Paclobutrazol is a highly active plant growth regulator, which has the effects of delaying plant growth, inhibiting stem elongation, shortening internode, promoting flower bud differentiation, increasing plant stress resistance, and improving yield. The application of paclobutrazol on fruit trees has obvious effect, the yield has increased significantly, and good economic benefits have been obtained.

Application technology of paclobutrazol on peach trees

1、 Inhibit the growth of new shoots

Soil root application: when the peach bud germinates to 2cm long, apply the pesticide in the ring ditch at the root zone of each mature peach tree. The amount of pesticide applied to each tree can be 10-15g of 15% paclobutrazol wettable powder, which can effectively inhibit the growth of new shoots of peach trees, reduce the consumption of nutrients, significantly increase the number of flower buds, shorten its length, make the leaf color dark green, increase the chlorophyll content, and increase the dry matter of leaves. At the same time, it can improve the cold resistance of flower buds, improve the fruit setting rate, and significantly increase the yield. Due to the continuous absorption of the root system, soil application has a continuous inhibition effect. The dynamic fluctuation of the new shoot growth is small, and the inhibition effect on the new shoot growth of the peach tree in the year is obvious. The inhibition effect on the growth of the peach tree in the second year is large, and it begins to ease in the third year. High-dose treatment still had strong inhibition on new shoots in the third year. Soil application is prone to over-inhibition. The residual effect of soil application is long and will be stopped the next year.

Leaf spraying: when the new shoots grow to 30 cm long, use paclobutrazol 1000~1500 mg/L to spray, the effective inhibition period is about 20 days, and then the inhibition is more moderate, and the growth dynamics of new shoots fluctuate greatly.

Trunk smearing method: In the growing season or dormancy period, mix the paclobutrazol wettable powder with water in a small tea cup, and then smear it on the branches below the main branch with a small brush, with the same amount as soil application.

Attention should be paid to the use of paclobutrazol: the dosage and concentration of paclobutrazol should be strictly controlled according to the local environment and peach varieties to avoid excessive inhibition of peach growth, and paclobutrazol should not be used for consecutive years.

The application effect of paclobutrazol on fruit trees is obvious. A large-scale production experiment was carried out on 4-6-year-old mango trees. The results showed that the treatment flowered 12-75 days earlier than the control, and the amount of flowers was large, the flowering was neat, and the harvest period was also 14-59 days earlier, the yield was significantly increased, and good economic benefits were obtained.

Paclobutrazol is a plant growth regulator with low toxicity and obvious effect, which is widely used at present. It can inhibit the biosynthesis of gibberellin in plants, thus inhibiting the vegetative growth of plants and promoting flowering and fruiting. Practice has proved that the growth of mango shoots can be effectively inhibited and flowering can be promoted by applying 10 grams of paclobutrazol (effective ingredient 15%) to each 3-4-year-old mango tree. In September 1999, the South Asian Tropical Crop Research Institute of the Chinese Academy of Tropical Agricultural Sciences applied 10 grams of commercial PP333 to the 3-year-old Tainong No. 1 and 4-year-old Aiwenmang and Zihuamang per tree soil, which increased the heading rate by 80.7% - 100% compared with the control (without PP333). The method of applying paclobutrazol is to dissolve paclobutrazol in water and evenly apply it in the ditch and cover it with soil after opening a shallow ditch in the tree crown drip line. If the weather is dry within 1 month after the application, the soil shall be properly watered to keep the soil moist.