4-Chlorophenoxyacetic Acid (4-CPA):
----Professional Plant Growth Regulator Specification
4-Chlorophenoxyacetic Acid, commonly known as 4-CPA, is a highly effective synthetic plant growth regulator widely used in global agriculture. This plant growth regulator targets key physiological processes of crops, helping farmers solve common issues like fruit drop and uneven ripening, while also boosting yield and quality—making it a staple for high-value fruit and vegetable cultivation.
Core Functions of 4-Chlorophenoxyacetic Acid (4-CPA)
As a versatile plant growth regulator, 4-CPA primarily excels in three key areas: first, it promotes fruit setting by stimulating ovary development, reducing flower and fruit drop caused by environmental stress (such as low temperature or drought). Second, 4-Chlorophenoxyacetic Acid regulates fruit ripening, ensuring uniform maturity to simplify harvesting and extend shelf life. Third, this plant growth regulator enhances cell expansion, leading to plumper fruits and increased single-fruit weight without compromising taste or nutritional value. Notably, 4-CPA is non-toxic to crops when used as directed, making it safe for both field-grown and greenhouse crops.
4-Chlorophenoxyacetic Acid (4-CPA) Application Scenarios & Usage Guidelines
1. Tomato (Field & Greenhouse)
Tomatoes are highly responsive to 4-Chlorophenoxyacetic Acid, especially in cool seasons when natural fruit setting is poor. As a targeted plant growth regulator, 4-CPA should be applied at the early flowering stage (when 2-3 flowers per cluster are open). Dilute 4-CPA to a concentration of 10-20 mg/L, then spray evenly on flower clusters or dip each cluster briefly in the solution. For greenhouse tomatoes, reduce the concentration to 8-15 mg/L to avoid excessive vegetative growth. This application reduces fruit drop by 30-40%, increases fruit setting rate by 25-35%, and results in 15-20% higher overall yield.
2. Cucumber (Greenhouse)
Cucumbers often suffer from poor female flower formation and fruit abortion in high-temperature environments. Use 4-CPA, a reliable plant growth regulator, at the seedling stage (when 3-4 true leaves appear) and early flowering stage. Dilute 4-Chlorophenoxyacetic Acid to 15-25 mg/L and spray the leaf surface and growing points. This promotes female flower differentiation (increasing female flower ratio by 20-30%), reduces empty vines, and enhances fruit development—with single-fruit weight increasing by 10-15% and harvest period extended by 7-10 days.
3. Apple (Orchard)
Apples face issues like premature fruit drop and uneven fruit size. Apply 4-CPA, an efficient plant growth regulator, twice: first at the fruit expansion stage (30-40 days after flowering) with a 20-30 mg/L solution, and second 20-25 days before harvest with a 25-35 mg/L solution. Spray the entire tree, focusing on fruit surfaces. 4-Chlorophenoxyacetic Acid reduces pre-harvest fruit drop by 40-50%, improves fruit color uniformity, and increases soluble solid content by 0.8-1.2 percentage points—elevating the proportion of premium-grade apples by 15-20%.
4. Grape (Vineyard)
Grapes are prone to berry splitting and uneven ripening. Use 4-CPA as a plant growth regulator at the berry hardening stage. Dilute 4-Chlorophenoxyacetic Acid to 15-20 mg/L and spray evenly on grape clusters, avoiding direct contact with young leaves. This strengthens berry skin toughness (reducing splitting by 30-35%), promotes uniform sugar accumulation, and advances ripening by 5-7 days—while maintaining grape flavor and aroma.
Key Notes for Safe Use
Do not exceed the recommended concentration of 4-CPA, as excessive use may cause leaf curling or deformed fruits.
Apply 4-Chlorophenoxyacetic Acid in the morning (8-10 AM) or evening (5-7 PM) to avoid high-temperature evaporation, which ensures better absorption.
This plant growth regulator is compatible with most common fungicides and insecticides, but a small-scale compatibility test is recommended before mixed use.
4-Chlorophenoxyacetic Acid (4-CPA) stands out as a cost-effective plant growth regulator, offering targeted solutions for diverse crops. Its clear usage guidelines and reliable results make it an essential tool for farmers aiming to improve crop productivity and market competitiveness.
