Category Archives: Volume 36 No. 1 (2014)

Detection of Copper (II) and Iron (III) in Aqueous Solutions Using the Spectroscopic Characteristics of Bugnay (Antidesma bunius) Anthocyanins

Authors: Jonathan M. Barcelo1, Jan Narlo Abril1, Khristine Mereille P. Castillo1, Alloisa Diaz1, Jonathan Paul Ladera1, Jaemie Javar1 and Elisha Labuguen2


The spectrophotometric characteristics of bugnay (Antidesma bunius) anthocyanins in acidified solutions of copper (Cu2+) and iron (Fe3+) were investigated after one hour of reaction to determine the changes in their absorbance characteristics. Anthocyanins from bugnay were isolated using solid phase extraction followed by evaporation at 40°C. The total anthocyanin content of the extract was determined to be 103.87 ± 2.91 mg/L cyanidin-3O-glucoside equivalents using pH differential method. Maximum absorbance readings at pH 1.0 and 4.5 were determined to be at 520 nm and 350 nm, respectively. Cyanidin-3-glucoside was identified as one of the components of the three pigments in the extract using reversed phase high performance liquid chromatography. At pH 1.0, copper caused greater hypochromic shift of bugnai anthocyanins compared to iron (p<0.01) while iron caused greater hypochromic shift at pH 4.5. Copper also caused hypsochromic shift of anthocyanins from 520nm to 350nm at pH 1.0 but not at pH 4.5. Correlation analysis showed a significant moderate positive correlation between mean % hypochromic shift and concentration of copper ions at pH 1.0 (R2 = 0.603, ρ<0.01) and 4.5 (R2 = 0.533, ρ<0.01), and iron at pH 4.5 (R2 = 0.638, ρ<0.01). The spectroscopic characteristics of bugnay anthocyanins at 350 nm and 520 nm can be used as parameters to detect copper and iron in acidic solutions.

Keywords: Anthocyanins, Antidesma bunius, Ancyanidin-3-O-glucoside, hypochromic shift, hypsochromic shift

Annals of Tropical Research 36(1):102-118(2014)
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Nutrient Analysis, Decomposition, and Nitrogen Mineralization of Various Organic Amendments Used for Pechay Production

Authors: Clea Anne E. Vallejera1, Anabella B. Tulin1,2, Victor B. Asio1 and Chris G. Dorahy3


Farmers are increasingly using alternative fertilizer inputs such as manures and composts due to the high cost of inorganic fertilizers. However, different organic amendments have varied characteristics and thus also their effects on soil properties and the growth and yield of crops. The study was conducted to determine the characteristics and nutrient content of organic amendments, evaluate the decomposition rate and nitrogen mineralization rate of the various organic amendments, and examine the effects of different organic amendments on pechay. Four organic amendments used include swine manure, chicken dung, mudpress, and vermicast. These were analyzed for total elemental analysis, microbial decomposition, and nitrogen mineralization rate. A pot experiment was carried out to test the effects of these amendments on the growth and yield of pechay. Results showed that organic amended soil significantly increased the rates of microbial decomposition and nitrogen mineralization, organic material content, and the growth and yield of pechay. In terms of total elemental analysis, chicken dung had the highest content of essential nutrients such as P, K, Ca, and Cl as compared to mudpress, vermicast, swine manure, hence, has good potential as source of organic fertilizer for vegetable production. High amounts of heavy metals such as lead, strontium, nickel, copper, and zinc were detected in the swine manure.

Keywords: amendments, total elemental analysis, nitrogen mineralization, pechay.

Annals of Tropical Research 36(1):88-101(2014)
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Sensitivity of Leaf Spot Causing Pathogen of Bitter Gourd (Cercospora citrullina Cooke) To Different Fungicides

Authors: Dindo King M. Donayre1 and Lucille T. Minguez2


Cercospora leaf spot disease caused by Cercospora citrullina Cooke is one of the most important diseases of bitter gourd. Effective fungicide against the causal pathogen has not been reported. This study was conducted at the Plant Pathology Laboratory of the Crop Protection Cluster, College of Agriculture, University of the Philippines Los Baños, College, Laguna to (a) determine the sensitivity of C. citrullina Cooke to different fungicides, and (b) determine the most effective fungicide against C. citrullina. Four fungicides, namely, benomyl (0.63 g a.i. L-1), chlorothalonil (1.41 g a.i. L-1), copper oxychloride (0.63 g a.i. L-1) and mancozeb (3 g a.i. L-1) were tested against the pathogen. Under laboratory condition, all conidia of C. citrullina did not germinate when treated with the test fungicides. Under screen house condition, the fungicides also effectively suppressed the development of the disease owing to low number and non-increasing of lesions in the leaves of bitter gourd. All test fungicides were very effective against leaf spot disease causing pathogen of bitter gourd.

Keywords: C. citrullina, Momordica charantia, leaf spot, benomyl, chlorothalonil, copper oxychloride, mancozeb

Annals of Tropical Research 36(1):75-87(2014)
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Effects of N Application on the Development of Blast Disease and Yield of Rice Under Sawah System in Nigeria

Authors: Clement G. Afolabi1* and Sunday O. Adigbo2


Rice blast, caused by the fungus Pyricularia grisea, is one of the limiting factors in rice production causing severe crop losses under favourable environmental conditions. The effects of nitrogen applications on leaf blast development and yield of rice were studied under sawah system of production. WITA-4 and Jasmine rice varieties were planted and four levels (0, 30, 60 and 90 kg ha-1) of urea fertilizer were imposed. Nitrogen and rice varieties treatments were arranged in a split plot design with N levels as main plots and varieties as subplots, with three replications. The results obtained indicate that Jasmine variety was not infected by the blast pathogen whereas WITA-4 variety was susceptible to the disease. Disease incidence was generally high on 0 and 90 kg ha-1 but there was no significant difference among treatments. However, there was a significant difference (P=0.0001) between the N treatments for final disease severity score and the total lesion area, with 90 kg ha-1 having the highest severity score and total lesion area. Significant differences between nitrogen treatment (P=0.001), varieties (P=0.01) and the nitrogen treatment x cultivar interactions (P=0.05) with respect to grain yield were observed. In terms of yield, Jasmine variety had 5.4 tons/ha on 90 kg ha-1 N treatment but the effect of the blast was pronounced on WITA-4 variety with 4.7 tons/ha. Rice cultivation under sawah system does not preclude rice from blast infection; hence, an appropriate management system must be incorporated to ensure bumper

Keywords: Rice, Leaf Blast, Nitrogen, Sawah, Yield, Nigeria

Annals of Tropical Research 36(1):63-74(2014)
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Extrapolating Bypass Protein Potential of Treated Soybean Meal by In Situ Degradation in Rumen-Fistulated Brahman Cattle

Authors: Angelo Francis F. Atole and Lolito C. Bestil


Loss of dietary proteins through microbial fermentation in the rumen may deprive the ruminant animals of valuable supply of amino acids at the intestinal level. This study was conducted to determine the effectiveness of three treatment methods (heat, formaldehyde, and tannic acid) in protecting dietary protein in soybean meal (SBM) from excessive microbial degradation in the rumen to extrapolate its bypass protein potential. The treated SBM samples were incubated for 24, 48, and 72 hr in rumen–fistulated cattle.
Results showed that the different treatment methods significantly reduced the rumen degradation of dry matter (DM) in SBM for 24-hr (p<0.01), 48-hr (p<0.01) and 72-hr (p<0.05) incubation, with tannic acid treatment showing the least. In terms of crude protein (CP) degradation,all the treatment methods showed significant reduction in 24-hr (p<0.01) while heat and formaldehyde in 48-hr (p<0.05) incubation, while tannic acid treatment did not differ significantly with that of the untreated, indicating their greater potential than tannic acid in protecting dietary protein from microbial degradation in the rumen. A similar pattern of differences were observed as that of actual values in terms of rates of DM and CP degradation. Overall, heat and formaldehyde treatments can effectively increase the potential of dietary protein to supply the needed amino acids in the intestines.

Keywords: Formaldehyde, heat, tannic acid, soybean meal, in situ degradation

Annals of Tropical Research 36(1):50-62(2014)
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Organic Versus Inorganic Management on the Yield and Soil Fertility of Irrigated Lowland Rice

Authors: Michelle C. Quimbo, Cezar P. Mamaril and Kathy Loren S. Tafere


Organic farming is being promoted by advocates to sustain and improve soil fertility compared to conventional farming that uses inorganic fertilizers and pesticides. The study was conducted to determine the effect of pesticide and fertilizer management practices on grain and straw yields, yield components, and soil fertility of irrigated lowland rice. The experiment was conducted for three consecutive seasons (2009-2010) at Los Baños, Laguna, Philippines. It was laid out in a Split Plot design consisting of two main plots: with pesticides (M1) and without pesticides (M2), and four subplots: control (T1), organic fertilizer only (T2), inorganic fertilizer only (T3), and one-half (½) rate of inorganic plus ½ rate of organic fertilizers (T4), with four replications. Generally, pesticide application did not affect the yield and yield components. Plots applied with inorganic and one-half rate of combined organic and inorganic fertilizers had significantly higher grain yields than the control and organic only fertilizer treatments. Application of limiting nutrients through inorganic fertilizers helps to correct most of soil deficiencies such as phosphorus and sulfur compared to the use of organic fertilizer alone. Combining organic materials such as compost and rice straw with inorganic fertilizers at one-half rates is an effective strategy to attain yields comparable to pure inorganic application to sustain soil fertility.

Keywords: conventional fertilization, organic fertilizers, inorganic fertilizers, pesticide application, soil fertility

Annals of Tropical Research 36(1):32-49(2014)
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Fruit Bronzing, a New Disease Affecting Jackfruit Caused by Pantoea stewartii (Smith) Mergaert et al.

Authors: Ruben M. Gapasin1, Garcia, R. P.2, Christine T. Advincula3, De la Cruz, C.S.2 and Lucia M. Borines1,4


Jackfruit bronzing, an unreported disease affecting jackfruit is characterized by yellowish-orange to reddish discoloration of the affected pulps and rags of the fruit. The etiology of this disease, its isolation, pathogenicity, characterization and identification is the scope of this study. The pathogen was isolated from infected jackfruit, pathogenicity was conducted to detached and attached fruits. The pathogen was identified based on its cultural and morphological characteristics, staining reactions, physiological and biochemical characteristics, other plant inoculations and DNA analysis using the polymerase chain reaction (PCR). The bacterium produces yellow pigment in culture, Gram negative, slightly pleomorphic non-motile, facultatively anaerobic short-rods, measuring 12 um in length, catalase positive, hydrolyzes gelatin and starch but not tween 80, produces acid from glucose, galactose, fructose and sucrose but not from lactose and maltose. It did not produce hypersensitivity to tobacco, caused pits on potato discs but not soft rot. It infected pineapple fruits causing localized lesions and infected corn producing the same symptom as bacterial wilt or Stewart’s disease. PCR analysis confirmed the cause as Pantoea stewartii (or Pantoea stewartii subsp. Stewartii (Smith) Mergaert et al)., formerly Erwinia stewartii (Smith) Dye.

Keywords: Bronzing, Jackfruit, Pantoea, Etiology, PCR

Annals of Tropical Research 36(1):17-31(2014)
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Prospects of the Components of Myanmar Food Control System for Health and Trade Efficacy

Authors: Wai Yee Lin1 and Masahiro Yamao2


Limited functional capacity and inadequate resources of government food control are common constraints in the export success of agricultural-resource-rich developing countries, thereby resulting to less competence in international food trade. The main sources of income for majority of the population depend on and directly relate with the success of primary food production and export. Thus, governments need to invest in food control system and other segments such as commodity standards formation, consistent quantity provision, and reliable inspection and laboratory services for trading system to be efficient. This paper presents SWOT factors identification of five key components of Myanmar food control system for tracing the process of food control works improved along with external pressures brought about by globalized food trade. Due to initial development stage of standardization activity, the technical regulation information gap between national standard body and trade promotion organizations in food trade was reported. The formation of National Quality Infrastructure has been in the process since 2012. Overall, there was a huge gap between food control governed by authority and food production industries. This paper stated nine strategies as recommendations. Law enforcement and the authorities’ role in controlling should have to be reexamined for health efficacy. With regard to consumer participation, active-surveillance information flow should been courage so as to crack down and prevent dishonest trading and counterfeit goods productions inside the community. Finally, there were many rooms left for development of the components of the food control system for health and trade efficacy.

Keywords: Food control, coordination, food safety, export success

Annals of Tropical Research 36(1):1-16(2014)
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