Low Water Tensions in Defined Growth Stages of Processing Tomato Plants and their Effects on Yield and Quality

In drip irrigation experiments where water was applied daily it was found that low water tensions could be maintained in the soil to a range of 10 to 20 centibars and that these conditions had a considerable influence on yield and quality of processing tomatoes, Lycopersicon esculentum cv VF 317. The response of the plant in different growth stages to low soil water tensions was studied. Irrigation during the period of fruit set and fruit development was found to increase yield levels by 53 t ha^-1 compared with non-irrigated plants. Irrigation applied only during the period of fruit development had a favourable influence on yield as well as on the efficiency of water utilization. However, irrigation at this stage had an unfavourable influence on fruit quality characteristics, namely, total soluble solids, acidity, viscosity and vitamin C. The effects of irrigation on fruit set and fruit development are discussed.