There are two main factors that affect the expansion of strawberry fruit: internal and external factors. Therefore, it is a very key factor whether strawberries undergo a good pollination and fertilization process when they bloom. Only after pollination and fertilization can endogenous hormones such as IAA and CTK be produced in seeds to promote fruit expansion. If cultivated in greenhouse, the lack of insects needed for pollination often leads to poor pollination and fertilization, which leads to fruit expansion failure. On the other hand, whether the temperature is suitable during fruit development is a key factor. The temperature is too low for strawberry fruit to expand. Therefore, strawberry must be cultivated in greenhouse in winter to ensure the growth temperature; At the same time, wallbees or bees are placed in the strawberry shed to facilitate pollination. Sometimes artificial pollination can also be used, that is, some strawberry flowers are collected (which plays the role of flower thinning) and pollinated by others. Another method (some people may think it is harmful to human body, but it is actually quite safe) is to spray 1- 10mg/L of naphthylacetic acid or clofenurea. This kind can also promote fruit expansion. In addition, if soil nutrients are insufficient, plants grow poorly, or diseases and pests breed, fruit expansion may be blocked. Topdressing, spraying or other targeted methods can be selected according to the actual situation. I wish you a fruitful harvest!