In the fruit consumption market, strawberries with large and beautiful fruits and red colors are often favored by consumers. How to promote the expansion and yield of fruits and the uniform and beautiful coloring in the process of strawberry planting has become the focus of growers.

The expansion of strawberry fruit is mainly determined by the increase of the number of fruit cells (flower bud differentiation stage) and the expansion of cell volume. What are the factors that affect the expansion of strawberries? The following points are summarized:
　　1. strawberry flower organ
The number of strawberry cells was regulated in the stage of flower bud differentiation, and the quantity and quality of flowers were improved. Secondly, to ensure the quality of flowering, strawberry flowering requires high temperature and low humidity management, temperature control at 22-25 ℃, soil water content control at 40-50%, is conducive to fruit expansion.

　　2. fruit thinning and fruit enlargement
In the process of planting, there is a saying that early fruit thinning is not thinning flowers, fruit thinning is going to the library, and the plant "fruit setting fatigue" is reduced. Timely removal of deformed and bad fruits during the planting process is conducive to reducing nutrient loss. Generally speaking, grade 1 top fruit necrosis picking is beneficial to increase the weight of grade 2 fruit.
3. Temperature and Humidity Management and Fruit Expansion
Fruit expansion period, day temperature: 20-25 ℃; Night temperature: 5-10 ℃. The field capacity was maintained at 50-60%.
(1) Low temperature, night temperature below 5 ℃, lasting 3-5 days, plant dormancy, slow expansion.
(2) high temperature, the night temperature is higher than 10 ℃, the fruit is early ripening, and the expansion is blocked.
　　4. nutrition and regulator regulation
The use of cytokinin, brassinolide regulators and timely supplementation of potassium, calcium, boron, zinc and other elements in the fruit expansion stage of strawberry can promote the expansion and sweetening of strawberry and increase the brightness and hardness of fruit.
Jiangxi Xinruifeng focuses on solving the difficulties in crop cultivation and has carried out experimental demonstration on strawberry swollen fruit. The situation is as follows:
Test Demonstration Product: Xinruifeng Strawberry Inflation Package(Meng Enemy + Zhaojiaguo + Rui Zhaofeng)
Test demonstration varieties: Hongyan
Test and demonstration technology: spray the whole plant when most top fruits of strawberries begin to turn white (fruit transverse diameter 1.5-2.0cm).
Test medication time: December 17, 2021 Test return visit time: December 22, 2021
Demonstration site: Strawberry Planting Demonstration Base, Shiguan Road, Shifang City, Deyang City, Sichuan Province

On the left is the photo record before medication on December 17, 2021, and on the right is the photo record 5 days after medication on December 22, 2021.
　　

Table 1 Effect of Xinruifeng Quality and Yield-increasing Package on Strawberry Fruit Diameter Expansion

Through the effect return visit and data analysis, it can be seen that the strawberry fruit swelling effect under the treatment of Xinruifeng quality-improving swelling fruit package is good, and the average fruit diameter after 5 days of medication is 3.61mm larger than that of the control treatment. The increase in fruit diameter and the swelling rate are higher than those of farmers' self-use swelling fruit treatment, and the performance is more obvious in medium and small fruits. In addition, from the comparison chart before and after the test, it can be seen that the strawberry treated by Xinruifeng has large fruit shape, fast color change and red color, which can promote early maturity and listing.
　Recommendations:At present, strawberry cultivation is mainly in greenhouse. Strawberry can be picked many times as a mixed flower and fruit crop, so it can be used twice in the young fruit period of strawberry with an interval of 10-15 days. (Strawberry is affected by varieties, local microclimate, cultivation and management techniques and other factors, and the specific medication plan is adapted to local conditions.)
　　Note:
① Strawberry fruit upgrading package should be used together with fertilizer for better effect, and avoid using together with pesticides and alkaline pesticides as far as possible.
For users and regions with no experience in the use of regulators, it is recommended to test a small area first, and then use a large area if the effect is good.