Investigating the effect of trellising and stem training methods on the horticultural performance of indeterminate tomatoes grown in dome shape tunnels.
Growing of tomato in open field in South Africa is very challenging due to unfavorable environmental conditions, pests and diseases. This has resulted to an increased hydroponic production of tomatoes in protected cultivation. However, protected cultivation require many horticultural practices for optimum production. The first experiment of the study was conducted to evaluate the effect of different trellising methods namely, early layering, late layering and vertical trellising in response to leaf gas exchange and chlorophyll fluorescence of indeterminate tomato produced in tunnels. The second experiment was conducted to assess the effect of trellising method on growth, yield and quality parameters of indeterminate tomato. The third experiment investigated effects of different stem training methods namely, single stem, double stem and two plant per pot in line with growth, yield and physiological responses of indeterminate tomato grown in dome shape tunnels.The results of the first study showed that early and late layering increase photosynthetic rate (A), transpiration rate (T), the effective quantum efficiency of photosystem II photochemistry (ФPSII) and electron transportation rate (ETR) compare to vertical trellising. The second study revealed that early and later layering increase plant height, number of fruit and fruit mass compare to vertical trellising. However observed results showed no variation among trellising methods with quality parameters. The third experiment on leaf gas exchange results showed high photosynthetic rate (A) and stomatal conductance (gs) in single and two plants per pot stem. Single stem exhibited high plant height and stem diameter with double and two plants per pot stem. Single stem and double stem showed high number of fruits, and fruits mass compare to two plants per pot stem training. The study also showed high colour index, total soluble solids (TSS), titratable acids (TA), and BrimA with double stem and two plants per pot than single stem. Therefore, the presented results revealed that early and late layering trellising methods can be the best methods that can be used by resource-constrained farmers in dome shape tunnel to increase physiological efficiency, growth and yield. On the other hand double stem and two plants per pot training method can had a potential to improve yield and quality of indeterminate tomato grown in tunnel.
Masters Degree. University of KwaZulu-Natal, Pietermaritzburg.