Effects of Black Shade Net on Yield of Brassica rapa and Brassica oleracea Cabbages in Kilifi County

Abstract

Cabbage is an important vegetable to humans since it provides crucial nutrients such as fiber, minerals, and vitamins. They also help manage cancer, cardiovascular diseases, prevent type 2 diabetes, and inflammation of the digestive systems. However, its production in the tropics is constrained by climatic and edaphic factors that include soil moisture stress, high soil and air temperatures, high evapotranspiration, and unbalanced nutrition. Due to the above challenges, sustainable cabbage production requires adoption of technologies that can modify the growth environment with minimal environmental effects. A field study was conducted at Pwani University Crop Science farm, Kilifi County, to evaluate the effects of black shade net on yield of Brassica rapa and Brassica oleracea. A randomized complete block design experiment with three replications was set. The treatments included: 50%, 70% black shade net intensity and open field as control. Data collected included, leaf chlorophyll content, fresh head weight, and dry matter weight. The data obtained was subjected to analysis of variance using General Linear Model (GLM) SAS Computer package version 9.1. The results indicated that, shading resulted in decreased chlorophyll content, and that use of 50% and 70% black net shading intensity significantly resulted in 55% and 47.5%, more number of cabbage heads for Brassica rapa than open field respectively, while in Brassica oleracea, 70% shading and 50% resulted in 60% and 52% more cabbage heads than open field respectively.