The production of vegetable crops under protection for small-scale farming situations

Abstract

Experiments were conducted with tomato under shade netting and with lettuce in a vertical hydroponic system at the Hatfield Experimental Farm, University of Pretoria. The objectives of the study were: 1. To evaluate the effect of different types of shade netting on tomato production 2. To develop a vertical hydroponic system for lettuce production which would be suitable for use by small-scale farmers. In the tomato trial the highest number of fruit per plant (47) was produced under 12% white shade and 40% black shade nets, and the lowest fruit number (35) was produced under 30% black net. The highest yield of 6.2 kg per plant was obtained under the 18% white net while 30% black net produced the lowest yield of 3.9 kg per plant. The test yield of lettuce grown in plastic tubes with eight vertically arranged plant positions were obtained with a continuous high flow rate of the nutrient solution. However, a simplified manual system where the nutrient solution was delivered by gravity from a small reservoir tank resulted in comparable yields.