Effect of Deficit Irrigation at Different Growth Stages on the Yield and Water Productivity of Tomato at Adami Tulu Agricultural Research Center

Improving irrigation water management and increasing water productivity are critical to address future water scarcity in arid and semi-arid areas. A promising strategy is to maximize water productivity by exposing crops to a certain level of water stress. The experiment was conducted on-site at the Adami Tulu Agricultural Research Center to study the effect of deficit irrigation at different growth stages on agronomic parameters as well as yield and yield components as well as water productivity of tomato plants. Treatments consisted of a factorial combination of full and three-deficit irrigation with four plant growth stages. The results showed that the interaction effect between deficit irrigation and different plant growth stages significantly affected plant height, fruit height, fruit diameter, fruit yield and water productivity. The highest plant height (75.23 cm), fruit length (84.56 mm), fruit diameter (77.10 mm), marketable fruit yield (48.64 t/ha) and total fruit yield (50.09 t/ha) were obtained under continuous full irrigation achieves levels. While the lowest plant height (54.43 cm), fruit length (55.92 mm), fruit diameter (50.04 mm), marketable yield (22.51 tons/ha) and total yield (28.14 tons/ha) at 60% Etc achieved in the middle were stage treatment. The highest water productivity of 7.85 kg/ha was achieved with the application of 80% ETc in the late season, while the lowest (4.61 kg/ha) was achieved with 60% ETc in the middle treatment phase. Therefore, the results of this study suggest that applying 80% ETc deficit irrigation in the late season stage is the best solution for water conservation without affecting tomato yield while improving water productivity under water-stressed conditions.