Monthly Archives: October 2021

Reformulation of organic vermicast fertilizer and its performance in corn (Zea mays L.) at the early stage of growth

Authors: Mark Anthony M. Barbadillo1, Renante G. Macapanas2 and Romel B. Armecin2,3

ABSTRACT

The increasing demand for healthy and sustainable food production practices has encouraged farmers to switch to the use of organic fertilizers. Information on the nutrient composition of the available organic products is minimal. Hence this study was conducted to survey and collect samples of mudpress-based vermicast fertilizer materials in Western Visayas and do reformulation work to improve the nutrient composition and perform efficacy trials for corn seedling at the early stage of growth. Among the collected samples, soil pH values ranged from 4.7-7.0, OM from 25.40-45.40%, and total N, P, K, Na, Ca and Mg contents ranged from 0.70-1.40%, 0.04-0.90%, 0.30-1.00%, 0.03-0.17%, 1.30-2.60%, and 0.50-0.80%, respectively. Reformulated vermicasts contained high total N content (1.23-1.37%) but had lower total P, K, Na, Ca and Mg contents than most vermicasts from Western Visayas. The plant height, leaf area and dry matter yield of the corn seedlings using the reformulated vermicast was significantly higher than those seedlings treated with inorganic fertilizer.

Keywords: organic fertilizer, corn, dry matter yield, reformulation, vermicast


Isolation, characterization and antibacterial activity of actinomycetes from soils of the Langun-Gobingob Cave Complex in Calbiga, Samar

Authors: Jeffrae Isaac Albert R. Damayo and Rolly G. Fuentes*

ABSTRACT

The discovery of rare Actinomycetes from unexplored areas has proven to be a promising source of new antimicrobials. The Langun-Gobingob cave complex in Calbiga, Samar, Philippines is the second largest cave complex in Asia, yet this is the first reported search for actinomycetes conducted in the area. The main objective of this study was to assess the antibacterial activities of culturable actinomycetes from soil samples from the Langun-Gobingob cave complex. Five actinomycete colonies were isolated in pure culture from soil samples using Starch-Casein Agar medium. The isolates were identified by their morphological characteristics and they were characterized by 16S rRNA sequencing. The sequences were matched to sequences uploaded to the NCBI Basic Local Alignment Search Tool (BLAST). Four of the isolates belonged to the Genus Streptomyces and one belonged to the Genus Nocardia. The antibacterial potential of the isolates was tested against gram-positive and gram-negative test bacteria. One Streptomyces isolate exhibited antibacterial activity against the two gram-positive test bacteria. The limited cave area sampled in this study leaves the cave complex mostly unexplored in the search for antibacterial secondary metabolites.

Keywords: Actinomycetes, 16s rRNA, starch-casein agar, BLAST


Phosphorus forms and distributions in soils under selected land use practices at the Federal University of Agriculture, Abeokuta, Ogun State, Nigeria

Authors: Oladoye AO, Busari MA, Abiodun FO, Ojekunle OO, Oyebamiji NA and Olaife BA

ABSTRACT

The forms and distributions of phosphorus were determined for four different land use practices in Federal University of Agriculture, Abeokuta, with the aim of evaluating the effects of land use and soil depth on soil physical and chemical properties, forms and distributions of phosphorus. The study was a 4×2 factorial experiment laid out in a Randomized Complete Block Design. Factor 1 was four different land use practices (Gmelina arborea, Tectona grandis, Leucaena leucocephala plantations and secondary forest), and Factor 2 was soil samples collected from two soil depths (0-30cm and 30-60cm). The soil pH, electrical conductivity, exchangeable bases (Na, K, Mg and Ca), particle size, organic carbon, total nitrogen, total phosphorus, inorganic phosphorus fractions (Al-P, Fe-P and Al-P) and available phosphorus analyses were carried out using standard procedures. Data collected from the laboratory analysis were subjected to two-way Analysis of Variance while the means among the treatments were separated using Duncan Multiple Range Test. The results showed that the soils had low total and available P contents. The soil under Leucaena leucocephala plantation had the highest total phosphorus (111.05mg kg-1), followed by Tectona grandis (97.63mgn kg-1), Gmelina arborea (96.41mg kg-1) and secondary forest (83.63mg kg-1). Total P decreased with depths (0-30cm and 30-60cm). Inorganic P-fractions were greatly influenced by soil properties such as soil pH, soil electrical conductivity, organic carbon, and soil particle size. The inorganic phosphorus fractions of the soils in all study area occurred generally in the following sequential order; Fe-P>Ca-P>Al-P. The highest inorganic phosphorus recorded in all in the study area was Fe-P, followed by Ca-P and Al-P. Al-P had the lowest content between the depths examined. Lower nutrient concentrations in soils under secondary forest within the depths were due to lower organic matter content, higher nutrient demand, nutrient immobilization by tree species and other flora present. P fractionation investigations are therefore recommended in soils under indigenous species plantation in order to provide adequate understanding of P status in the soils and fertilizer recommendation so as to improve productivity.

Keywords: Land Use, Soil, Phosphorus, Inorganic fractions and Distribution


Degree of damage and infestation of coconut leaf beetle Brontispa longissima (Gestro) on seedlings of selected coconut varieties

Authors: Gladys R. Cabelin and Maria Juliet C. Ceniza

ABSTRACT

The Coconut Leaf Beetle, scientifically known as Brontispa longissima (Gestro), is an introduced species that is becoming an alarming pest of coconuts in the Philippines. The infestation caused by this pest is damaging to all stages of coconut growth. This study was conducted to assess the degree of damage and infestation caused by Brontispa longissima on the seedlings of 10 selected tall and dwarf coconut varieties in the National Coconut Research Center at Visayas State University, Leyte, Philippines. Among the selected varieties, seedlings of Baybay Tall (green and brown) and Albuera Dwarf varieties succumbed to more damage by B. longissima beetles compared with the other varieties observed with 41-80% of the first openned leaf area damaged. Seedlings of Malayan Yellow Dwarf and Malayan Red Dwarf varieties had the least damage with 0-20% of the first openned leaf area damaged. The high damage ratings of Baybay Tall and Albuera Dwarf were expected because these varieties had high infestation rates and harbored the most numbers of B. longissima adults, eggs, and larval stages, which indicated the preference of B. longissima for these varieties. The developmental period of B. longissima in Baybay Tall and Albuera Dwarf of 44 days and 45 days on the average, respectively, was shorter than in other varieties, indicating that these are suitable and preferred hosts. Baybay Tall seemed to be the most preferred variety. The beetles had least preference for Malayan Yellow Dwarf and Malayan Red Dwarf varieties.

Keywords: B. longissima, coconut varieties, BAYT variety, preference


Mycofumigation with the endophytic fungi Fusarium proliferatum (Matsushima) Nirenberg and Diaporthe sp. for the control of banana and mango anthracnose

Authors: Rochelle B. Cagadas*, Flor A. Ceballo1, Christina Joseph R. Cumagun1 and Ireneo B. Pangga2

ABSTRACT

Banana and mango are the top commodities in the Philippines that are traded worldwide however, fungal diseases such as anthracnose affect their yield and quality. Environmentally sound control strategies have been explored and one of these is mycofumigation using fungal endophytes. This alternative approach is understudied in the Philippines, hence, the study aimed to evaluate the mycofumigation potential of fungal endophytes collected from Mt. Makiling, Luzon, Philippines and their pathogenicity to banana and mango fruits. In vitro and in vivo mycofumigation assays were conducted with a completely randomized design layout with triplicates per treatment under laboratory conditions.

The fungal endophytes used as mycofumigants, Diaporthe sp. and Fusarium proliferatum, were comparatively effective in controlling the anthracnose of banana and mango. The mycelial growth for in vitro assay of Colletotrichum musae and Colletotrichum gloeosporioides were significantly reduced compared to the control when exposed to volatile organic compounds produced by the fungal endophytes. In addition, the results of the in vivo mycofumigation assay against C. musae showed Diaporthe sp. had a significantly higher inhibition rate (93%) than F. proliferatum (67%) when grown on potato dextrose agar plates.
The bioefficacy of the Diaporthe sp. and F. proliferatum was improved when grown on peanut and corn seed substrates with a reduction of banana and mango anthracnose severity ranging from 82 to 100%. Cultures grown on corn substrate performed better than those grown on peanut. Pathogenicity tests also revealed that these endophytic fungi did not cause disease in the banana or mango fruits indicating their potential as good biocontrol agents against C. musae and C. gloeosporioides.

Keywords: Mycofumigation, endophytic fungi, Diaporthe sp., Fusarium proliferatum, Colletotrichum musae, Colletotrichum gloeosporioides


The effects of calcium fertilizer on anthracnose and Rhizopus tuber rot of yam

Authors: Osijo Adedeji Taiwo1*, Otusanya Marian Olugbemileke1, Afolabi Clement Gboyega1 and Olowokere Florence Alaba1

ABSTRACT

Yam (Dioscorea spp) production is beset in the field and in storage by major fungal pathogens, namely Colletotrichum gloeosporioides that causes anthracnose in the field, and Rhizopus stolonifer that causes tuber rot in storage. Alternative control measures are imperative as conventional control of these pathogens is either ineffective or detrimental. This study investigated the effects of calcium fertilizer on the incidence and severity of anthracnose and Rhizopus rot of yam. Calcium nitrate fertilizer was applied to soils naturally infected with C. gloeosporioides, at the rates of 0, 3, and 4kg ha-1. D. rotundata variety Efuru was planted. The treatments were arranged in a randomized complete block design with three replicates. Anthracnose disease rating relied on natural endemic infection in the field, while inoculation of harvested yam tubers was carried out using R. stolonifer. There was no significant effect of calcium amendment of the soil on anthracnose severity in D. rotundata or on the agronomic parameters. D. rotundata tubers treated with 3 and 4kg ha-1 calcium soil amendments had reduced infection by R. stolonifer in storage compared to the control treatments. The study concluded that calcium applied to the soil had reduced storage losses by R. stolonifer in D. rotundata but had no influence on anthracnose severity in the field. Therefore, 3kg ha-1 of calcium nitrate applied to the soil can be used to improve D. rotundata tuber resistance to R. stolonifer, and is recommended for high-quality tuber storage.

Keywords: calcium nitrate, soil amendment, anthracnose, Rhizopus stolonifer, Dioscorea rotundata


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