Development, Yield, and Antioxidant Content in Red Cabbage As Affected by Plant Density and Nitrogen Rate

ABSTRACT

Red Cabbages (Brassica spp.) are becoming popular as intact or fresh-cut products for consumers. Head size and yield are important quality parameters for marketing. These factors are influenced by N application and plant density, which can affect anthocyanin content, which is responsible for the red color and ascorbic acid content. The study was undertaken to determine the influence of nitrogen application rate and plant density on yield, head size, anthocyanin and ascorbic acid contents, and antioxidant activity in Red Cabbage (B. oleracea L. var. capitata f. rubra DC.), cv. Red Jewel. Cabbage plants were fertilized with 40, 80, 120, 160, or 200 kg∙ha⁻¹ N using NH₄NO₃ at plant densities of 100,000, 125,000, or 166,700 plants∙ha⁻¹, achieved by plant spacings of 20 × 25, 20 × 20, or 20 × 15 cm, respectively. Rates of N and plant density did not affect head size or yield. Anthocyanin and ascorbic acid content and antioxidant activity were higher at 80 kg∙ha⁻¹ N and at 125,000 plants∙ha⁻¹, which can be used without negatively affecting cabbage head size and yield.

KEYWORDS:

• Brassica oleracea var. capitate
• Agronomic practices
• Anthocyanin
• Ascorbic acid
• Head size
• Yield

Funding

Financial support by the South African Research Chairs Initiative (SARChI) programme (Phytochemical Food Network to Improve the Nutrition for the Consumers; Grant Number 98352) is greatly acknowledged.

Additional information

Funding

Financial support by the South African Research Chairs Initiative (SARChI) programme (Phytochemical Food Network to Improve the Nutrition for the Consumers; Grant Number 98352) is greatly acknowledged.