Performance of Brassica rapa and Brassica oleracea under Shade net within Coastal Environment

Abstract

Cabbages are important for income generation, human nutrition, and health promotion. Its production in the tropics is constrained by soil moisture stress and high temperatures. Sustainable production requires the adoption of technologies that modify growth environment. A study was conducted to evaluate the performance of Brassica rapa and Brassica oleracea under shade nets within coastal environments. Randomized complete block design, with three replications, was used. Treatments were: 0%, 50% and 70% shading, using black shade net. Data collected include plant height, stem diameter, crown diameter, leaf chlorophyll, number of open leaves and quality heads, and fresh head weight. Data obtained were subjected to ANOVA and means separated using Tukey’s test at 5%. 70%, and 50% shading significantly increased plant height than open field by 7.1cm and 5.3cm respectively. Number of open leaves and leaf chlorophyll content in both cabbages decreased with increase in shading intensity. Brassica rapa under 70% and 50% shading had 55% and 47.5% more yield than open field respectively, while Brassica oleracea under 70% and 50% shading had 62.5% and 53% more yield than open field respectively.  Brassica rapa under 70% shading had 0.8 kg more fresh weight per plant than open field while 50% had 1 kg. Brassica oleracea had 1 kg more fresh weight per plant than open field in both 70% and 50% shading. Therefore, black shade net of 50% and 70% shading favoured cabbage production in a coastal environment and they can be used in areas with similar ecological conditions.