Regulated deficit irrigation can affect how well greenhouse grapes photosynthesize and transpire. In a study, researchers found that applying moderate water stress during the sprout stage can improve water use efficiency. The net photosynthetic rate, transpiration rate, and stomatal conductance were all linked, with a positive correlation between them. Under regulated deficit irrigation, the relationship between net photosynthetic rate and stomatal conductance was stronger compared to normal watering, suggesting that some water stress can help plants better control their environment through their stomata.