The Impact of Shading on Growth and Yield of Cabbage (Brassica oleracea L.) in the Low Country Dry Zone, Ampara, Sri Lanka

Abstract

Shade level is a predominant factor that greatly influences growth, quality and yield of exotic vegetables that are grown in low and mid country dry zone areas. Accordingly, a field trial was conducted to investigate the impact of shading on growth and yield of cabbage var. “Green Coronet” in Ampara District of Sri Lanka during the period of July to November 2020. The experiment was laid out in Completely Randomized Design (CRD) with four replicates. Levels of shades were defined in two treatments as open field condition (40% shade) and 70% shade levels. The growth measurements, plant height, the number of leaves and diameter of rosette were recorded at six and eight weeks after transplanting and Analysis of Variance was performed to determine significant differences among treatments (p< 0.05). Further, the head weight and yield were recorded at the harvesting stage and the results revealed that the cabbage plants grown at 70% shade level showed significantly (p<0.05) better performance in the measured growth parameters viz. plant height, diameter of rosette, number of leaves especially after 50 days of transplanting (8WAP) and yield parameters, average head weight and final yield. The lowest performance was observed in plants grown at open field conditions with 40% shade level. It can be concluded that the plants grown at 70% shade level would obtain high growth and yield with the modified temperature, relative humidity level and optimum light intensity in the protected environment. These findings will be beneficial for the farmers to grow cabbage in low country dry zone at commercial scale to obtain higher yields rather than cultivating in open field conditions.

Keywords

• growth
• light intensity
• relative humidity
• shade levels
• yield