Category Archives: Volume 30 No. 1 (2008)

Research Note: Stream water quality of a Community-Based Forest Management (CBFM)-protected watershed in Baybay, Leyte, Philippines

Author: Arturo E. Pasa


The study assessed the quality of stream water of the watershed within the Community-Based Forest Management (CBFM) Project in Cienda, Gabas, Baybay, Leyte, Philippines. Results showed that, on the average, streamflow velocity was 0.30m/sec, streamflow volume 0.32m3/sec, turbidity 2.96 ntu and the associated sediments 16.0 mg/ L. Odor and taste were unobjectionable. pH ranged from 7.50 to 7.0 while total hardness from 7.84 to 15.16 mg/L. The average nitrite (NO2) content was 11.115mg/L while nitrate (NO3) was 1.05 mg/L. The concentration of nutrients was also very low. Phosphorous (P) ranged only from 2.20 to 4.46 mg/kg or parts per million (ppm) while potassium (K) ranged from 3.71 to 3.90 ppm. Sodium (Na), calcium (Ca), and magnesium (Mg) concentrations were also very low. Heavy metals were detected but also at low concentrations.

Annals of Tropical Research 30(1):137-146(2008)

Research Note: Coverage of climate change risks in leading Philippine newspapers

Author(s): Rick-Angelo Piamonte and Rotacio S. Gravoso


The study aimed to find out the coverage of climate change risks in Philippine leading newspapers – Philippine Daily Inquirer, Philippine Star, and Manila Bulletin. The sample issues were from those published from January to December 2007. Results showed that the sample newspaper issues had 401 articles on climate change risks. Of these articles, the biggest number was related to education and the least was on species extinction. The one-way ANOVA showed that the three national dailies were not significantly different in terms of the number of climate change risk articles. Results also revealed that the three newspapers did not give prominence to climate change risk articles. Aside from the small space allocated, most of these articles were placed in inside pages. Experts were the most common sources of information for the articles.

Keywords : climate change communication, content analysis, news media, global warming, Philippine media

Annals of Tropical Research 30(1):125-136(2008)

Research Note: Optimizing wheat productivity through improved techniques for in situ moisture conservation in a micro watershed under sub-tropical region of North-Western India

Author(s): Sanjay Arora1 and M. S. Hadda2


The sub-montane rainfed region of North-West India has sloping topography, poor soil structure, deep water table and suffers from uneven distribution of rainfall in space and time. In an on-farm experiment on wheat conducted in the foothill region of Punjab, soil moisture storage increased to 7.7, 12.8 and 15.4% in treatment T2 (minor land shaping + NPK), T3 (T2 + 25% N replacement through FYM) and T4 (T3 + ridge sowing + Zn + herbicides), respectively, over T1 (farmers’ practice as control). Maximum increase in plant height of 28.7 per cent was observed in T4 followed by 19.9% in T3 and 13.6% in T2 treatment compared to T1. Number of grains per ear increased by 14.6, 25.1 and 33.7% through T2, T3 and T4 treatments, respectively over that in treatment T1. The grain and straw yield of wheat significantly increased by 38.6 and 65.3% in T2, 56.3 and 76.6% in T3 and 63.3 and 88.2% in T4 treatment respectively over T1 treatment (control). Maximum monetary returns were obtained in T4 treatment.

Keywords : conservation, nutrient management, rainfed, soil moisture, Punjab, wheat, yield,

Annals of Tropical Research 30(1):113-124(2008)

Appropriation of the information and communication technologies by farmers and extension workers in Borongan, Eastern Samar

Author(s): Ulderico B. Alviola and Editha G. Cagasan


This study aimed to describe how the information and communications technologies (ICTs) are being appropriated or adapted by farmers and extension workers to fit their day-to-day activities and to find out the consequences of using ICTs from the point of view of farmers and extension workers.
This study followed a qualitative case study design. Informants were identified using the snowball sampling technique. A total of 23 informants were interviewed, 13 of which were farmers and 10 were extension workers. Data were gathered using in-depth and unstructured interviews.
The grounded theory analysis was used to generate a model that describes how ICTs are appropriated by farmers and extension workers in Borongan, Eastern Samar. As shown by the model, the primary intentions for using ICTs were not agriculture-related. But because of certain facilitating factors, ICT use was later modified to fit the needs and lifestyle of farmers and extension workers. Their use of ICTs for agricultural purposes led to the following consequences: 1) savings in money and time; 2) fast access to information and instant communication; 3) convenience; 4) increased knowledge; 5) easier and faster accomplishment of job; 6) improved livelihood; 7) lessening of worries, dismay and embarassment; 8) increased demand for information and technical assistance from clients and 8) people’s increased interest to learn.

Keywords : farmers’ and extension workers ICT use, benefits of ICT, effect of ICT, Samar

Annals of Tropical Research 30(1):93-112(2008)

Effects of the mechanical factors on the peeling of cassava

Author(s): Jesus G. Sagragao1 and Daniel Leslie S. Tan2


This study was conducted to determine the effects of the clearance distance angular speed and direction of rotation of the rollers to the mechanical peeling of cassava. A device consisting of two furrowed rollers with straight corrugations about 2 mm deep, lever root presser and driving mechanism all attached to the frame was evaluated according to its peeling recovery and degree of peeling at the following factor combinations: clearance distance between rollers at 80% and 90% of the diameter of the roots, three angular speed combinations at 175 x 144 rpm, 175 x 180 rpm and 175 x 405 rpm and directions of rotations (the same and opposite) of the rollers. The Lakan variety of cassava was used in the evaluation. The cassava root with at least uniform diameters of 35 mm, 50 mm and 65 mm was fed individually, parallel to the axial rotation of the rollers then pressed to the rollers. Results indicated that the efficient peeling of the cassava roots was attained at 175 x 405 rpm at the 90% clearance distance of the same direction of rotation of the rollers.

Keywords : cassava peeling, mechanical factors, rollers

Annals of Tropical Research 30(1):72-92(2008)

Pollen morphology and viability of some Indian mangroves

Author(s): Suparna Gupta1, Arunima Ghosh1, Subrata Maity1 and Sauren Das1


A study on pollen morphology of four common Indian mangroves from Sundarbans mangrove swamps, three species from the family Rhizophoraceae (Bruguiera sexangula Laur., Ceriops tagal Perr.and Rhizophora mucronata Lamk.) and one species from the family Avicenniaceae (Avicennia marina Forsk.) was carried out. Shape of the pollen grains were prolate, prolate spheroidal and subprolate with tricolporate apertures. Surface ornamentation of the studied taxa was reticulate, finely reticulate or scabrate. Pollen grain viability of the said taxa was determined by stain test (1% aceto-orcein) under in situ condition and percentage of viable pollen production was recorded. The result revealed that all the studied taxa produce a fairly good amount of viable pollen grains in natural condition, an indication that they are good propagule producer in the long run. Pollen grain germination and measurements of pollen tube length using different sucrose concentrations (0.2, 0.6, 1.0, 1.2, 1.6 and 2.0%). Maximum pollen fertility and pollen tube length occurred in 2% sucrose solution in case of A. marina and B. sexangula, whereas 1.6% in C. tagal and 1.0% in R. mucronata. A strong positive correlation exist between pollen germination and pollen tube length, but there was a hardly relation between sucrose concentration and pollen tube length.

Keywords : mangroves, pollen morphology, pollen viability, pollen germination, pollen tube growth

Annals of Tropical Research 30(1):60-71(2008)

Altitudinal distribution of skinks along Cantubias Ridge of Mt. Pangasugan, Baybay, Leyte

Author(s): Litlen P. Dapar and Teofanes A. Patindol


The study was conducted to identify the species of skinks and to determine their distribution and abundance with special reference to elevation along Cantubias Ridge of Mt. Pangasugan. A preliminary survey was done in the two study areas to establish sites that represent the different altitude ranges from 40 to 500 m asl). Three 10 m x 20 m quadrats were laid equidistant from one another in each elevation range. Sampling and collection of specimens were done at different times of the day (9:00 A.M., 12:00 noon, and 3:00 P.M.). Basic biometric measurements were taken from the caught specimens to aid in identification.
Seven species of lizards from the family Scincidae belonging to 4 genera were identified. It was observed that more species and individuals were present in the lower elevations than at higher elevations. Temperature and light intensity decreased as the elevation increased. More number of species and individuals were encountered at higher temperature and light intensity than at lower temperature and light intensity. Sphenomorphus jagori was the most abundant and most widely distributed species while S. variegatus was least abundant and restricted only to 301-400 m asl elevation range.

Keywords : skinks, Mt. Pangasugan, altitude

Annals of Tropical Research 30(1):40-59(2008)

Research Note: Effects of leaf decomposition of selected exotic and native tree species on forest soil quality

Author(s): Cheryl C. Batistel1,2 and Victor B. Asio1


The study evaluated the effects of incorporation and subsequent decomposition of leaves of exotic tree species (Gmelina arborea, Swietenia macrophylla and Tectona grandis) and native tree species (Pterocarpus indicus, Dipterocarpus validus and Parashorea plicata) on the quality of forest soil. Forty-two pots containing an acidic and clayey forest soil and added with fresh leaves of the different tree species were setup in an open area in Mt. Pangasugan. Retrieval of the first three pots for each treatment was done after two months and the remaining three pots, five months later. Soil samples were collected from each pot and were analyzed for soil respiration rate, pH, OM, total N and available P. Findings showed that in general the exotic tree species did not change the soil pH while the native species appeared to decrease it. Regardless of tree species, leaf decomposition significantly increased available soil phosphorus. The leaves of the exotic tree species decomposed faster than those of the native tree species.

Keywords : leaf decomposition, exotic and native tree species, soil respiration rate, forest soil quality

Annals of Tropical Research 30(1):29-39(2008)

Incidence of sweetpotato viruses in Central Luzon, Philippines

Author(s): Erlinda A. Vasquez1, Manuel K. Palomar2, Lilibeth B. Laranang3 and Edgardo B. Barsalote1


Sweetpotao commercial growing areas in Central Luzon particularly Tarlac and Bataan were surveyed for the incidence of sweetpotato viruses. Healthy-looking sweetpotato leaves and those showing symptoms of virus infection were collected and subjected to nitrocellulose membrane-enzyme linked immunoabsorbent serological assay (NCM-ELISA) for the detection of known viruses using the kit and protocol from Centro Internacional de la Papa, Lima Peru. The NCM-ELISA detected sweetpotato feathery mottle virus (SPFMV), sweetpotato mild mottle virus (SPMMV), sweetpotato latent virus (SPLV), sweetpotao chlorotic fleck virus (SPCFV), C-6 virus, sweetpotato mild speckling virus (SPMSV), sweetpotato caulimo-like virus (SPCalV), and sweetpotato chlorotic stunt virus (SPCSV). Six to 8 viruses were found in Tarlac and 3-4 viruses in Bataan. Highest infections were recorded for C-6, SPMSV, SPCalV and SPCSV reaching 100% in almost all areas. Infection of SPFMV ranged from 45-70%. The combination of SPFMV with other viruses was common registering 40-70% complex infection. Mixed infection of 3-6 viruses (SPFMV, SPMMV, SPLV, C-6, SPMSV and SPCalV) was found in Tarlac and 2-4 viruses (SPFMV, C-6, SPMSV and SPCalV) in Bataan. Practically all sweetpotato growing areas of Tarlac are “hotspot” areas of sweetpotato viruses.

Keywords : sweetpotato virus diseases, identification, incidence, SPFMV, SPMMV,SPLV, SPCFV, C-6, SPMSV, SPCalV, SPCSV, serological test, NCM-ELISA, Central Luzon

Annals of Tropical Research 30(1):15-28(2008)

In vitro plant regeneration from flower stalk explants of Phalaenopsis amabilis (L.) Bl.

Author(s): Darlyn B. Posas and Marilyn M. Belarmino


An in vitro method was developed for plant regeneration of Phalaenopsis amabilis variety and hybrid using flower stalk cuttings. Experiments were conducted to overcome persistent contamination of stalks, break bud dormancy and induce regeneration of shoots. Results showed that incorporating 50 mg/l streptomycin in agar-solidified Vacin and Went (VW) medium inactivated or killed fungal and bacterial microorganisms that may have been left after sterilizing the stalks with 95% ethyl alcohol and 20% chlorine bleach. The stalk explants cultured in VW medium added with 5 mg/l benzylamino purine broke bud dormancy and induced the regeneration of shoots. The regenerated shoots exhibited three growth patterns, namely; vegetative, reproductive and dormant. The vegetative shoot produced multiple adventitious shoots in VW medium containing a combination of 5 mg/l benzylamino purine and 0.1 mg/l indole acetic acid. The regenerated shoots resembled the source plants and rooted easily in plant growth regulator-free medium. These were established in the screenhouse after acclimatization. The vegetative shoot has potential for clonal propagation of Phalaenopsis species.

Keywords : adventitious shoot, benzylamino purine, bud emergence, shoot formation

Annals of Tropical Research 30(1):1-14(2008)