The article presents a model that helps understand how apples and pears grow by analyzing the impact of environmental conditions on fruit quality. The model shows that fruit growth is driven by water and sugar accumulation, controlled by cell properties. It accurately predicts changes in fruit mass and sugar content under different environmental conditions. The model highlights the importance of factors like active transport, cell flexibility, and plant water levels in fruit growth. This research can help improve fruit quality and predict how stress conditions affect fruit growth.