There are many kinds of plant growth retardants on the market that can control excessive growth. Today we will compare and introduce several common products to help you make better choices.
Pros and Cons of Paclobutrazol:
Advantages: remarkable effect in controlling growth, wide range of applicable crops, very cheap price and long efficacy period.
Disadvantages: large amount of soil residue and long residue period (Paclobutrazol soil residue period can be up to 6-8 months).
It has a great negative impact on soil damage (drips or sprays into the soil), and it is also easy to cause phytotoxic effects on current and next crops (the dosage concentration is too high or the number of uses is too high and too frequent), for example, if the current crop appears Seedling growth is slow, excessively dwarfed, leaves are shrunken, curled, deformed and easy to fall early, “dumb flowers” do not bear fruit after flowering, underground stems have small deformities, etc. For example, in the next crop, the seeds do not germinate, do not emerge, or emerge late, Deformed seedlings, etc.
Advantages and disadvantages of Uniconazole:
Advantages: Strong drug activity, fast effect, stronger growth control effect and fast degradation, not easy to affect subsequent crops (all aspects of the effect are more than 3 times stronger than Paclobutrazol);
Disadvantages: The soil residue period is relatively large, the residue period is relatively long, and it will affect the growth of subsequent crops (the residue amount and residue period are only 1/5-1/4 of Paclobutrazol). If the dosage concentration is too high, it will cause crop damage, such as seedlings not growing, young leaves burning and withering, leaves falling abnormally, and a large number of flowers and fruits falling.
Uniconazole has a relatively large damage to water quality and is highly toxic to aquatic organisms such as fish and shrimp.
Advantages and disadvantages of Chlormequat Chloride and Mepiquat Chloride:
More mild and slower to take effect than Paclobutrazol and Uniconazole. They can be used in any growth period of most crops and are safer to use. They can be used at low concentrations even in the seedling stage and flowering and fruiting stage. However, Paclobutrazol and Uniconazole are only suitable for long-term use when the stems, leaves and branches are slightly vigorous;
Chlormequat Chloride and Mepiquat Chloride have weaker and worse control ability and control effect. If the amount of pesticide used for control is too small or the number of control times is too small, it is easy to fail to control the vigorous growth of crops, or the crops will rebound and continue to grow vigorously after a period of time after spraying pesticides;
Neither Chlormequat Chloride nor Mepiquat Chloride is suitable for use when the growth period is relatively short and severe vigorous growth has occurred (poor control effect);
Simply comparing Chlormequat Chloride and Mepiquat Chloride, Chlormequat Chloride Chloride is slightly more active, has a stronger growth control effect, and has a longer duration of efficacy than Mepiquat Chloride; Chlormequat Chloride and Mepiquat Chloride generally require 2-3 consecutive sprayings (even more sprayings or spraying at shorter intervals are required in hot and rainy seasons, otherwise the vigorously growing crops may not be controlled or killed).
Paclobutrazol, Uniconazole, Chlormequat Chloride, Mepiquat Chloride, these products for controlling vigorous growth, after being sprayed on crops, all have a suppressive and controlling effect on the GA1, GA3 gibberellins that promote vegetative growth and the GA4, GA7 gibberellins that promote reproductive growth in the crops (delaying the synthesis rate and reducing the synthesis amount), that is, inhibiting the growth of crop stems and leaves as well as the formation and development of crop flowers, fruits, ears, and tubers;
Prohexadione Calcium only inhibits the synthesis and accumulation of GA1 and GA3 gibberellins in crops, but not the synthesis and accumulation of GA4 and GA7 gibberellins, which will bring a unique vigorous growth control effect – Prohexadione Calcium only suppresses the vegetative growth of crops, does not control the vigorous growth of crop seedlings, and does not suppress the reproductive growth of crops, does not control the formation of normal yields such as flowering and fruiting/heading and grain/tuber development of crops.
In short, Prohexadione Calcium has the characteristics of controlling branches and leaves but not flowers and fruits, very low toxicity, very high absorption efficiency (it can be fully absorbed by crops within a few hours after spraying), extremely fast degradation speed (its residual validity period in crops is only 1-2 weeks, and it can be completely decomposed in the soil in up to 40 days), extremely short soil residual period (half-life in the soil is less than 24 hours), almost completely decomposed without residue (it will eventually decompose into water and carbon dioxide in the soil), almost pollution-free (it does not accumulate in the soil and does not produce any harmful substances after decomposition), and almost no impact on the next crop. Green environmental protection is one of its biggest features.
Compared with Paclobutrazol, Uniconazole, Chlormequat Chloride, and Mepiquat Chloride, Prohexadione Calcium is a more cost-effective control of vigorous growth.