Multilocational Evaluation of Growth and Antioxidant Content of Curly Kale (Brassica oleracea L. var acephala) and Chinese Kale (Brassica oleracea var. alboglabra) in Sri Lanka

Abstract

Curly kale (Brassica oleracea var. acephala) and Chinese kale (Brassica oleracea var. alboglabra) are cruciferous vegetables, which have recently gained great popularity in the world as a ‘superfood’. Generally, kale has the capacity to tolerate diverse climatic conditions while demanding fewer inputs, thus making it possible to cultivate them with a minimum cost for crop management. However, kale is still not widespread in Sri Lanka as a vegetable. Therefore, it has not been a commercialized crop to date. This study was conducted to explore the potential for cultivating kale in Sri Lanka. Two cultivars of curly kale (‘Dwarf green curled’ and ‘Winterbor F1’) and Chinese kale were cultivated in three agro-climatic zones representing three main climatic zones in the country, namely the Mid-Country Wet Zone, Mid country Intermediate Zone and Low-Country Dry Zone, using three different media (M1: Existing soil in each location; M2: Sand and coir dust mixture – ratio 1:1; M3: Sand, coir dust, and soil - ratio 1:1:1) at each location. The experiment was carried out as a three-factor factorial with three replicates as a pot experiment. Based on the present study results, even though all the varieties displayed a significantly (p < 0.05) higher growth in terms of dry matter accumulation in the Wet Zone, the growth in the other two locations was also found to be satisfactory. Dry matter accumulation was not significantly different among the varieties within each location. Different media did not have a significant influence on growth. Even though the antioxidant contents in all varieties varied among locations, the values were within the acceptable range. Therefore, both curly kale and Chinese kale can be successfully grown in the tested locations in Sri Lanka and can be easily introduced to local consumers as a ‘superfood.