Category Archives: Volume 34 No. 1 (2012)

Employment Outcomes of Graduates in Selected Higher Educational Institutions in Eastern Visayas, Philippines

Author(s): Jane A. Austero, Pedro T. Armenia and Moises Neil V. Seriño


This study aimed to describe the socio-demographic profile of graduates and determine the major factors that affect employment outcomes of HEl graduates in Eastern Visayas, Philippines. lt used secondary data from the graduate tracer studies in 2008, involving 2,097 sample graduates who were randomly selected by degree program and year graduated. Ordered logit regression was employed to determine the factors that significantly affect employment outcomes. Communication skills, human relation skills, information technology skills and problem solving skills were found to be the major skills and competencies of graduates with better employment outcomes. Moreover, graduates who earned honors and awards, had higher licensure examination rating, recommendation from influential personalities, good performance in walk-in application and appropriate response to job advertisements are more likely to be employed related to the degree taken up. Graduates in mass communication and documentation had the highest probability for the most favorable labor market outcomes, indicating that these graduates have better chances o fbeing employed related to the degree they took up.

Keywords : ordered logit regression, labor market, graduate skills, job seeking, Philippine HEI

Annals of Tropical Research 34(1):147-162(2012)

Outcomes of Learning Online: The Case of Farmers and Extension Workers in the Philippines

Author(s): Marjhurhy Ann S. Federicos and Rotacio S. Gravoso


The Philippines is now adopting information and communication technology (ICT) to promote agricultural sustainability and rural development. Among the development programs that apply ICT is the Open Academy for Philippine Agriculture (OPAPA) E-Learning Project by the Philippine Rice Research Institute (PhilRice), the agency mandated to spearhead research and development programs on rice. Following the most significant change (MSC) technique, this study was conducted to identify the most significant changes experienced by OPAPA E-Learning graduates composed of farmers, extension workers and agricultural science students. Results showed that respondents enrolled in the program to acquire knowledge of rice technologies, gain skills in operating a computer, update themselves about new farm technologies, and comply with academic and work requirements. Based on 20 MSC stories collected, the OPAPA E-Learning Project has led to the increase in knowledge of rice technologies and awareness of the program, improvement in school, farm and extension practices, and enhancement of computer skills. The Bennett Hierarchy of Program Outcomes revealed that the most significant change stories reported by the respondents correspond to higher levels of outcomes, indicating that the OPAPA E-learning Project has already made an impact in terms of improving its clientele’s knowledge and capability.

Keywords : distance learning, most significant changes, capability development,agricultural technologists, rice production

Annals of Tropical Research 34(1):129-146(2012)

Genetic Diversity and Inbreeding in a Captive Population of the North Persian Leopard (Panthera pardus saxicolor L.)

Author(s): Ana Marquiza M. Quilicot1 and Roswitha Baumung2


Information on the degree of inbreeding is very important in the effective management of captive populations of animals in zoos. For the North Persian leopard (Panthera pardus saxicolor), in particular, no report on this aspect is available. This study evaluated the effect of inbreeding on fitness traits and the possible occurrence of purging in a captive population of the leopard based on pedigree records of the Australasian Regional Association of Zoological Parks and Aquaria covering the period 1955–2008. The significance of individual, sire or dam inbreeding on individual and litter fitness traits and litter size was analyzed using linear mixed models. Results showed that individual inbreeding significantly decreased survival at days 30 and 90 (weaning age) after birth, while litter inbreeding significantly decreased litter survival at days 7, 30 and 90. There was also a corresponding decrease in litter size when the dam was inbred. Purging of genetic load is possible with increased survival of the individual and litter when the dam was inbred. However, enhanced zoo management has to be considered with increased survival of individuals. Considering the unpredictable response of traits to inbreeding, designing breeding programs for captive populations should be geared toward maximizing genetic diversity and minimizing the rate of inbreeding.

Keywords : total inbreeding, fitness traits, purging in captive populations, North Persian leopards

Annals of Tropical Research 34(1):114-128(2012)

Quantification of the Relative Virulence of White Spot Syndrome Virus(WSSV) in the Penaeid Shrimps Litopenaeus vannamei (Boone, 1931) and Farfantepenaeus duorarum (Burkenroad, 1939) by Quantitative Real Time PCR

Author(s): Rey J. dela Calzada1 and Jeffrey M. Lotz2


The relative virulence of the China isolate of white spot syndrome virus (WSSV-CN) in the penaeid shrimps Litopenaeus vannamei and Farfantepenaeus duorarum, was assessed by a comparison of 7-d median lethal dose (LD50), survival curve, and mean lethal load after exposure by injection. Shrimps were injected intramuscularly with known WSSV dose. Median lethal dose of L. vannamei was lower than that of F. duorarum. Log LD50 in L.vannamei was 4.20 WSSV genome copies μg-1 total DNA. Log LD50 in F.duorarum was 5.32 WSSV genome copies μg-1 total DNA. Median survival times of L. vannamei and F. duorarum injected with 104 and 105 WSSV genome copies were 54.17 h and 38.91 h, respectively for L. vannamei whereas they were 119.58 h and 82.67 h, respectively for F. duorarum. Mean log of the WSSV lethal load for L. vannamei was 9.34(SE ± 9.09) copies μg-1 of total DNA and for F. duorarum was 11.80 (SE ± 11.55). No significant difference was noted in lethal load for the shrimp species using Student’s t-test. Overall mean WSSV lethal load was 2.86 x 1011(SE+1.63 x 1011) genome copies μg-1 oftotal DNA. In conclusion, WSSV was found to be less virulent in F.duorarum than in L. vannamei by L50 and mean survival time but not in mean lethal load. This suggests that shrimp resistance is imparted by controlling WSSV loads rather than by tolerating higher loads.

Keywords : WSSV-China isolate, median lethal dose (LD50), median survival times, lethal loads

Annals of Tropical Research 34(1):96-113(2012)

Development of in vitro Slow Growth Culture for Yarn (Dioscoreo alata L.)

Author(s): Villaluz Z. Acedo and Catherine C. Arradaza


Germplasm collections, the lifeblood of breeding programs, are traditionally maintained in the field. Field genebanks are expensive, subject to genetic erosion, and require several quarantine measures for safe movement of genetic materials. These problems are more serious in long-duration, non-flowering and vegetatively propagated crops like yarn. This study aimed to develop a tissue culture technique for in vitro conservation of yarn germplasm. ’VU-2’ and ‘Kinampay’ varieties were used in establishing the in vitro conservation technique which was then tested to other genotypes. With the tissue culture protocol for yarn propagation developed earlier, the plantlets became overgrown after 2-3 months, requiring frequent subculturing and increasing the cost of maintenance and the risk of microbial contamination. Slow growth culture was tested using MS medium added with 0-10 mg/L abscisic acid (ABA) or 0-7% mannitol or sorbitol. Expectedly, plantlet growth slowed down. However, ABA at higher levels increased mortality of cultures while sorbitol was less effective than mannitol in retarding growth. Mannitol at 4% was found to be the best slow growth medium to maintain the plantlets for 13 months, thereby saving at least 4 times the maintenance cost using the normal growth medium. Tissue viability, morphological stability and tuber yield were not affected. Other genotypes (VU-1, VU-3, VU-4, VU-5, PR5, PR7, PR10 and PR11) responded similarly to the slow growth culture condition.

Keywords : yarn, Dioscorea alata, germplasm, mannitol, sorbitol, ABA, slow growth

Annals of Tropical Research 34(1):79-95(2012)

2-bromo-1-(2-hydroxyphenyI)-3,4-dimethyIpentan-1-one: A New Bromo-Compound with Stimulatory Activity Isolated from the Shed Leaves of Teak, (Tectona grandis L.)

Author: Suparna Mandal Biswas


A new Bromo isotopic compound has been isolated and purified from the Methanol Fraction of Teak leaves (MFTk). Chromatographic and spectral analyses (TLC, UV, MS, NMR, and IR) indicated the compound to be 2-bromo-1-(2-hydroxypheny1)-3, 4-dimethylpentan-1-one, in short, BrHPDMP with molecular weights 285 and 287. The whole leaf leachate of teak showed strong inhibitory activity in bioassay. But when fraction-4 (Methanolic fraction of teak leaf) was isolated and purified, it showed concentration dependent stimulatory activity on rice seeds. At 1000 ppm concentration, it showed 12.820% inhibition in shoot and 15.59% stimulation in root length. Below this concentration, it showed stimulatory effects on both shoot and root length. At 500ppm, it revealed 10.040% stimulation in shootlength and 34.16% stimulation in root length. At a concentration of 31.25ppm, it revealed maximum stimulatory effects i.e. 16.260% stimulation in shoot length and 42.78% stimulation in rootlength.

Keywords : teak (Tectona grandis L.), allelochemical, Bromo-compound, agroforestry species, growth stimulator.

Annals of Tropical Research 34(1):65-78(2012)

Response of in vitro Cultured Palm Oil Seedling Under Saline Condition to Elevated Carbon Dioxide and Photosynthetic Photon Flux Density

Author(s): Pet Roey Pascual1, Krienkai Mosaleeyanon2, Kanokwan Romyanon2 and Chalermpol Kir dmanee2


Salt stress elicits various physiological and growth responses of oil palm. A laboratory experiment was conducted to determine the responses of oil palms cultured in vitro under varying salinity levels (0, 85.5, 171.11, 342.21 and 684.43 mM NaCl) to elevated CO2 (1000 μmol CO2/mol) and PPFD (100±5 μmol m-2s-1) in terms of growth characteristics, pigment contents and photosynthetic abilities. After 14 days of culture, net photosynthetic rate (μmol CO2 m-2s-1) of oil palms across varying salinity levels was 5.33 times higher than those cultured under ambient CO, (380±100 Mmol CO2/mol) and PPFD (50±5 μmol m-2s -1). At increased net photosynthetic rate (elevated CO2 and PPFD), despite having no significant difference in pigment contents (chlorophyll a, chlorophyll b, total chlorophyll and carotenoid) between different CO2 and PPFD levels, dry weight and percent dry matter were 0.26 and 0.11 times higher, respectively, as compared to those cultured under ambient CO2 and PPFD. In the same elevated CO2 and PPFD level, across all salinity levels, stomatal conductance was 0.30 times lower than those cultured under ambient CO2 and PPFD. At reduced stomatal conductance (elevated CO2 and PPFD), transpiration rate was also reduced by 0.30 times. Thus with increased net photosynthetic rate and reduced transpiration rate, water use efficiency was increased by 7.22 times, across all salinity levels, than those cultured at ambient CO2 and PPFD. These were considered essential for NaCl produces iso-osmotic stress.

Annals of Tropical Research 34(1):52-64(2012)

Comparative Performance of Biofertilizers on Irrigated Lowland Rice (Oryza sativa L.)

Author(s): Michelle B. Castillo and Cezar P. Mamaril


Biofertilizers have been claimed as an alternative source of nutrients for plants in order to increase yield and reduce the inorganic fertilizer use by 500%. Sixteen trials were undertaken nationwide covering the provinces of Ilocos Norte, Isabela, Nueva Ecija, Laguna, Camarines Sur, Negros Occidental, Leyte, Samar, Bohol, Agusan, and North Cotabato during wet and dry seasons of 2008-2010 to verify the effectiveness of biofertilizers (Bio N, Vital N, BioCon) under lowland or anaerobic ecosystem. The experiment consisted of nine treatments which included control, and biofertilizers applied alone or in combination with inorganic fertilizers either at one-half or full recommended rate. Generally, biofertilizers evaluated showed no positive effect on grain and straw yields of lowland rice and yield components such as plant height, tiller count, number of productive tillers, spikelet count, number of filled grains and unfilled grains, and weight of 100 grains. The positive effect of BioCon, Vital N and Bio N on root length at seedling stage may be attributed to the microorganisms producing plant growth hormones which might have enhanced root growth under “dapog” seedbed condition. However, the beneficial effect on root growth was not sustained and reflected in the yield when the seedlings were transplanted in the field. Generally, results show that biofertilizers evaluated were not effective under anaerobic condition.

Keywords : anaerobic condition, biofertilizers, microorganisms, root growth

Annals of Tropical Research 34(1):29-51(2012)

Nutrient Uptake and Fiber Yield of Abaca (Musa textilis var. Laylay) as Affected by Shade, Irrigation and Fertilizer Application

Author(s): Marlito M. Bande1,4, Jan Grenz2, Victor B. Asio3 and Joachim Sauerborn4


Abaca, being a shallow rooted plant and a gross feeder, is able to exploit a limited zone soil. Hence, a careful evaluation of its nutrient uptake is needed, particularly under reduced light condition, irrigation, and NPK fertilization. These field trials were performed to investigate the effect of different shade conditions, irrigation, and fertilizer application on NPK plant uptake and fiber yield of abaca. Light infiltration was reduced by 30%, 40%, and 50% of full sunlight using polypropylene shade nets. Irrigation was applied at a rate of 5 liters plant” application” day”. Placement application of N, P2O5 , K2O using complete fertilizer was done at 14 grams plant-1 quarter-1 for the first six months and was increased to 40 grams plant-1 quarter-1 for the next six months after planting. Results showed that shade (p ≤ 0.01) and irrigation- fertilization (p ≤ 0.05) significantly influenced NPK plant uptake, root and leaf uptake rates of abaca from seedling stage until flagleaf stage. The amount of NPK absorbed was proportional to the amount of growth made as influenced by shade and irrigation- fertilization at different stages of plant growth. The abaca grown in 0% shade was negatively affected by high radiation causing photoinhibition and photooxidative damage of the crop at seedling and early vegetative stages that significantly affected NPK uptake rates and fiber yield. The combination of irrigation and fertilization could further enhance fiber yield to as much as 41% but this was not enough to offset the effects of shade on the growth performance and NPK plant uptake of abaca which significantly (p < 0.01) increased fiber yield to as much as 165%.

Keywords : nutrient uptake rates, photoinhibition, photooxidative damage, fiber crop, shade, irrigation-fertilization

Annals of Tropical Research 34(1):1-28(2012)