The response of pear tree and fruit growth to the water stress applied during different growing stages of pear tree

The study was conducted to investigate the influence of water deficit applied at different stages on the growth and fruit yield of pear trees. The experiment included five treatments: control, the full irrigation during the whole growing stages; T1: moderate water deficit irrigation applied during the vegetative growth stage and full irrigation applied during the other stages; T2: severe water deficit irrigation applied during the vegetative growth stage and full irrigation applied during the other stages; T3: moderate water deficit irrigation applied during the fruit enlargement stage and full irrigation applied during the other stages; T4: severe water deficit irrigation applied during the fruit enlargement stage and full irrigation applied during the other stages. The results indicated that the water deficit irrigation applied during the vegetative period significantly decreased shoot growth, whereas no obvious negative impact on fruit growth and final fruit yield were observed. Fruit yield was significantly decreased by the water stress applied during the fruit enlargement stage, but no significant differences in vegetative growth were detected between the control and the water deficit irrigation applied during the fruit enlargement stage. Though vegetative growth was sensitive to water stress, shoot growth ceased after June and the water stress in fruit enlargement stage had no impacts on the shoot growth. However, fruit rapidly grew during this stage, thus the water stress applied during the fruit enlargement stage damaged fruit growth and decreased final fruit yield.