Effect of Organic (Jatropha Cake) and NPK Fertilizers on Improving Biochemical Components and Antioxidant Properties of Five Cowpea (Vigna unguiculata L. Walp.) Genotypes

Organic and inorganic fertilizers improve the nutritional quality of crop. An experiment in pots of four treatments was conducted in a randomized complete block design in order to evaluate the effect of the application of organic and NPK fertilizers on the biochemical components and antioxidant activities of five cowpea genotypes. Results showed that organic fertilizer and the mixture of organic and NPK fertilizer have significantly (p < 0.05) increased the growth parameters and leaves quality traits of cowpea. The response of cowpea under the different treatment is also function of genotype type. The PCA and the dendrogram performed basis on the different fertilizers effect on growth parameters and leaves quality trait divided the treatments into three main classes. Class I comprising NPK + Jatropha treatment strongly contributed to lycopene, β-carotene and total chlorophyll contents, height and number of branches. Class II comprising NPK treatment solely and Jatropha treatment solely are highly linked to the variables FRAP, DPPH and protein content. Class III comprising control treatment strongly contributed to salicylic, soluble sugar, phenolics and flavonoids contents, and trypsin inhibition activity. The Jatropha cake could be used solely or in mixture with NPK to improve growth and the quality traits of cowpea leaves.