Development and implementation of an early warning system for irrigation in intensive tomato seedling cultivation

During tomato seedling cultivation, the growing medium and irrigation strategy directly influence seedling growth and determine seedling quality. In this study, the effects of different growing media and irrigation volumes on seedling development were investigated, revealing that tomato seedlings grown with a medium porosity of 0.56 and an irrigation volume of 80–90 % of the medium porosity showed good quality. Then, to optimize the irrigation strategy for tomato seedlings, a warning model was developed to determine proper irrigation timing. The water consumption of seedlings at different developmental stages (one-leaf-one-apex (I), two-leaf-one-apex (II), and three-leaf-one-apex (III)) was monitored and analyzed. This model integrates environmental parameters with seedling water consumption to trigger warnings when substrate moisture levels drop to those that could cause wilting. Furthermore, greenhouse validation results showed that the predicted water consumption at each stage matched the actual water use. The model can guide the creation of an automated irrigation control system during seedling growth, establish standardized production methods, and reduce labor costs. • The appropriate medium porosity and irrigation volume for cultivating tomato seedlings were evaluated. • The impact of light intensity, temperature, and humidity on the water consumption of tomato seedlings was assessed. • A warning model was developed to trigger warnings when substrate moisture drops to levels that may lead to wilting. • Greenhouse validation showed that the predicted water consumption matched the actual water use.