The purpose of irrigation is to prevent water stress, especially during the formation of the part of the plant that will be harvested. Water stress can occur in a crop when the soil moisture is excessive or when it’s deficient. When oxygen concentration levels in the soil atmosphere are lowered due to displacement by water for an extended period of time, the root system can be severely damaged. Lettuce and green-leaf plants are especially susceptible to water stress due to their shallow root systems. Water stress can lead to two main problems: Poor yields and poor product quality (in terms of • firmness,.
