Recently, strawberries have started to hit the market one after another. As a popular winter fruit, with its hot sales, various rumors have reappeared: "Large strawberries have been treated with swelling agents" "Nowadays, many are 'technological strawberries'"... Is swelling agent used in strawberry cultivation? Recently, reporters interviewed farmers and relevant experts. Expanding agents are not new or prohibited chemicals. ”Botany PhD and popular science writer Shi Jun introduced that the scientific name of the swelling agent is Chlorpyriprole (CPPU), which is a plant growth regulator widely used in crops such as kiwifruit and cantaloupe. Its mechanism of action is to regulate the levels of endogenous hormones in plants, promote the double secretion of cytokinins by plant cells, increase the number of cell divisions per unit time, and promote the secretion of auxin, resulting in larger cell growth and an increase in fruit volume. How is the use of swelling agents in actual planting? In the greenhouse of Houhuojia Strawberry Professional Cooperative in Langao Town, Longkou City, Shandong Province, farmer Cao Zuolin told reporters that local strawberry cultivation does not rely on swelling agents. Taking the locally grown variety "Zhangji" as an example, if an expanding agent is used, the seeds on the surface of strawberries will protrude significantly, while the seeds on the surface of normal strawberries are mostly concave. Lu Changhu, the secretary of the Houhuojia Village Party Branch, introduced that although the use of swelling agents can increase the size of the fruit, it can cause the flesh to become soft and not resistant to storage and transportation, seriously affecting the taste. Local strawberries are mostly sold to other regions through e-commerce, with certain storage requirements of about one week. However, strawberries that use expansion agents have difficulty in preservation and are not cost-effective from an economic perspective. Wu Chong, Associate Researcher at Shandong Fruit Tree Research Institute, stated that plant growth regulators have a high cost, but their effect on improving strawberry yield and quality is limited, and the use of expansion agents does not have economic advantages. In addition, there are rumors online about strawberry ripening. Regarding this, Fan Chonghui, Deputy Director of the Vegetable Station of Longkou Agricultural Technology Promotion Center, said, "Nowadays, growers achieve early maturity by improving cultivation methods, rather than relying on drugs." Why are strawberries generally larger in size on the market now? Wu Chong analyzed that variety updates are an important reason. In recent years, large fruit type, early maturing, and high sweet varieties such as "Zhangji" and "Xiangye" have gradually replaced the previous small fruit type varieties. At the same time, planting techniques are constantly optimized, promoting high-quality fruit enlargement through light and temperature regulation, thinning flowers and fruits, precise water and fertilizer management, etc., which is more in line with market demand and also conducive to improving sales unit price and comprehensive economic benefits. So how are deformed fruits, oversized fruits, and hollow fruits formed? According to experts, the seeds (achenes) on the surface of strawberry fruit are growth hormone synthesis centers that require fertilization to promote normal fruit development. If continuous rainy weather, uncomfortable temperature, etc. interfere with pollination, it is easy to form deformed fruits. In addition, some strawberry varieties themselves have hollow characteristics, and other strawberry varieties may also experience hollow or oversized fruits due to uneven water and fertilizer distribution and large temperature differences during cultivation. Relying solely on the large, deformed, or hollow shape of the fruit does not determine the use of an expansion agent, "said Cao Zuolin. Experts say that at the regulatory level, China has established a quality and safety supervision system for agricultural products that covers all levels. Each township and street has an agricultural product quality and safety supervision agency that conducts irregular inspections of locally produced agricultural products. For products found to have excessive pesticide residues during random inspections, measures such as destruction will be taken in accordance with the law to ensure that the agricultural products supplied to the market meet safety standards, and consumers can purchase and consume them with confidence. (New Society)