Category Archives: Volume 35 No. 1 (2013)

Increasing Cabbage Production Through NPK Application In Cabintan, Ormoc City, Leyte, Philippines

Authors: Anabella B. Tulin1, Roland V. Rallos1, Mechelle B. Rañises1 and Chris Dorahy2


One of the major issues affecting vegetable production in the Southern Philippines is the improper allocation of limited resources such as fertilizers due to lack of knowledge on the nutrient status of the soil. This study determined the effects of P application on P fertilizer efficiency and demonstrated the influence of N, P and K application in increasing the yield of cabbage (Brassica oleracea L.) in Cabintan, Ormoc City, Philippines. The treatments included: T1 – Farmers’practice consisting of chicken manure (75 bags/ha) + Complete (12 bags/ha) + Urea (13.5 bags/ha); T2 – Ammophos (5.5 bags/ha) + Muriate of Potash (1 bag/ha); T3 – Ammophos (11 bags/ha) + Muriate of Potash (2 bags/ha); T4 – Ammophos (8.25 bags/ha) + Muriate of Potash (1.5 bags/ha). The study demonstrated the importance of applying appropriate levels of NPK fertilizers in improving the growth and yield of cabbage. It also revealed that reducing the fertilizer costs by 50 percent in Treatment 3 as compared to the farmer’s practice in Treatment 1 (i.e. from P38,400 to P16,800) would give a more sustainable yield as compared to the farmer’s practice. Reduction of fertilizer inputs from 444-93-142 kg/ha N-P2O5-K2O to 88-110-60 kg/ha N-P2O5-K2O in T3 will lead to a better allocation of limited resource that is available to the farmers.

Keywords: fertilizer cost, nutrient loading, nutrient balance, levels of NPK fertilizers, cabbage yield

Annals of Tropical Research 35(1):118-130(2013)
Full PDF

A Comparative Analysis of the Stomatal Density of Ficus septica Burm. f. Along an Altitudinal Gradient at the Kalungan Forest of Mt. Talinis, Bacong, Negros Oriental

Authors: Ma. Harriette C. Apostol, Kathleen Amor R. Berones, Marsha C. Coritico, Vallisandro C. Sabarillo, Maria Elisa B. Gerona, Jerome Benedict P. Cabansag


Altitude is one of the environmental factors that affects a number of plant developmental processes, including stomatal development. In this study, the nail polish imprinting method was used to determine if stomatal density increases with increasing elevation in Ficus septica Burm. f. a widely distributed woody species in the Kalungan Forest, Mt. Talinis, Bacong, Negros Oriental. Sampling was done from 392 – 894 m above sea level from three trees per elevation. Six elevation stations were identified at 100 m interval. Leaf stomatal imprints from three trees per elevation were obtained. Stomata were counted manually with the aid of software ImageJ 1.45. Stomatal density values of the highest and lowest elevation were 3869.6 ± 814.1 and 1125.6 ± 357.1, respectively. Regression analysis showed a strongly linear relationship between stomatal density and elevation.

Keywords: fig tree, elevation, stomata, Moraceae, Philippines

Annals of Tropical Research 35(1):105-117(2013)
Full PDF

Physico-chemical Changes in Tomato (Solanum lycopersicum L.) Fruits as Influenced by Cultivation Systems and Modified Atmosphere Packaging

Authors: Ness Marie Sta. Iglesia, Marcelo A. Quevedo and Zenaida C. Gonzaga


Tomatoes are highly perishable and postharvest losses vary greatly among production areas and seasons of production. This study was conducted to evaluate the effects of open or protected cultivation system and postharvest modified atmosphere packaging (MAP) on the physical and chemical changes of tomatoes during ambient storage with temperatures ranging from 20°C to 35°C and relative humidity (RH) of 80% to 90%.
The cultivation system had no significant effect on the physicochemical constituents. In contrast, MAP storage significantly influenced some of the storage parameters evaluated. Use of paper bags and 0.02 mm thick low density polyethylene bags with diffusion holes slightly delayed ripening, effectively reduced weight loss, minimized decay incidence and maintained better visual quality throughout the 12 – day storage period relative to fruits stored in the open.

Keywords: Tomato (Solanum lycopersicum L.), Modified Atmosphere Packaging (MAP), Cultivation systems, Physical parameters, Chemical parameters

Annals of Tropical Research 35(1):74-104(2013)
Full PDF

Performance of Growing Lambs as Influenced by Liquid Acid Whey Supplementation

Authors: Angie R. Poliquit and Serena L. Sanchez


Twelve male growing lambs were used in a randomized complete block design to determine the effects of feeding liquid acid whey (LAW) on the performance of the animal, its dry matter intake, nutrient digestibility, weight gain and ruminal pH. Animals received a diet consisting of Napier grass (Pennisetum purpureum, Schumacher). Treatments were Napier grass plus concentrate, Napier grass plus LAW and Napier grass plus concentrate plus LAW. Individual dry matter intake (DMI), biweekly weight gain (WG) and ruminal pH were measured. Diet digestibility was determined using the total collection method. Results showed that LAW increased (p<0.05) WG and diet digestibility (dry matter, organic matter and crude protein). Liquid acid whey had an average digestibility of 54.41% for dry matter, 83.94% for organic matter and 87.56% for crude protein. Ruminal pH two hours after feeding was stable for animals with LAW alone. However, DMI was similar (p>0.05) among treatments. It can be concluded that including LAW in the diet significantly improved WG, diet digestibility and ruminal pH without affecting DMI.

Keywords: lamb, acid whey, supplement, dry matter intake, ruminal pH, digestibility

Annals of Tropical Research 35(1):61-73(2013)
Full PDF

Morpho-Physical and Chemical Characteristics of Mountain Soils in Central Leyte

Authors: Deejay S. Maranguit and Victor B. Asio


An important prerequisite to sustainable soil management is a good understanding of soil morphological, physical and chemical characteristics. Until now, very limited data are available on the characteristics of mountain soils in the central part of Leyte Island. Thus, this study was conducted to determine the morpho-physical and chemical characteristics of mountain soils derived from andesite and shale in central Leyte, and to evaluate the effects of parent material and topographic position on the properties of the soils.
Eight soil profiles representing the dominant parent materials and topographic positions in the Abuyog-Mahaplag-Baybay portion of the central mountain range of the island were examined. Results revealed that the soils varied in their morphological, physical and chemical characteristics which to some extent reflect the nature of their parent material and the slope positions where they were formed. Soils derived from shale (Soil profiles 1, 2, 3 and 6) developed into young (Fluventric Eutropepts) and well-developed (Typic Hapludalfs) soils with generally moderate nutrient status. Soils derived from andesite (Soil profiles 4, 5, 7 and 8) developed into young (Typic Dystropepts) and well-developed (Typic Kandiudults) soils with generally low nutrient status. Regardless of parent material, soils on summit slope position tended to be better developed than soils on footslope and shoulder slope positions. The study showed that the influence of parent material on soil development was modified by the topographic position.

Keywords: volcanic soil, sedimentary soil, Leyte central highlands, soil characteristics

Annals of Tropical Research 35(1):35-60(2013)
Full PDF

Effects of Chitosan Isolated from Crab Exoskeleton on Postharvest Stem-end Rot Disease and on the Quality of Mango Fruit

Authors: Dewoowoogen P. Baclayon1 and Candelario L. Calibo2


Natural products for disease control and quality enhancement of fruit after harvest are increasingly used as alternative to chemical pesticides which are hazardous to human health and the environment. This study was conducted to extract chitosan from crab processing waste and compare its effect with commercial chitosan (Sigma) on stem-end rot disease and on the quality of carabao mango fruit. FT-IR spectra exhibited characteristic absorption bands of the amides, the amines and the carbonyl occurring as prominent and sharp peaks in both laboratory-produced and the commercial chitosan. In vitro assay of D. natalenses against chitosan showed comparable inhibitory effect on fungal growth and development with that of Dithane (‘mancozeb’). When the extracted and commercial chitosan were dissolved in 2% acetic acid and applied at 0-500 ppm, it was found that chitosan regardless of source and concentration can reduce weight loss in mango during storage. Dipping the fruits at different chitosan concentrations significantly reduced the infection rate of stem-end rot disease. The infection rate in fruits treated with 100 ppm laboratory-produced chitosan was comparable with that of 500 ppm Sigma chitosan. The results of this study suggest that the laboratory-produced chitosan at 100 ppm is comparable with that of Sigma chitosan as they significantly slowed down the infection rate of stem end rot disease caused by D. natalensis. Chitosan’s antimicrobial action and beneficial effects on fruit quality could have far reaching application in the fresh fruit industry.

Keywords: Biopesticide, chitosan, Colletotrichum gloeosporioides, Diplodia natalensis

Annals of Tropical Research 35(1):23-34(2013)
Full PDF

Jamaican Spices as Food Preservatives

Authors: Roy B. R. Porter1, Lawrence A. D. Williams2, Grace-Ann O. Junor1 and Cheryl Green2


The present review is a compilation of the spices commonly used in Jamaica for preserving foods especially meats. These include: Allium cepa L. (onion), Allium fistulosum L. (Escallion), Allium sativum L. (Garlic), Capsicum annum L. (Scoth bonnet), Capsicum frutescens L. (Bird pepper), Curcuma domestica Valeton (Turmeric), Cinnamomum zelanicum Nees (Cinnamon), Pimenta dioica (L.) Merr (Pimenta), Plectranthus amboinicus (Lour) Launert (French thyme), Rosmarinus officinalis L. (Rosemary), Thymus vulgaris L. (Thyme) and Zingiber officinale Roscoe (Ginger).

Keywords: Antioxidant, antimicrobial, oleoresin

Annals of Tropical Research 35(1):13-22(2013)
Full PDF

General Performance and Cocoon Yields of Two Hybrids of the Silkworm, Bombyx Mori L. (Lepidoptera: Bombicidae), Fed on Mulberry Leaves from Different Amended Soils

Authors: Isaac Baba tunde Alebiosu1,Ganiyu Olatunji Olatunde2 and Olufemi Olutoyin Richard Pitan3


The performance and cocoon yields of two silkworm hybrids – W1D2 and C1J2 – grown on mulberry leaves from NPK fertilizer-, poultry manure– or non-amended soils were investigated in a 2 x 3 factorial experiment fitted into a completely randomized design with four replicates. Mulberry leaves from the three treatment plots were randomly selected for proximate analysis. Cocoon yield was significantly higher in silkworm hybrid 1 W1D2, irrespective of soil amendments, compared to hybrid 2 C1J2. Number of cocoons, single cocoon weight and shell weight were significantly higher from amended soils compared with the control. Larval and pupal weights were not influenced significantly by silkworm hybrid, soil amendments or their interaction. Fecundity was significantly higher in silkworm fed with leaves amended with NPK compared to leaves from soil amended with manure, which was not significantly different from the control. Larval and adult emergence was not affected by the two amendment factors; however, mortality was significantly higher in the control. Nitrogen, phosphorus and calcium contents were positively correlated with number of cocoons, single cocoon weight, and shell weight. Mineral contents were significantly higher in poultry manure-grown leaves than in NPK-grown ones which was higher than the control. On the other hand, cocoon yield was significantly higher in the NPK-grown leaves. However, both soil amendment methods could be adopted for mulberry leaf production for silkworm rearing.

Keywords: Bombyx mori, NPK, manure, cocoon yield, developmental characteristics

Annals of Tropical Research 35(1):1-12(2013)
Full PDF