Effect of Phosphorus Deficiency on Phenolics and Antioxidants Content of Two African Nightshade Varieties Grown in Kenya
Journal Title: International Journal of Plant & Soil Science - Year 2017, Vol 15, Issue 3
Abstract
Indigenous vegetables form an integral part of the Kenyan diets, most commonly consumed being the African nightshade. These vegetables contain important phenolics and antioxidants that have medicinal and good health attributes. Their production has strongly been associated with environmental stresses, and phosphorus as one the limiting nutrients had been suspected to play key role. To investigate the effect of phosphorus stress on Total Phenolic Content (TPC) and Total Antioxidants Activity (TAA) on nightshade, greenhouse and field experiments were conducted. Two commonly grown varieties (Solanum villosum-SV and Solanum scabrum-SS) were planted in both conditions; done under long (May-July 2014) and short rain seasons (August-October 2014). It was laid as Randomized Complete Block Design with split plot arrangement. The two varieties were the main plot and phosphorus levels (0, 20, 40 and 60 kg/ha) constituted the subplot with four replicates. Gallic Acid (standard) Extraction method was used to analysis TPC. Diphenyl picryl hydrazyl method was used to analyze TAA where Vitamin C was standard. Data on TPC and TAA were recorded and later the effects resulting from these treatments analyzed using ANOVA and mean separation using Least Significant Difference (LSD) at p≤0.05. The TPC and TAA were significantly affected by different phosphorus levels (p≤0.05). TPC and TAA decreased with increase in phosphorus. SV had higher TPC and TAA (6.09 mg/g and 38.58% respectively) as compared to SS that had 5.49 mg/g (TPC) and 35.92% (TAA). SV had more phenolics and antioxidants in the shoots than roots, the converse was found for SS. Both varieties at 40 kgP/ha offered the best tradeoff between yield and secondary metabolites (phenolics and antioxidants). Study recommends 40 kgP/ha as it had the highest levels of phenolics and antioxidants. Further research needs to be done on other important antioxidants like anthraquinones and how different levels of macronutrients affect their production.
Authors and Affiliations
Ogembo Oyaro Joel, P. Nawiri, W. Musila, Joseph P. Gweyi-Onyango
Effect of Aluminum Toxicity on Root Growth and Morphology of Common Bean (Phaseolus vulgaris L.) Genotypes
Aims: To investigate the effect of aluminium on root growth, morphology and the concentration of aluminium in the root tissues of two common bean genotypes(new BILFA 58 and Roba 1) varying in soil acidity tolerance. Stud...
The Role of Organic Matter in Conservation and Restoration of Soils in Southeastern Nigeria: A Review
The threat and subsequent destruction of land by soil erosion and other land degradation agent has been the subject for intensive debate. The main focus of the paper is providing a critical scientific review of the curre...
Response of Sulphur Nutrition and Mulching on Indian mustard (Brassica napes L.)
Field experiment was conducted to study the effect of sulphur nutrition and mulching on Indian mustard (Brassica napes L.) at Rajeev Gandhi South Campus (Banaras Hindu University), Mirzapur, Uttar Pradesh during rainy se...
Sulphur and Zinc Fertilization Effects on Growth and Yield Response of Rice
Information on critical concentration and optimum rates of fertilizers is very important in the correction of sulphur (S) and zinc (Zn) deficiencies. A study was carried in the screen house experiments to establish optim...
Tomato Responses to Bioregulators Grown under Greenhouse Conditions
Aims: Greenhouse contemporaneous horticulture demands a permanent use of new technologies directed to improve yield and fruit quality. Although, the use of bioregulators has made an important contribution to agriculture...