The Effect of Intercropping and Deficit Irrigation on the Water Use efficiency and Yield of Tomato (Lycopersicon esculentum Mill) and Basil (Ocimum basilicum)

Deficit irrigation is an optimized solution in which the plants are deliberately allowed to reduce their crop by receiving less water than needed. Combined cultivation is a sustainable and efficient system that can increase water use efficiency by increasing the productivity of soil and water resources. In this regard, a factorial experiment in a completely randomized design with two factors in three replications was carried out. The first factor was three types of cultivars: Monoculture tomato, Monoculture basil and intercropping of 50% tomato and 50% basil, and the second factor was four irrigation periods including irrigation without water stress in the root zone 0.8FC irrigation when the soil moisture in the root zone was about 0.7FC, 0.5FC, 0.3FC. The results showed that the highest water use efficiency based on dry matter yield was obtained, in intercropping at moisture level of 0.5FC. The highest dry matter yield and storability of tomato plant were obtained in intercropps and the highest dry and wet matter yield of the basil plant were obtained in monoculture. The Land equivalent ratioat all levels of moisture was greater than 1, the highest (LER = 2.1) was obtained at a non-stressed levels. Intercropping and irrigation up to 0.5FC level for two basil and tomato plants in addition to having the proper yield, has been able to prevent large amounts of water from being wasted.