Use Plant hormone to control excessive vegetative growth preserve flowers and fruit and promote ripening and yield increases

The key to applying plant growth regulators lies in aligning them with the crop's critical growth stages.
The goal is to precisely control excessive vegetative growth, preserve flowers and fruit, and promote ripening and yield—all without disrupting the plant's natural growth rhythm.
Below are the critical application stages for common major crops:

Corn
‌Key Stage: 6–10 leaf stage (early jointing stage)‌
Function:Spray growth retardants (e.g., DA-6, Ethephon) to shorten basal internodes, lower ear height, and stimulate aerial root development, thereby significantly enhancing lodging resistance.
Supplementary Stage: 7 days before tasseling; spray in combination with Brassinolide to boost pollen viability, reduce "bald tips" (incomplete kernel filling at the tip), and increase the thousand-kernel weight.

Peanut
‌Key Stage: Late full-bloom stage; when pegs begin to penetrate the soil in large numbers‌
Function:Spray Uniconazole or Prohexadione-calcium to control excessive vegetative growth, encourage pegs to penetrate the soil, and increase the number of productive pods.
Supplementary Stage:Pod-filling stage; foliar spray of Sodium Nitrophenolate combined with Potassium Dihydrogen Phosphate to improve kernel fullness and reduce empty shells or shriveled pods.

Solanaceous Vegetables (Tomato, Pepper, Eggplant)
‌Key Stage: Early bloom to full bloom‌
Function:Apply anti-drop agents (e.g., 4-CPA) or Brassinolide via blossom dipping or spraying flower clusters to reduce flower and fruit drop caused by low temperatures and overcast/rainy weather, and to improve fruit set.
Supplementary Stage: Early fruit expansion stage; spray Amine Fresh Ester (DA-6) to promote uniform fruit enlargement, reduce fruit deformity, and enhance marketability.

Grape
‌Cluster Elongation Stage: 7–10 days before flowering‌; dip flower clusters in a low-concentration GA3 solution to elongate the cluster structure and prevent fruit deformation caused by overcrowding later on.
‌Fruit Retention Stage:Within 2 days after petal fall‌; dip clusters in a low-concentration mixture of GA3 and Forchlorfenuron (CPPU) to reduce physiological fruit drop and ensure uniform fruit set. **Fruit Enlargement Stage:** 10–15 days after fruit set, when berries reach the size of soybeans, apply an enlargement formula (via dipping) to promote berry expansion and increase individual berry weight.

Strawberry
Flower Bud Differentiation Stage: Two weeks prior to flower bud differentiation, spray with a low concentration of gibberellin to induce earlier differentiation.
Vegetative Growth Control Stage:After transplanting and seedling recovery, spray with Paclobutrazol or Uniconazole to inhibit excessive stem and leaf growth, thereby concentrating nutrients for flower bud development.
Early Flowering Promotion Stage: Two weeks before flowering, apply a low concentration of gibberellin again to accelerate flowering and facilitate an earlier market launch.

Winter Wheat
Seed Treatment Stage: Treat seeds with Chlormequat Chloride or Paclobutrazol before sowing to promote root development, cultivate short and sturdy seedlings, and enhance cold tolerance for overwintering.
Post-Greening Growth Control Stage:During the jointing stage, spray Chlormequat Chloride on fields showing excessive vegetative growth to shorten basal internodes and prevent lodging later in the season.

General Key Principles
Avoid applying plant growth regulators during the peak flowering stage, particularly during the hottest part of the day (noon), to prevent chemical burns to the flower parts and avoid phytotoxicity.
For crops with weak vigor, it is not advisable to force the application of growth-control agents; instead, restore plant vigor through fertilization first, then apply regulators as needed.
Sensitivity to growth regulators varies significantly among different varieties; conduct small-scale trials before initial use to verify the appropriate concentration and timing before proceeding with large-scale application.