Volume 9, Issue 2

Effect of Drying Methods and Type of Packaging Materials on Phytochemical Content and Total Antioxidant Capacity of Five Medicinal Plants with Cosmetic Potential over Three Months Storage at Ambient Temperature
Original Research
Drying and storage are the most integral parts of the post-harvest practices of herbal materials. These practices directly influence the physical and chemical quality of the processed product. Therefore, the main objective of the present study was to analyze the effect of drying methods and packaging materials on total flavonoid content, total phenolic content, and total antioxidant capacity of five medicinal plant leaves with cosmetic potential. Leaves of Hibiscus rosa-sinensis L., Senna alata (L.) Roxb., Centella asiatica (L.) Urb., Ocimum tenuiflorum L. and Justicia adhatoda L. were dried to a constant weight using shade drier at 30-35°C, solar drier at 30-40°C and oven at 40°C. Thereafter, dried leaves were stored using three different packaging materials namely glass jars, polythene bags and gunny bags at ambient temperature for three months. Aluminum chloride colorimetric assay, folin-ciocalteau method, and phosphomolybdate assay were employed to analyze the total flavonoid content (TFC), total phenolic content (TPC) and total antioxidant capacity (TAC) of ethanolic extracts of leaves respectively in each month. Data were presented as mean ± standard deviation of minimum three replications. Significant interactions of the drying methods and packaging materials on TAC, TFC and TPC of dried leaf materials were analyzed using Two-way ANOVA. Results showed that the maximum TFC, TPC and TAC in oven dried H. rosa-sinensis (23.48±2.49 mg RE/100g DW, 1.09±0.24 mg GAE/100g DW and 0.39±0.05 mg AAE/100g DW respectively) and C. asiatica (128.64±10.59 mg RE/100g DW, 2.38±0.32 mg GAE/100g DW and 2.2±0.05 mg AAE/100g DW respectively) leaves stored in glass jars and solar dried S. alata (117.43±9.00 mg RE/100g DW, 3.99±0.29 mg GAE/100g DW and 1.07±0.04 mg AAE/100g DW respectively), O. tenuiflorum (216.02±0.75 mg RE/100g DW, 1.92±0.12 mg GAE/100g DW and 1.07±0.03 mg AAE/100g DW respectively) and J. adhatoda (11.13±1.23 mg RE/100g DW, 1.02±0.19 mg GAE/100g DW and 0.42±0.04 mg AAE/100g DW respectively) leaves stored in glass jars at the end of the storage period. However, statistically significant interaction (p value < 0.05) was not reported between drying method and packaging material on TPC of C. asiatica and O. tenuiflorum leaves and TFC of S. alata leaves. In conclusion, determining the effect of different processing methods on chemical constituents of aforementioned plant leaf materials is suggested to assure the quality of the final product.
World Journal of Agricultural Research. 2021, 9(2), 73-79. DOI: 10.12691/wjar-9-2-5
Pub. Date: May 15, 2021
Towards Management of South Kivu Ferralsols by the Contribution of Different Types of Fertilizers: Their Influence on the Biofortified Climbing Bean Behaviour
Original Research
For many tropical and subtropical countries, poor soil fertility management is still a major problem in agricultural production and requires sustained attention. This study was carried out to evaluate the effect of the combination of fertilizer types on the improvement of ferralsol properties and on biofortified climbing bean yield in South Kivu. The experimental field was conducted by using a CRB plot with three replications. Ten treatments were followed consisted of a control, mineral fertilizer NPK (150 kgha-1), farmyard manure (30 tha-1), liming (1.3 tha-1), fresh biomass of Tithonia diversifolia (30 tha-1), and their combinations. The results obtained show significant differences between the treatments and their ability to improve the chemical properties (acidity, OM, N, and K) of the ferralsol during the two cropping seasons. This improvement has led to improvements significantly in the growth, yield, and profitability of climbing beans. The combination of farm manure and NPK (2.6 tha-1); liming-NPK and straw biomass of Tithonia sp. presented the same yield performance. With a profit margin of 900 and 850 USDha-1, Tithonia sp. could replace expensive mineral fertilizers. This study shows that liming coupled with low rates of fertilizer or Tithonia sp. on ferralsol in eastern RD Congo conditions and have the potential for improving the availability of soil nutrients and providing the quantities required nutrients needed for growing biofortified climbing beans and thus reduce malnutrition in the region subsequently fight against Fe and Zn micronutrient deficiency.
World Journal of Agricultural Research. 2021, 9(2), 65-72. DOI: 10.12691/wjar-9-2-4
Pub. Date: May 14, 2021
Soil Fertility Management Practices by Smallholder Farmers in the Bamboutos Mountain Ecosystem
Original Research
Low soil fertility is one of the major constraints faced by smallholder farmers in the Bamboutos Mountain ecosystem. A survey of 261 randomly selected smallholder farmers was conducted using a standard questionnaire to identify the major cropping systems used by smallholder farmers, the practices that smallholder farmers use to maintain or improve soil fertility, the types of manure or fertilizer used as well as the major crops grown in the area. An interview schedule was used to collect data and the descriptive statistics used for data analysis. Findings indicated the farmers practiced, inter cropping, crop rotation and agroforestry with intercropping being the most practiced cropping system. The farmers use both organic manures and inorganic fertilizers for crop production with the major organic manure being fowl dropping and the major inorganic fertilizer being N-P-K 20-10-10. To increase soil fertility, 73% of the farmers allow for fallow periods and the dominant vegetation during the fallow were: grasses, grasses +Tithonia and Grasses + shrubs. The major crops planted both organically and with inorganic fertilizers were Potato, cabbage, carrot, maize, beans, leeks and celery.
World Journal of Agricultural Research. 2021, 9(2), 58-64. DOI: 10.12691/wjar-9-2-3
Pub. Date: April 26, 2021
Sustainable Bamboo Farming to Mitigate Soil Degradation in Kinale Area, Kiambu County
Original Research
Increasing global attention towards the potentially devastating effects of climate change provides the need to focus on adoption of sustainable Bamboo farming to mitigate the effects of soil degradation. The objective of this study was to determine how sustainable Bamboo farming was adopted to mitigate the effects of soil degradation in Kinale area of Kiambu County. Data collection was done both quantitatively and qualitatively by use of questionnaires, focus group discussion and observations. Random sampling was used to select the interviewee of the study. Data was collected using questionnaire and focus group discussions, analyzed using SPSS versions 2.0 and results presented in percentages, frequency tables, charts. Pearson correlation with a significance of 0.05 was used to show relationship between the dependent and independent variables. The results of the study indicated that sustainable Bamboo farming was effective in curbing soil degradation with 93% of farmers stating it was reliable in averting the effects in their lands. The study recommended need for proper training to the farmers who are practicing on how to propagate Bamboo.
World Journal of Agricultural Research. 2021, 9(2), 53-57. DOI: 10.12691/wjar-9-2-2
Pub. Date: April 25, 2021
Efficacy of Trichoderma asperellum Seed Treatment and Ridomil® Application in Managing Late Blight on Potato
Original Research
Potato seed tubers latently infected with Phytophthora infestans initiate late blight that requires early fungicide application raising economic and human concerns. The objective of the study was to determine the efficacy of Trichoderma asperellum seed treatment and Ridomil® (Metalaxyl 4% and Mancozeb 64%) application to manage late blight. Ridomil® was applied at 21-, 14- and 7-day intervals on seed tuber and apical cuttings pre-treated with T. asperellum at 33 % (3 × 106), 66% (7 × 106) and 100% (1 × 107 CFU/mL) concentration by either dipping or injection. Results revealed that 7- and 14-day spray intervals were not significantly different (P=0.05) in terms of yield and late blight severity. Rooted apical cuttings had 7.4% higher disease severity resulting in 2.3% lower yield than crop from seed tubers. T. asperellum at 66% and 100% concentrations reduced disease severity by 26% and 27% respectively. Pericardial injection had 8.3% higher yield and conversely 7.8% higher disease severity than dipping. The combination of T. asperellum at 66% concentration with a 14-day spray interval provided better late blight management. The results suggest that seed treatment by dipping using 66% T. asperellum suspension could increase fungicide application interval by 7 days while improving on yield.
World Journal of Agricultural Research. 2021, 9(2), 42-52. DOI: 10.12691/wjar-9-2-1
Pub. Date: February 23, 2021