Effects of Vermicompost, Tithonia Green Manure and Urea on Quality of Swiss Chard (Beta Vulgaris L. Var. Cicla L.) in Kenya

Abstract

Swiss chard (Beta vulgaris L. var. cicla) is a popular vegetable because it is nutritious, robust, easy to grow. It requires regular applications of nitrogen, which causes accumulation of oxalates and nitrates within the plant. Oxalates and nitrates are known health hazards but the use of organic fertilizers have been shown to reduce their accumulation and to promote accumulation of beneficial phytochemicals. We therefore determined the effect vermicompost (VC), Tithonia diversifolia green manure (Tithonia) and urea on the quality of Swiss chard. The experiment was laid out in a Randomised Complete Block Design (RCBD) replicated three times with thirteen treatments. Leaf nutrient elements, TSS, polyohenols, Vitamin C and antioxidants were determined using standard procedures. Treatment effects were significant only for aluminum, phosphorus and calcium. The values were highest on VC 50 kg N ha-1 and Urea 50 kg N ha-1, Tithonia 50 kg N ha-1 + Urea 50 kg N ha-1, and VC 50 kg N ha-1, and VC 100 kg N ha-1 for aluminum, phosphorus and calcium, respectively. Lowest response was reported on Tithonia 50 kg N ha-1, control and Tithonia 50 kg N ha-1 + Urea 50 kg N ha-1 for aluminum, phosphorus and calcium, respectively. The treatments significantly influenced the percentage of polyphenols, vitamin C and the antioxidant capacity while no significance was reported for total soluble solutes. The polyphenols and vitamin C content were highest on Tithonia 100 kg N ha-1 and control, respectively. Low polyphenol and vitamin C contents were recorded on VC 50 kg N ha-1 and VC 100 kg N ha-1, respectively. A similar trend was observed for antioxidant activity since a positive correlation was observed between the polyphenols and vitamin C and the antioxidant activity. Tithonia green manure improves Swiss chard quality.

Growth and yield response of Swiss chard (Beta vulgaris (L.) to media mixture ratios of sand, acacia soil, and goat manure

“…Swiss chard (Beta vulgaris L.) incorrectly referred to as Spinach [1] is a biennial leafy vegetable belonging to Chenopodiaceous family [2,3,4] which has been cultivated in Europe for thousands of years, with its extensive cultivation in Switzerland earning it the name "Swiss chard" [5]. The leaves are often used in salads because of its attractive flavor and delicate texture [6].…”

“…The leaves are often used in salads because of its attractive flavor and delicate texture [6]. The stalks are eaten because they are tender and rich in fiber [4,7]. Swiss chard can grow in any soil if it's well-drained, contains organic manure [8], with temperature ranging from 7-24 °C, its half hardy, and can stand light frost conditions.…”