How to spray plant growth regulators on jujube trees

Plant growth regulators can enhance cell metabolism, promote cell division, and significantly increase the fruit setting rate of jujube trees. Commonly used ones include Gibberellic Acid GA3, 2.4-D, Naphthalene acetic acid (NAA) and Paclobutrazol (Paclo), which have obvious effects on promoting flowering and fruit retention of jujube trees. Gibberellic Acid GA3 is the most widely used in production.

Gibberellic Acid GA3
Generally used in the early flowering period of jujube trees, when the fruiting branches of jujube trees have 5 to 8 flowers, spray 10 to 15 mg/kg of Gibberellic Acid GA3 once, which can promote pollen germination, stimulate unpollinated jujube flowers to bear fruit, and increase fruit setting by 1 to 2 times. At the same time, it can be mixed with micro-fertilizers and pesticides for spraying without reducing the effect.

Naphthalene acetic acid (NAA)
Spraying 20 mg/kg of Naphthalene acetic acid (NAA) or 20 mg/kg of PCPA three times during the flowering and young fruiting period of jujube trees can increase fruit setting by 60%. Spraying 40-80 mg/kg Naphthalene acetic acid (NAA) after the jujube tree blooms can reduce fruit drop by 23%-42%.

2.4-D
Spraying 20 mg/kg of 2.4-D aqueous solution during the flowering period of the jujube tree can increase the fruit setting rate by 40%; spraying 30-50 mg/kg of 2.4-D after flowering can reduce fruit drop by 35%-40%.

Paclobutrazol (Paclo)
Paclobutrazol (Paclo) is a growth retardant that can effectively control tree development, inhibit the growth of new shoots, thicken leaves, and deepen green. It is used in dwarfed and densely planted jujube orchards, and the effect is very obvious. The general concentration used for jujube saplings is 800-1000 mg/kg, and the concentration used for mature trees is 2000-2500 mg/kg. It is carried out before flowering (late May), that is, when the jujube hangs 8-9 leaves. The spraying amount is preferably dripping water on the leaves.

Chlormequat Chloride (CCC)
In late May, young jujube trees were sprayed with 2,500 to 3,000 mg/kg of Chlormequat Chloride (CCC) every 15 days for a total of two sprays. The crown of the tree can be shortened by 17% to 30% compared with the control, and the fruit setting rate can be increased by 2.26%.