Open Access Original Research Article

Total Phenolic Compounds Extraction in Leaves of Ocimum gratissimum L. and Their Potential Activity against Some Agricultural Contaminants

Kporou Kouassi Elisée, Adela Pintea, Okou Obou Constantin, Antonia Odagiu, N’guessan Jean David, Djaman Allico Joseph

Asian Research Journal of Agriculture, Page 1-10
DOI: 10.9734/arja/2020/v13i430108

Aims: Phenolic compounds are secondary metabolites that are important in the plant due to their role in plant defense and their antioxidant activity with other biological properties such as antipyretic, analgesic and antimicrobial activities. This study focused on the biological potential activity of total phenolic compounds extracted by soxhlet method from Ocimum gratissimum leaves (Lamiaceae), a popular medicinal plant harvested at Daloa (Côte d’Ivoire).

Study Design: Activities were directed on the in vitro antifungal and antioxidant activities combined to phenolic compounds analysis.

Place and Duration of Study: The study was carried out at the Department of Environment and Plant Protection, and Laboratory of Chemistry and Biochemistry, University of Agricultural Sciences and Veterinary Medicine (USAMV) between March to July 2014, Laboratory of Biochemistry and Microbiology (Bioactives Natural Substances Unit), Jean Lorougnon Guédé University between September 2014 to January 2015.

Methodology: The extract obtained named TPCOG was tested against Fusarium species for its antifungal activity by applying agar slant double dilution method and for its antioxidant activity by DPPH radical scavenging assay. Qualitative and quantitative evaluation of phenolic compounds were carried out by HPLC analysis method with sigma chemical standards.

Results: Tests showed that TPCOG was a powerful antifungal extract with MIC and MFC ranging between 3.125 µg/mL to 12.5 µg/mL. This extract was fungicidal and its antioxidant activity reached F= 541.25± .25 mM Trolox/mL (I= 70 ±1.85%) with a total phenolic content equal 195.70±1.33 mg GAE/g. Radical scavenge and antifungal activities correlated very well with total phenolic compounds. Phenolic content analysis showed presence of phenolic acids and flavonoids with a higher concentration for Quercetin (393.475 mg/100 g sample).

Conclusion: All this results demonstrated the biological potential activity of total phenolic compounds extracted from leaves of O. gratissimum and the possibility to use it in replace to essential oil for the formulation of biofungicides and nutraceuticals by industries.

Open Access Original Research Article

Socio-Demography, Pesticides Use, and Health Status of Rice Farmers in Region XII, Mindanao, Philippines

Mitos D. Delco

Asian Research Journal of Agriculture, Page 11-23
DOI: 10.9734/arja/2020/v13i430109

The socio-demographic characteristics, pesticides use and health status of 300 rice farmers from Region 12 in the Philippines in 2015 were assessed. Likewise, the influence of the socio-demographic characteristics on the farmers’ pesticides use and health status was determined. This was done to describe the current well-being of farmers as basis for recommending strategies to improve their farming practices and health condition. Farmers were middle adults (60.6%), married (83.7%), had secondary education (50.7%), with household size of 1-4 members (62.7%), mostly non-owners (63.3%) of less than 3 hectares of land (91.7%), with total annual income of less than P101,000.00 (69.3%), nearly one third had more than 11 years farming and pesticides application experience and had availed at least one training on rice production for the last five years. Nearly 75% had health insurance. The socio-demographic characteristics did not influence significantly the pesticides use as to frequency and quantity of application and health status of the farmers. Age, however, is found a significant predictor of pesticides use as to frequency of application while civil status and farm ownership are the significant predictors of gaining normal health status as to Body Mass Index (BMI). Based on the findings, farmers still need more trainings on proper pesticides use and other farm technology options to keep their health protected and earn better profits from farming.

Open Access Original Research Article

Effect of Mineral Mix and Concentrate Feeds on Milk Revenue of Smallholder Dairy Farmers in Kapseret Sub County, Kenya

J. K. Bett, S. W. Munyiri, I. M. Nkari

Asian Research Journal of Agriculture, Page 24-34
DOI: 10.9734/arja/2020/v13i430110

Dairy farming contributes about eight percent of National Gross Domestic Product with an annual milk production of 3.43 billion litres in Kenya. It supports the livelihood of approximately four million Kenyans through food provision, income generation and employment. However, milk production per individual animal in Kenya, averaging six to seven (6-7) litres/cow/day, is low compared to the world’s best at 10,133 litres/cow/year (28 litres/cow/day) mainly due to factors including poor feeding. This means that Kenya produces an average of 20 litres of milk less per cow per day compared to the world’s best. The objective of this study was to determine the effect of mineral mix and concentrate feeds on milk revenue of smallholder dairy farmers in Kapseret sub County. The study was conducted between the months of January-March, 2020. Primary data was collected using closed and open ended questionnaires. Spearman’s Rank correlation was used to show the strength of the relationship between the variables. Multiple regression model was employed to assess the effect of supplementation on milk revenue. Results were presented in tables, and descriptive statistics such as percentages and frequencies. The results indicated a positive and statistically significant relationship between the variables (concentrate feeds and mineral mix) and milk revenue at (r=0.41, p=0.001) and (r=0.30, p=0.001), respectively. The relationship between mineral mix and concentrate feeds was positive and statistically significant (r=0.92, p=0.001). Subsequent feeding of homemade or commercial concentrates and mineral mix to dairy animals influenced milk revenue. The study concluded that mineral mix and concentrate feeds increased milk revenue of smallholder dairy farmers in Kapseret sub County. The study recommended the use of mineral mix and commercial concentrates or quality homemade concentrates in order to increase milk produce which affects farmers’ milk revenue.

Open Access Original Research Article

Evaluation of Saturated Hydraulic Characteristics and its Influence on Some Physical and Chemical Properties of Soils Developed on Coastal Plain Sands of Obufa Esuk Orok in Calabar, Cross River State, Nigeria

E. A. Akpa, A. I. Akpama, O. Oyedele

Asian Research Journal of Agriculture, Page 35-45
DOI: 10.9734/arja/2020/v13i430111

The study highlights the evaluation of saturated hydraulic characteristics and its influence on some physical and chemical properties of soils developed on coastal plain sands of Obufa Esuk Orok in Calabar, Cross River State, Nigeria. Sixteen grids designed in an experimental plot measured 6 m x 6 m were used for field studies and sixteen (16) soil samples were collected in each of the grid using a soil auger for particle size analysis, bulk density, particle density, total porosity and saturated hydraulic conductivity. The samples were analyzed using standard laboratory procedures. The result showed that the soils were predominantly high in sand content with a mean value of 860.6 g kg-1 and low in silt and clay contents with mean values of 56.1 g kg-1 and 83.3 g kg-1 respectively. The soil texture was predominantly loamy sand. The saturated hydraulic conductivity showed rapid with a mean value of 36 cm min-1. Total porosity was high, a mean value of 52.4 %. Bulk density was low, a mean value of 1.21 Mgm-3 while Particle density was moderate, mean value of 2.55 Mgm-3.  The soil pH showed very strongly acid milieu (mean pH in water = 5.1). Organic carbon and Total nitrogen were low with mean values of 1.1 % and 0.09 % respectively. Available phosphorus was high with a mean value of 36.66 mg kg-1. The exchangeable acidity and exchangeable bases were generally low with mean values of 2.54, 0.59, 0.08 and 0.053 cmolc/kg for calcium, magnesium, potassium and sodium and 0.261and 0.416 cmolc/kg for aluminum and hydrogen. The correlation coefficient (r) between the saturated hydraulic conductivity and texture showed that there was a positive relationship between saturated hydraulic conductivity and sand, silt and clay (correlation coefficient of r = 0.0013, 0.062 and 0.119) at p≤0.05 indicating good relationship. There was also a positive linear relationship between the saturated hydraulic conductivity and bulk density, particle density and total porosity (correlation coefficient values of r = 0.224, 0.03 and 0.107) at p≤0.05 respectively. Despite the positive relationship existed in their correlation, cultural practices such as minimum, zero, mulch tillage and other conservational practices should be adopted to help maintain the rapid condition of the saturated hydraulic conductivity to avoid restriction of water movement and other soluble nutrients in the soil.

Open Access Original Research Article

Effect of Exogenous Hormonal Stimulation on the Metabolic Partition between Plant Growth and Rubber Production of Hevea brasiliensis Clones According to the Class of Metabolic Activity in Cote d'ivoire

Lehi Malidy Irénée, Konan Djezou, Okoma Koffi Mathurin, Yoboue Ange Naté, Konan Kouakou Séraphin, Zouzou Michel, Obouayeba Samuel

Asian Research Journal of Agriculture, Page 46-64
DOI: 10.9734/arja/2020/v13i430112

Aims: In order to achieve a good and sustainable harvest of Hevea brasiliensis rubber, the effect of exogenous hormonal stimulation on the metabolic partition growth-production of clones according to the class of metabolic activity was made.

Place and Duration of Study: The study was conducted for 9 years in the San-Pedro region in south-west Ivory Coast, precisely in the experimental industrial plantations of the former HEVEGO, now Southwestern Agricultural Civil Society Société (SCASO).

Methodology and Results: The rubber trees were planted at a density of 510 trees/ha in a completely randomised system. They were bled in S/2 d4 and stimulated to 2.5% Etephon at annual frequencies of 0, 1, 2, 4, 6, 8, 13, 18, 26, 39 and 78. The parameters measured were rubber production, trunk circumference, sucrose content, inorganic phosphorus, thiol groups and dry notch rate. The results showed that productivity increased with the intensity of stimulation (58.96 - 68.49 g.a-1.s-1 ; 39.83 - 66.69 g.a-1.s-1) over the intervals [0.6] and [0.26] stimulations respectively in clones with active and slow metabolism. The circumference of the trunk was marked by a less pronounced decrease in growth in slow metabolizing clones (0.52%) with good protection of the laticigene system (R-SH : 0.815 mmol.l-1) and low sensitivity to dry notching (1.6). Whatever the classes of metabolic activity of the clones, the agrophysiological parameters were strongly correlated with each other by a degree 2 polynomial function.

Conclusion: This polynomial function seems to reflect the existence of a good state of equilibrium between laticigenic metabolism and vegetative growth according to the class of metabolic activity of the Hevea brasiliensis clones.