Flower and fruit thinning agents are plant growth regulators that induce the abscission of a portion of flower buds or young fruit. Commonly used agents include dinitro-o-cresol (DNOC), 1-Naphthylacetic acid (NAA), phenylacetamide, and ethephon.

Brassinosteroids respond to high-temperature stress by activating protective enzyme systems to maintain cell membrane stability, regulating stomatal opening and closing to reduce water loss, and promoting cell division to accelerate the repair of damaged tissues.

For summer crop drought resistance, the preferred choices are Brassinolide, DA-6, Sodium Nitrophenolates (Atonik), and Fulvic Acid-based regulators; combining these with foliar sprays of potassium dihydrogen phosphate yields the best results.

Gibberellic Acid (GA3) is a plant hormone that promotes stem and leaf growth, reduces the shedding of cotton buds and bolls, increases barley yields, and improves fruit set rates for crops such as grapes, citrus, and pears.

To improve fruit set in sweet cherries, a Gibberellic Acid (GA3) solution at a concentration of 20–40 mg/kg can be sprayed during full bloom, or a 10 mg/kg solution can be applied 10 days after flowering. Methods to promote cherry fruit growth include:

The scientific application of plant growth regulators to manage the growth and development of fruit trees represents a new approach to producing high-value fruit. These regulators are versatile: they can either promote seed germination or prolong dormancy; stimulate shoot elongation or inhibit/delay shoot growth;

Extensive trials indicate that most plant growth regulators have a noticeable effect on the green foliage of plants. Among them, Mepiquat chloride, Chlormequat chloride, and Paclobutrazol are the most effective.

Forchlorfenuron (KT-30) is often used in combination with gibberellin. Trials have shown that spraying Kyoho grape clusters once with a mixture of Forchlorfenuron (KT-30) and gibberellin—10 and 20 days after full bloom—allows seedless berries to grow to the same size as seeded ones, increasing fruit size by up to 50%.

Physicochemical Properties and Identification of Natural Brassinolide,White crystalline powder; melting point 256–258°C; solubility in water 5 mg/kg; readily soluble in organic solvents such as methanol, ethanol, and acetone.