What is the correct way to use paclobutrazol?

I believe most people don’t know what paclobutrazol is. In fact, it is a plant growth regulator. Its most prominent function is to delay plant growth. It can also promote plant tillering and increase plant stress resistance. Therefore, paclobutrazol can ultimately increase yield. Therefore, paclobutrazol is widely used in agriculture. So how should paclobutrazol be used correctly?

1. Paclobutrazol application method

Common methods used in flower production include soaking (bulbs), soil application, foliar spraying and stem coating. Among them, soaking, soil application and leaf spraying are the most effective, and the efficacy is long-lasting and stable. There are two methods of applying paclobutrazol to the soil. One is for ground-planted foliage and flowering plants, dig a circular trench about 5 cm deep around the crown, evenly sprinkle the fertilizer in the trench and water it in time; the second paclobutrazol is for indoor potted flowers, make holes in the potting soil and apply the fertilizer and water it in time. Foliar spraying is usually carried out in the early stages of growth. The spraying time and concentration of paclobutrazol vary for different flowers, soil types, and nutritional management levels. The method of spraying paclobutrazol is the same as that of general fertilizers and pesticides, but care should be taken to ensure that the growth points are evenly coated with the drug.

2. Paclobutrazol application amount and concentration

It varies depending on factors such as variety, growth, age, and soil quality. The soil application rate is generally 0.25 grams per square meter. When spraying leaves, the concentration of paclobutrazol solution should be between 800 and 1500 ppm. Soak the roots (bulbs) for 5 to 8 hours. The application rate and concentration of paclobutrazol for woody flowers can be slightly higher, while the application rate of paclobutrazol for herbaceous flowers should be lower. Use paclobutrazol with caution on orchids.

3. Paclobutrazol application time

Different paclobutrazol application methods and paclobutrazol application times are different. Soil application is usually carried out before the flower buds sprout in spring (for spring flowers); foliar spray is usually used when the new shoots grow to about 10 to 15 cm. For deciduous flowers and trees, paclobutrazol can be used some time in advance to ensure that the drug takes effect in time.

4. Frequency of application of paclobutrazol

Since paclobutrazol has a long-lasting effect, the effect can generally last for 3 to 5 years after a single application, so the number of applications should be strictly controlled. Soil application should be done at most once every three years, and foliar spraying should be done once a year. If used consecutively, the concentration should be reduced year by year. If the growth is found to be extremely weak, stop using it. If necessary, spray gibberellin to help restore growth.

5. Paclobutrazol stagnation period

Since there is a period of time from the application of paclobutrazol to the effect of the drug, namely the sluggish period of drug efficacy, it is very easy to mistakenly believe that it is "ineffective" in production, thus repeating the application of the drug, resulting in excessive use of paclobutrazol. Before applying pesticides, this factor should be fully considered to avoid losses.