Monthly Archives: July 2022

The effects of different tillage practices on soil properties, yield and pest incidence of various Sweet Corn (Zea Mays L. Var. Saccharata) varieties

Authors: Angela R. Escototo1 and Ulysses A. Cagasan1*


Conservation tillage is one of the crop production adaptation strategies for conserving soil and mitigating climate change. This study aimed to evaluate the effects of different tillage practices on the yield, soil properties, and pest incidence of corn varieties that would give optimum output. The experiment was laid out in a split-plot arranged in a randomized complete block design with three replications. Zero and minimum tillage served as the main plot, and the different sweet corn varieties as the subplot (T1– Macho F1, T2– Sweet Supreme F1, T3– Purple Magic F1, T4– Hi-Brix XL F1, and T5– Sugar King F1). Results showed that Hi-Brix XL F1 (8t ha-1), Purple Magic F1 (7.44t ha-1), and Macho F1 (7.45t ha-1) obtained high marketable ear yields among the different sweet corn varieties. On the other hand, zero and minimum tillage did not vary significantly in terms of the soil properties, resulting in no yield advantage for sweet corn. This means that sweet corn production can be done either with zero or minimum tillage. In addition, zero tillage practice obtained lower fresh weight (g) of weeds at 15 and 45 days after planting. Weeds were eliminated using non-selective herbicide spray with zero tillage, resulting in lower weed incidence than with minimum tillage where only one plowing and harrowing were done.

Keywords: Conservation tillage, sweet corn varieties, and yield performance

Annals of Tropical Research 44(1):86-98(2022)
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Candida albicans in backyard chicken flocks raised in a small community in Leyte, Philippines: Prevalence and risk factors associated

Authors: Kenny Oriel A. Olana*, Ana Marquiza M. Quilicotand Eugene B. Lañada


This study aimed to determine the prevalence of Candida albicans in backyard chickens flocks among small hold raisers in selected villages of Baybay City, Leyte and to identify the risks factors associated with the prevalence of C. albicans. Using Sabouraud’s dextrose agar, 185 (68.5%) out of 270 samples were positive with yeast and 94 (34.81%) out of those yeast isolates were positive for C. albicans. Multivariable logistic regression analysis results show unconditional association between the sex of the chicken with the isolation of C. albicans. The odds of roosters harboring C. albicans is 56% lower than hens (OR=0.44, 95% CI 0.2-0.7) with a p-value of 0.0047. Considering the possibility of contact between smallholder chicken flocks and the community, the isolation of C. albicans from apparently healthy chickens necessitates the implementation of proper hygiene and sanitation management especially in small-hold chicken flocks.

Keywords: candidiasis, fungal zoonosis, chicken, poultry candidiasis

Efficacy of Trichoderma harzianum against Fusarium oxysporum and Rhizoctonia solani on bean and tomato plants

Authors: Gwendolyn Ban1*, Shamsul Akanda2 and Macquin Maino3


Experiments were conducted in the laboratory, greenhouse, and field at the Papua New Guinea University of Technology (PNGUT) to assess the efficacy of Trichoderma harzianum against Rhizoctonia solani and Fusarium oxysporum. The dual culture of T. harzianum with R. solani and F. oxysporum isolated from the diseased bean and tomato plants under laboratory conditions showed 60.1% and 63.3%, and 54.9% and 61.6% growth reduction for R. solani and F. oxysporum, respectively. In greenhouse fungal inoculation experiments, bean and tomato plants showed relative germination index ranging from 0.56 to 1, 0.83 to 1, and disease reduction ranging from 64.8 to 96.1, and 20.3 to 83.7%, respectively. Field experiments involved tests with T. harzianum against one pathogenic fungus or against a combination of both R. solani and F. oxysporum,, applied simultaneously as the pathogenic fungi or five days before application of pathogenic fungi. The results for bean and tomato plants showed relative germination index ranging from 0.42 to 0.94, and 0.63 to 0.94, and disease reduction recorded at 63.8 to 96.1%, and 11.3 to 63.9%, respectively. The outcomes of this study will form the basis for further investigation into the potential routine use of Trichoderma spp. as biological control agents against soil-borne pathogens in PNG.

Keywords: Trichoderma, R. solani, F. oxysporum, biological control

Annals of Tropical Research 44(1):30-45(2022)
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Influence of potassium fertilization on the functional components and antioxidant activity of pummelo [Citrus maxima (Burm. Ex Rumph.) Merr.] fruit

Authors: Alminda Magbalot-Fernandez1*and Constancio C. De Guzman2


This study aimed to determine the influence of potassium (K) fertilization on the functional components and antioxidant activity of 13-year-old ‘Magallanes’ pummelo [Citrus maxima (Burm. Ex Rumph.) Merr.]. The field experiment was conducted at South Davao Corporation (SODACO) farm, Davao City for 12-month duration. Five treatments with increasing K levels were applied per tree: control, no K, 150g K basal, 225g K basal, and 225g K basal + foliar application. The functional components and antioxidant activity were analyzed following harvest at the University of the Philippines, Los Baños.

Application of 225g K rates positively influenced functional components of pummelo. The yield of total phenol, flavonoid, vitamin C and oil per tree increased by 3-10 times with 225g K application.

The effects of basal alone and foliar + basal application of K were only significantly different from each other in terms of flavonoid yield per tree. On the other hand, the application of 225g K basal + foliar resulted to higher total phenol, vitamin C and oil yield per tree in pummelo, implying a higher mobilization of K in the leaves than K uptake by the roots. The results of the study indicated the important role of K in improving the functional components in ‘Magallanes’ pummelo.

Keywords: Functional Components, Antioxidant Activity, Pummelo, Potassium

Annals of Tropical Research 44(1):17-29(2022)
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