Home

Current Issue

Editorial Board

Past Volumes

Subscription & other information

Information for
Contributors

Vol. 87 No. 4 (December 2004)

ABSTRACTS OF ARTICLES

Volume 87

TABLE OF CONTENTS

Philipp Agric Scientist 87: 373-382 (2004)

Comparative Evaluation of the Effects of Fish Silage Mixed Diets

IN LAMBS

Antonio J. Barroga ¹*, Rajeev Pradhan ² and Hisaya Tobioka ³

¹ Department of Animal Science, Central Luzon State, Science City of Muñoz, Nueva Ecija, Philippines

^{2, 3} Department of Animal Science, College of Agriculture, Kyushu Tokai University, Kumamoto, Japan

*Author for correspondence; e-mail address: tony_barry@yahoo.com

Two separate experiments were done to determine the effectiveness of dietary manipulation of fish silage as protein supplement and compare it with fish meal and urea using sorghum silage (Experiment 1) and Italian ryegrass silage (Experiment 2) as basal rations. The fish silage consisted of the minced head, backframe and viscera of yellow tail (Seriola quinqueradiata). In Experiment 1, the molar propionate ratio in sheep fed with the fish silage supplement was higher than that of the fish meal and urea supplements (P<0.05) 4 h after feeding. In Experiment 2, however, it was reduced to 21.7 %. In contrast, the organic matter intake in the diet of sheep fed with fish silage supplement remarkably improved the digestibility of crude protein and the organic matter intake of sheep fed with fish silage tended to be higher than those of sheep fed with the urea and fish-meal-supplemented diets. The nitrogen balance of the fish silage using sorghum silage was significantly lower than that of the fish meal but was comparable with that of the urea supplement. On the other hand, the urinary purine derivative excretion and the microbial nitrogen production of sheep fed with the fish silage consisting of Italian ryegrass silage as the basal ration was comparable to those of sheep fed with the fish meal and urea supplements. These results suggest that the fish silage in Experiment 2 can be a potential protein supplement for growing lambs.

Philipp Agric Scientist 87: 383-395 (2004)

CROP YIELDS AND DYNAMICS OF SOIL ORGANIC MATTER, NITROGEN,

PHOSPHORUS, POTASSIUM, MICROBIAL BIOMASS N AND MICROORGANISMS

AS INFLUENCED BY BIO-ORGANICS

Ireneo J. Manguiat ¹* and Patrick M. Rocamora ²

¹ Agricultural Systems Cluster (ASC), ² College of Agriculture, University of the Philippines Los Baños (UPLB), College, Laguna 4031, Philippines

*Author for correspondence; e-mail: dss@laguna.net

Field experiments were conducted for 3 yr to assess the influence of bio-organics on: (a) the yields of various crops and (b) the dynamics of NPK, organic matter, microbial biomass N (MBN) and microbial populations. Bio-organics significantly improved the average yield of six crops for 3 continuous yr over the control by 98% but the improvement was much higher (153%) when 50% of the chemical fertilizer N was substituted with bio-organics N. For the chemical fertilizer N, however, the average yield increment over the control for the six crops was 195%. While a 50:50 proportion of bio-organic and inorganic fertilizer was helpful, it would take sometime for the yield to be comparable with that of purely inorganic fertilizer. Furthermore, it is not advisable to suddenly shift from inorganic to completely bio-organic fertilizer since it would substantially decrease the yield.

Soil organic matter declined continuously following a quadratic pattern except for the bio-organics treatment. The addition of N from either inorganic fertilizer or bio-organics increased the total soil N initially but after 21 cropping months, its level started to decline. Available P increased with bio-organics addition during the first 21 cropping months but a rapid decline was observed afterwards. The levels of exchangeable K decreased exponentially throughout the cropping months regardless of fertilizer treatments. MBN increased quadratically as a result of the application of either inorganic fertilizer or bio-organics and it was positively and significantly correlated with the yields of pechay and green corn. Bacterial population responded positively to bio-organics addition and bacteria appeared to be more sensitive than either actinomycetes or fungi as microbial indicator of soil environmental quality in continuously cropped production systems.

Philipp Agric Scientist 87: 396-407 (2004)

INFLUENCE OF COPPER MINE TAILINGS ON THE SOIL FERTILITY STATUS

AND GROWTH OF RICE IN LUZON, PHILIPPINES

Henry P. Samonte ¹* and Apolonio M. Ocampo ²

¹ Agricultural Systems Cluster and ² Institute of Plant Breeding, respectively, College of Agriculture, University of the Philippines Los Baños, College, Laguna 4031, Philippines

* Author for correspondence

The lack of local empirical data to answer questions on the effects of possible depositions of copper mine tailings on the production of some agricultural alluvial floodplains along the Boac River in Marinduque, Philippines, led to the conduct of this research with the following objective: to determine the influence of copper mine tailings and fertilization on soil chemical properties, grain yield, nutritional status and nutrient uptake, including some heavy metals, of lowland rice.

For the characterization of mine tailings and soil profiles, bulk samples were collected in Hinapulan, Bamban and Daypay, Marinduque.  Two field experiments were conducted for three seasons on a Maranlig clay in San Antonio.

The addition of 5-20 cm tailings resulted in lower organic matter, lower cation exchange capacity (CEC), increase in pH up to 4.26 which was still extremely acidic, high exchangeable Cu which was within the phytotoxic range in soils, higher available P, critical K level and slight increase in Cd and Zn but which were below the critical phytotoxic level.

The low grain yields in the soils with 5-cm and 20-cm thick mine tailings were corrected with 130-240-180 kg N-P2O5-K2O per hectare.  At this fertilization rate, grain yields were significantly higher and were not adversely affected by the thickness of the mine tailings.  The average nutrient requirement for plants producing 5 tons grain per hectare was 127-78-121 kg N-P2O5-K2O per hectare.

With the use of fertilizer, the concentrations of N, P and K in the grain and straw were not significantly affected by thickness of the mine tailings.  The nutrient concentrations were significantly lower when fertilizer was not used and only the N concentration was significantly lowered by the 5- to 20-cm mine tailings.  Copper in the grain was slightly higher with the 20 cm tailings added.  Zinc concentration was also higher in the 20 cm tailings added but these were within the allowable range in cereal foodstuff.  The cadmium concentration ranging from 0.5 to 1.0 mg kg-1 reached the allowable limit of 1 mg kg-1 for unpolished rice but it was below the 2 mg kg-1 concentration in the diet that is considered toxic to man.  The concentrations of Cu, Zn and Fe in the straw increased with thickness of the mine tailings but these were below their respective critical phytotoxic level.  The mine tailings had no significant effect on the cadmium in the straw.  Manganese concentration in the straw increased with thickness of mine tailings, exceeding the lower limit of the phytotoxic level in rice.

On a Maranlig clay treated with 20-cm tailings, fertilization with 130 (CAF)-240-0 or 130-240-180 increased the yield significantly compared to the unfertilized rice.  The yield increments were comparable with that of the fertilized soil alone.

Philipp Agric Scientist 87: 408-416 (2004)

HIGH RATES OF ABSORPTION OF TRIASULFURON IN HIGH pH soils are due to greater HERBICIDE availability rather than a physiological response

Juanito V. Bariuan

National Crop Protection Center, College of Agriculture, University of the Philippines Los Baños, College, Laguna 4031, Philippines

Chlorsulfuron and triasulfuron are two sulfonylurea herbicides used for selective control of weeds in wheat, rice and other grass crops.  Rates of application should be lower if the soil pH is near or above neutral to avoid phytotoxicity to the present crop and injury to other crops in succession.  Increased absorption and phytotoxicity at high pH could be due to exposure to higher concentrations over a longer time because of less adsorption and slower hydrolysis of these sulfonylureas at high pH.  Plant factors may also contribute to phytotoxicity at high pH.

The pH was manipulated in soil and solution culture to investigate the response to pH of triasulfuron absorption by wheat (Triticum aestivum cv.  Kulin).  Absorption at 18 C by seedlings (at the 4-leaf stage) in solution culture from a 5-h pulse of triasulfuron decreased from 0.4 to 0.2 µg g-1 plant fresh weights when pH was increased from 5.0 to 6.5 for the duration of the pulse; there was no influence on absorption when the seedlings were defoliated.  Wheat was grown in acid (pH 4.9) and near-neutral (pH 6.8) sandy soils in which pH was adjusted to 7.0 and 5.0, respectively, 11 wk before sowing and to which 14C-triasulfuron was added at 0 and 50 µg kg-1 soil immediately prior to sowing.  Mean rates of absorption/mean plant fresh weight (RA) were calculated for 30 d after sowing.  Most of the absorbed 14C was in the roots with less than 5% in the shoots of any treatment.  The RA in the acidic soil increased from 2.7 to 14.4 Bq d-1 when pH was adjusted from 4.9 to 7.0 and the RA for the neutral soil decreased from 11.7 to 3.1 Bq d-1 when the soil was acidified from pH 6.8 to 5.0.  The RAs did not differ between the soils at the same pH.  Significantly more triasulfuron was adsorbed in acidic than in near-neutral soils.  Increased phytotoxicity of the sulfonylureas at high soil pH is due to the greater availability of higher proportions of the applied dose in the soil solution rather than an effect on the physiology of absorption.  Consequently, the higher phytotoxicity at high soil pH can be ameliorated by reductions in the rates of application.

Philipp Agric Scientist 87: 417-426 (2004)

TRANSLOCATION OF 14CO2 AND 14C-DEOXYGLUCOSE IN BRACKEN (Pteridium esculentum Forst. f. Cockayne): IMPLICATIONS FOR HERBICIDE EFFICACY  

M. M. Loresco ¹*, D. F. Chapman ² and R. D. Cousens ³

¹ Forage & Pasture Crops Section, Dairy Training and Research Institute, College of Agriculture, University of the Philippines Los Baños, College, Laguna 4031, Philippines

² School of Agriculture and Food Systems, and ³ School of Resource Management, Institute of Land and Food Resources, The University of Melbourne, Victoria 3010, Australia

*Author for correspondence; e-mail: mml@mudspring.uplb.edu.ph

The translocation of photoassimilates and foliarly applied chemicals in glasshouse-grown Australian bracken (Pteridium esculentum Forst. f. Cockayne) was investigated using two radiotracer techniques: (1) pulse labeling of 14CO2 in enclosed fronds and (2) application of 14C-deoxyglucose using a microsyringe in fully expanded frond.  In the first experiment, the translocation and distribution of 14CO2 was determined in the different parts of 4-mo-old bracken, where either the young or old frond was pulse-labeled with 14CO2.  In the second experiment, the effects of pretreatment application of plant hormones (kinetin or ethephon) in the translocation and distribution of 14C-deoxyglucose and metsulfuron-methyl applied concurrently on 1½-yr-old bracken plants with extensive rhizome system was investigated. 

Fully expanded fronds function as source while rhizome apices, frond buds and unexpanded fronds are the main sinks.  A relatively low proportion of fixed 14C was exported from fed fronds, and the rhizome system was the dominant sink for exported   14C.  The two radiotracer experiments differed in the amounts of radiolabel exported to the different parts of bracken due to differences in plant age and size of bracken plants used.

Both experiments confirmed that the direction of translocation follows the photoassimilate pathway to actively growing meristems, e.g., rhizome buds and apices and rapidly expanding fronds.  The application of plant hormones enhanced the translocation of 14C-deoxyglucose in the rhizome system, presumably a result of altered source: sink ratios due to stimulation of  metabolic activity in the subterranean part of the weed.

The similarities and differences between the two radiotracer experiments were discussed and potential implications for increasing the efficacy of the chemical control of bracken were noted. 

Philipp Agric Scientist 87: 427-438 (2004)

Identification and characterization of bacteriocinogenic Lactobacillus plantarum BS25 isolated from Balao-balao, a locally fermented rice-shrimp mixture from the Philippines

C. G. B. Banaay ¹*, F. B. Elegado ² and I. F. Dalmacio ³

¹ Environmental Biology Division, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, College, Laguna 4031, Philippines

² National Institute of Molecular Biology and Biotechnology (BIOTECH), University of the Philippines Los Baños, College, Laguna  4031, Philippines

³ Microbiology Department, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, College, Laguna 4031, Philippines

*Author for correspondence; e-mail: gbanaay@lb.msc.net.ph

Out of 1,100 putative lactic acid bacteria (LAB) isolated from selected indigenous fermented foods in Luzon in the Philippines, one isolate, which possessed the largest zone of inhibition and the widest antimicrobial spectrum among the isolates, was selected for identification and characterization. Identification of the isolate was done using conventional morphological, biochemical and physiological methods, chemotaxonomic methods, as well as molecular methods. The polyphasic methodologies employed led to the identification of the bacteriocin-producing isolate as Lactobacillus plantarum. The bacteriocin production of the isolate was then further evaluated.

Lactobacillus plantarum BS25 produced more bacteriocin in filter-sterilized modified MRS broth incubated at 30 C than in the steam-sterilized counterpart incubated under the same conditions. It was able to produce large amounts (1920 AU mL-1) of bacteriocin when the pH of the filter-sterilized culture media was adjusted to pH 5, 6, 7 and 8. Examination of changes in pH, cell count and bacteriocin activity revealed that the bacteriocin is produced as a primary metabolite. Production of large amounts of bacteriocin was accompanied by a large cell count and a decrease in pH to lower than 4.5.

Philipp Agric Scientist 87: 439-451 (2004)

Understanding the biotechnology debate through “symbolic confrontations” or reportage in the print media will thus lead to more appropriate communication modalities that address specific issues around which public opinion forms.

Mariechel J. Navarro* and Monina A. Villena

Global Knowledge Center on Crop Biotechnology, International Service for the Acquisition of Agri-biotech Applications,  ISAAA  Southeast Asia Office, Khush Hall, International Rice Research Institute, Los Banos, Laguna, Philippines

*Author for correspondence; e-mail:m.navarro@isaaa.org

A media monitoring survey of national daily English newspapers in the Philippines in 2002 and 2003 revealed that journalists are writing about biotechnology, find it important enough to merit space and coverage, and follow developments in the biotechnology arena. Three important milestones on agri-biotechnology were reported extensively in the country. These were the signing of the Philippines’ Department of Agriculture Administrative Order No. 8 in April 2002 on the rules and regulations for the importation and release into the environment of plants and plant produce derived from the use of modern biotechnology, the approval of the first genetically modified (GM) crop or Bt corn in the Philippines and Asia in December 2002; and the hunger strike against the commercialization of Bt corn in May 2003.

A media monitoring study conducted by the Global Knowledge Center on Crop Biotechnology of the International Service for the Acquisition of Agri-biotech Applications (ISAAA) in collaboration with country network contacts scanned national papers and analyzed monthly summaries of news stories that were featured between January 2002 and May 2003. Stories were analyzed according to topic, theme, tone and source of information.

Nine national English dailies published a total of 446 articles for a 17-month period or a monthly output of 26 articles. The three major newspapers (Manila Bulletin, Philippine Star and the Philippine Daily Inquirer) accounted for 61% of all articles published. Generally, articles were positive, supportive of government and private sector initiatives and guided by social/cultural interest. Topics on government regulations dominated the articles in agri-biotech due to government approval of guidelines related to the use of genetically modified organisms and approval of the first GM crop for commercialization.

Philipp Agric Scientist 87: 452-456 (2004)

RESEARCH NOTE: SOME ECONOMIC PLANTS SUGGESTED FOR CULTIVATION

AT DIFFERENT ALTITUDES OF MT. BANAHAW DE LUCBAN, QUEZON, Philippines

Eustaquio G. Aragones, Jr. ¹* and Wilfredo C. Faller ²

¹ Department of Science and Technology (DOST), Bicutan, Taguig, Metro Manila. On detail to the Forest Products Research and Development Institute (FPRDI), College, Laguna 4031, Philippines

² Department of Forestry, School of Agriculture, Southern Luzon Polytechnic College (SLPC), Lucban, Quezon, Philippines

* Author for correspondence; e-mail: lee_bug21@yahoo.com

Economic plants with commercial or market value which can be successfully grown at medium and high altitudes of the Malesian region (Malay Federation, Indonesia, the Philippines, New Guinea and the Lesser Sunda Islands) were compared with crops planted in Mt. Banahaw by the farmers of Lucban, Quezon, Philippines. Based on their altitudinal growth range, similar and new crops were suggested for cultivation at different altitudes and sites in Mt. Banahaw de Lucban to augment the people’s traditional crops and for better use of the mountain’s land resources.

Philipp Agric Scientist 87: 457-462 (2004)

RESEARCH NOTE: PLANT REGENERATION VIA DIRECT SHOOT ORGANOGENESIS FROM COTYLEDON AND COTYLEDONARY NODE EXPLANTS OF POLE SITAO (Vigna unguiculata {L.} Walp. var. sesquipedalis {L.} Koern.)

Renato A. Avenido ¹*, Julita G. Dimaculangan ¹, Julie N. Welgas ¹ and Edwin E. del Rosario ²

¹ Plant Cell and Tissue Culture Laboratory, Institute of Plant Breeding, College of Agriculture, University of the Philippines Los Baños, College, Laguna 4031, Philippines

² Feed and Industrial Crops Division, Institute of Plant Breeding, College of Agriculture, University of the Philippines Los Baños, College, Laguna 4031, Philippines

*Author for correspondence; e-mail: raavenido@yahoo.com

A complete system for in vitro shoot induction, rooting and ex vitro establishment for pole sitao (Vigna unguiculata {L.} Walp. var. sesquipedalis {L.} Koern.) was established for the first time using the protocol for mungbean and other Asiatic Vigna spp. as the basis.  Cotyledon and cotyledonary node (CN) explants from aseptic seedlings were cultured using Murashige and Skoog (MS) salts and B5 vitamins medium with 1.0 and 2.0 mg L-1 benzyladenine (BA).  On the average, percentage shoot formation in cvs. UPL PS 1 and UPL PS 2 was higher using CN (67.6% and 80.4%) compared with using cotyledons (25.2% and 17.8%).  However, higher responses of 52.5% to 60.0% were obtained when cotyledons from younger seedlings (1 to 3 d) were used.  Shoot regeneration from CN explants of eight cultivars and advanced breeding lines revealed that the response is genotype-dependent with lines 62001, 62005 and 62012 exhibiting 97.0% to 100% shoot regeneration.  Regenerated shoots excised from explants were rooted at high frequencies (80% to 100%) and survival of rooted regenerants in soil-coir dust mixture under greenhouse conditions ranged from 50% to 100%.  Tissue-culture-derived regenerants from cvs. UPL PS 1 and UPL PS 2 and lines 62001, 62005 and 62012 were all morphologically normal, they flowered and produced pods filled with fertile seeds upon maturity.

Philipp Agric Scientist 87: 463-467 (2004)

RESEARCH NOTE: FRUIT VARIABILITY AND CORRELATION ANALYSIS OF SOME PHENOTYPIC CHARACTERS IN AVOCADO (Persea americana Mill.), RAMBUTAN (Nephelium lappaceum L.) and SWEETSOP (Annona squamosa L.)

P. M. Magdalita* and L. D. Valencia

Institute of Plant Breeding, College of Agriculture, University of the Philippines Los Baños, College, Laguna 4031, Philippines

*Author for correspondence; e-mail: pab@lgn.csi.com.ph

The fruit characters of 100 genotypes each of avocado (Persea americana Mill.), rambutan (Nephelium lappaceum L.) and sweetsop (Annona squamosa L.), propagated using seeds, were evaluated and analyzed. The variability is wide for fruit weight, length and width, seed weight and peel thickness in avocado; fruit weight and length, seed weight total soluble solids and percent edible portion in rambutan; and fruit weight, length and width, total soluble solids and percent edible portion in sweetsop. Conversely, the variability is narrow for flesh thickness, seed weight, length, peel weight and percent edible portion in avocado; fruit width, flesh thickness, seed length and width and peel weight in rambutan; and flesh thickness and total seed weight per fruit in sweetsop. Fruit weight, the most important character being considered in the selection of elite genotypes, is correlated with fruit width and seed weight in avocado, fruit length, fruit width and seed weight in rambutan, and fruit width and flesh thickness in sweetsop. Other character combinations that are correlated are: flesh thickness and percent edible portion in avocado, fruit length and fruit width in rambutan, and fruit width and flesh thickness in sweetsop. The frequency distribution of fruit weight is positively skewed towards the lower fruit weight values in avocado, rambutan and sweetsop.

Philipp Agric Scientist 87: 468-472 (2004)

RESEARCH NOTE: CYTOGENETICS OF THE MANGO LEAFHOPPER, Idioscopus clypealis

(Lethierry) (Hemiptera: Cicadellidae)

Katherine Ilagan ¹, Rita P. Laude ¹*, Virginia R. Ocampo ² and Luisa N. Villamael ¹

¹ Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, College, Laguna 4031, Philippines

² Department of Entomology, College of Agriculture, University of the Philippines Los Baños, College, Laguna 4031, Philippines

* Author for correspondence; e-mail: rplaude@yahoo.com

The chromosome number and meiotic index of the mango leafhopper, Idioscopus clypealis (Lethierry), were determined and the chromosome behavior at various stages of meiosis was analyzed.  Based on chromosome counts done on 40 meiocytes at diakinesis, 75% of the meiocytes had a haploid chromosome number of 10 (n = 10) and 25% had a haploid chromosome number of 9 (n = 9).  The chromosomes were holocentric, bivalent and appeared as thick, darkly stained bodies with an average relative length of 0.54 (range = 0.23 to 1.00 at pachytene).

Average meiotic index of I. clypealis was 89.7% (range = 85% to 94%); meiotic chromosomal behavior was relatively normal.  The centromeric index was no longer investigated due to the holocentric behavior of the chromosomes.  Clumping of chromosomes was observed at metaphase I (63%) and metaphase II (30%) and bridge formation at anaphase I (31%).  The frequency of chromosomal abnormalities decreased as meiosis progressed.

Philipp Agric Scientist 87: 473-476 (2004)

THE ANTIMICROBIAL ACTIVITY AND EFFECT OF HEAVY METALS ON THE BIOLUMINESCENCE OF BIOLUMINESCENT BACTERIA FROM THE GASTROINTESTINAL TRACTS OF PHILIPPINE MARINE FISHES

Lilibeth January R. Garcia and Esperanza C. Cabrera*

Biology Department, De La Salle University, 2401 Taft Ave., Manila, Philippines

*Author for correspondence; e-mail:  cabrerae@dlsu.edu.ph

Bioluminescent bacteria isolated from the gastrointestinal tracts of fresh marine fishes locally known as alumahan (Rastrelliger sp.), matambaka (Selar crumenopthalmus), besugo (Nemipteris sp.), tamban (Sardinella sp.) and sap-sap (Leiognathus bindus) obtained from the Baclaran Seaside Market in Pasay City, Philippines were tested for the presence of antimicrobial activities. Twenty-one of the 34 isolates studied inhibited the growth of at least one of the test pathogens used in the study. Isolates that inhibited the growth of Candida albicans, Klebsiella sp. and Pseudomonas aeruginosa were catalase positive, facultatively anaerobic, Gram negative bacilli. Some isolates exhibited unstained inclusion bodies in their cytoplasm in Gram-stained smears. No isolate was able to inhibit the growth of Escherichia coli, Salmonella typhi and Staphylococcus aureus.