antonio, Northern Samar where rubella (German measles) outbreak was reported in 2017. A total of 1 6 mothers and three program implementers served as informants for this study. lt was found that despite the communication strategies used by the EPI program implementers, parental vaccine-hesitancy existed in the municipality. The mothers were considered vaccine-hesitant because of their delay in subjecting their children to measles vaccination. Analysis of the interview transcripts using the Grounded Theory approach revealed a number of conditions surrounding vaccine hesitancy among mothers. These include: (1) preoccupation with household responsibilities, (2) misunderstanding of the information on measles vaccination, (3) influence of social networks on vaccination decisions, and (4) negative perceptions about measles vaccination. The mothers’ hesitancy to subject their children to measles vaccination caused their children to be infected with the disease, and had resulted in an outbreak of rubella in the community. The rubella outbreak eventually led to vaccine uptake when parents realized the importance of
subjecting their children to vaccination and when the government implemented mandatory measles, mumps and rubella (MMR) vaccination.

Keywords: Vaccine hesitancy, MMR vaccination, vaccine uptake, EPI program, rubella, measles

Annals of Tropical Research 42(2):113-130(2020)
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Sensory quality of custard tart as affected by varying levels of Mabolo (Dispyros blancoi A. DC) Flesh

Authors: Loraine P. Baclayon1, Julious B. Cerna3 and Lynette C. Cimafranca2*

ABSTRACT Submitted: 1 October 2019 | Accepted: 09 June 2020

Mabolo (Diospyros blancoi A. DC) is an underutilized fruit in the Philippines. To add value and maximize the utilization of this nutritional fruit, the potential of mabolo for the production of highly saleable baked products, such as tarts, was explored. Specifically, the study aimed to formulate a custard tan filling with mabolo flesh as a flavorant using a single factor experiment arranged in a Completely Randomized Design (CRD). Six levels of mabolo flesh (0, 15, 30, 45, 60, & 75% w/w) were used. The sensory attributes for color, taste, aroma, texture, flavor, and general acceptability, were evaluated. The optimum formulation of the tart filling was determined using Regression analysis.

Results showed that mabolo custard tart filling had yellowish-brown to brown color, moderately sweet to sweet taste, and soft to slightly fibrous texture. The mabolo fruit aroma and flavor in the tarts ranged from having none to perceptible. The Analysis of Variance revealed that different levels of mabolo flesh cause a significant effect on the color (p<0.01). The optimum formulation and the recommended level of mabolo flesh in custard tart filling production was 80.54% w/w.

Keywords: tart filling, mabolo, sensory evaluation, optimization, tart

Annals of Tropical Research 42(2):85-96(2020)
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Critical fermentation factors that influence the production of multiple bacteriocins of Enterococcus faecium NKR-5-3

Authors: Rodney H. Perez1,2, Kohei Himeno2 Takeshi Zendo2 and Kenji Sonomoto2

ABSTRACT Submitted: 17 February 2020 | Accepted: 09 June 2020

Bacteriocins from lactic acid bacteria (LAB) are industrially important compounds that have been utilized as a safe food preservative replacing the potentially harmful synthetic chemical preservatives, Enterococcus faecium NKR- 5-3 is a novel LAB strain that produces five different bacteriocins‘ The critical fermentation factors, such as specific medium components and optimum incubation temperature that support the maximum production of multiple bacteriocins of strain NKR-5-3, were identified. Sucrose and yeast extract were found to be the preferred carbon and nitrogen sources for bacteriocin production of this strain, respectively. The highest bacteriocin production was observed when strain NKR-5-3 was incubated at 25°C. At incubation temperatures beyond 30°C, bacteriocin production was significantly reduced and completely ceased when further raised to 40°C, These findings possess remarkable practical implications as they can be vital in the future design of a cost-effective production system for these bacteriocins. Such a system would address the issue of the high production cost, which has remained the major barrier to the development of the large-scale industrial utilization of these important compounds.

Keywords: lactic acid bacteria, Enterococcus faecium, bacteriocin, multiple bacteriocin, bacteriocin production, fermentation factors

Annals of Tropical Research 42(2):71-84(2020)
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Qualitative traits and genetic characterization of native chicken (Gallus gallus domesticus) in selected areas of Eastern and Western Samar, Philippines

Authors: Cyrill John P. Godinez1*, Masahide Nishibori2 and Dinah M. Espina1

ABSTRACT Submitted: 10 January 2019 | Accepted: 9 January 2020

The Philippines has a number of chicken genetic groups, mostly of non-descript and indigenous type. In view of the need to expand the information on native chicken diversity, this study was conducted to identify distinct qualitative traits and estimate genetic diversity and relationship among native chicken populations in selected areas of Eastern and Western Samar, Philippines. A total of 100 native chickens were qualitatively analyzed using a non-parametric test, and 43 generated mtDNA sequences were used in the genetic analysis. Results revealed significantly different distributions of plumage color among male native chickens and shank color in female native chickens (p<0.05). The occurrence of plumage pattern, earlobe color and shank color for male native chickens and plumage color, plumage pattern, and earlobe color for female native chickens across Samar Island is not different (p>0.05). The genetic relationship showed 41.2% native chicken populations clustered to a group shared by Red junglefowl and native chicken, 29.4% clustered to a group closer to White Leghorn, and White Plymouth Rock chicken breeds, 17.6% clustered to a group shared by G. g. spadiceus and a commercial line, and 11.7% clustered to a group closer to Rhode Island Red and a commercial egg layer line. Samar native chickens had red (wild-type, e+) laced (lg) and brown (eb) pencilled (Pg) plumage in rooster and hen, respectively. The phenotypic and genetic information concluded that there is considerable diversity of native chickens in Samar, Philippines. There is a tremendous opportunity to work with larger sample size in the areas where a number of indigenous chickens have not yet been characterized.

Keywords: qualitative traits, genetic diversity, mtDNA, native chicken, Samar Philippines

Annals of Tropical Research 42(2):52-70(2020)
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Planktonic algae as bioindicators of water quality in Pagbanganan River, Baybay City, Leyte

Authors: Eunice Kenee L. Seriño1* and Beatriz S. Belonias

ABSTRACT Submitted: 11 September 2019 | Accepted: 9 June 2020

Biological monitoring is a valuable method used in conservation studies to protect and preserve the biological integrity of natural ecosystems. This study was conducted to assess the water quality of the Pagbanganan River using planktonic algae as bioindicators of organic pollution. Horizontal tows were made in three selected stations (upstream, midstream & downstream) using a Wisconsin plankton net with 80pm mesh size. Collected samples were preserved with Lugol’s solution and 70% ethyl alcohol. Identified phytoplankton genera were analyzed using Palmer’s Pollution Index. Out ofthe 20 pollution indicator genera identified by Palmer (1969), 10 were present in Pagbanganan River, namely; Ankistrodesmus, Closterium, Cyclotella, Gomphonema, Melosira, Navicula, Nitzschia, Oscillatoria, Stigeoclonium and Synedra. Four of these were among the most abundant algae in the river. Mean Palmer’s Pollution Index Scores indicate that there is “less” organic pollution existing in the river. Results imply that the river is still relatively safe for general household use, but effective conservation measures should be done to preserve the integrity ofthe river ecosystem.

Keywords: planktonic algae, bioindicators, water quality, Palmer’s pollution index

Annals of Tropical Research 42(2):43-51(2020)
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Application of Mitscherlich-Bray equation to formulate fertilizer recommendations for sweetpotato in Leyte, Philippines

Authors: Luz G. Asio1* and Nenita E. dela Cruz2

ABSTRACT Submitted: 23 March 2020 | Accepted: 28 July 2020

Until now, no studies have been conducted in the Philippines on the use of the Mitscherlich-Bray equation to formulate NPK fertilizer recommendation for sweetpotato. This study used the Mitscherlich-Bray equation to formulate NPK requirements for sweetpotato. Independent experimental set-ups of N (7 application levels), P (6 levels), and K (9 levels) arranged in RCBD with three replications were simultaneously conducted. Theoretical maximum yield, NPK constants c, and c, NPK fertilizer recommendations for sweetpotato at different soil fertility levels, and optimum fertilizer rates were calculated. Fertilizer recommendations for a common range of soil test values were developed but needed further field verification trials. Theoretical maximum yields determined by the Mitscherlich-Bray equation were 19.05, 12.66, and 14.88t ha-1 for NPK, respectively. The study showed that inherent soil fertility is vital in the development of fertilizer recommendation for sweetpotato not only to increase root yield but likewise to increase overall productivity. It showed that 30, 50, and 60 percent of the maximum possible yield was attributed to the inherent soil N, P, and K, respectively. N, P2O5, and K2O recommendations for sweetpotato were computed based on a common range of soil test values ranging from 50 to 300, 5to 40, and 200 to 700kg ha-1 NPK, respectively.

Keywords: sweetpotato, Mitscherlich-Bray equation, NPK, fertilizer recommendations

Annals of Tropical Research 42(2):30-42(2020)
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Detection and molecular characterization of phytoplasma affecting vegetables in Eastern Visayas, Philippines

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

ABSTRACT Submitted: 13 June 2019 | Accepted: 9 June 2020

Phytoplasma-like diseases were observed affecting bitter gourd, Loofah, string bean, “Baguio” bean, cucumber, and tomato in Eastern Visayas, Philippines. The infected vegetables commonly show little leaf/witches’ broom symptoms. The study aimed to detect and confirm phytoplasmas presence in these vegetables through PCR and nest PCR assays using universal primers, electron microscopy, and 16srDNA sequence analysis. Loofah little leaf had the highest prevalence (50% of the surveyed farms), followed by bitter gourd (45%) and string beans (31%). The disease had an approximate mean incidence of 27% for bitter gourd, 38.0% for Loofah, and 42.5% for string bean, in farms where plants showed infections. Electron micrographs of bitter gourd and Loofah samples showed phytoplasma cells in the phloem sieve tubes. Nest PCR assays using R1 6F2n/R16R2 primer linked to phytoplasmal6srDNA amplified a ~1.25Kb band in the majority of DNA samples. rDNA sequence analysis using Blastn showed that phytoplasmas in bitter gourd, Loofah, and one cucumber samples shared 98-99% identity with Loofah’s reference gene phytoplasma clones. More than one phytoplasma strain infected the vegetables based on Rsai enzyme digestion and phylogenetic analysis.

Keywords: witches broom, PCR, bitter gourd rDNA sequence

Annals of Tropical Research 42(2):1-20(2020)
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Management of acid sulfate soils under aerobic and anaerobic soil conditions revolves around organic matter and live plant macrophytes

Patrick Michael

Free radical scavenging activity of taro (Colocasia esculenta (L.) Schott) varieties with varying flesh color

Erlinda A. Vasquez, Precila D. Contero and Dilberto O. Ferraren

Effects of interaction between cowpea variety and the application of plant powders on Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae) infestation of stored cowpea seeds

Owolabi Moshood Azeez, Adebola Adedoyin Osipitan, Isaac Oludayo Daniel and Olufemi Olutoyin Richard Pitan

Nitrogen application improved the growth and yield performance of sweetpotato (Ipomoea batatas (L.) Lam.)

Flore-Anne C. Relente and Luz G. Asio

Adlay (Coix lacryma-jobi L.) and Napier grass (Pennisetum purpureum Schum.) intercropping and fertilization schemes as climate smart strategy for food and feed production

Nello D. Gorne and Agripina R. Aradilla

Genetic parameters of body weight in japanese quails (Coturnix japonica Temminck & Schlegel, 1849) in the Philippines

Angie R. Poliquit and Agapita J. Salces

Characterization and prediction of household use of solar home system in Leyte Islands, Philippines

Jacqueline M. Guarte, Joyce B. Maurillo and Jenefrey A. Niverba

Impact of the conditional cash transfer program`on the monthly food expenditure of household beneficiaries

Norberto E. Milla

Ultrastructure and fourier transform infrared spectrum of exopolysaccharide produced by Lactobacillus rhamnosus NBRC 3425

Ivy C. Emnace

Physico-chemical properties of dehydrated seriales (Flacourtia jangomas (Lour) Raeusch) as influenced by sugar levels

Heidi P. Paler and Lynette C. Cimafranca