From preventing flower drop in tomatoes and eggplants, preventing fruit drop before harvest in apples, promoting grape berry swelling, and then applying inhibitors to promote fruit setting, we have successively applied inhibitors such as indoleacetic acid, 2,4-D, naphthylacetic acid, gibberellin, cytokinin, etc. to promote fruit setting and swelling, so as to achieve the purpose of increasing production and improving quality.
However, when a certain agent is used alone, it often produces side effects such as hollow fruit, cracked fruit, and hardened fruit stalks while improving fruit setting, which cannot meet the requirements of improving quality. It is necessary to mix two or more plant growth regulators, but the compound products must undergo scientific experiments, and their compound active ingredients and contents must be strictly screened, otherwise the effect is not good, and even side effects may occur. The following is an introduction to some commonly used compound preparations of this type.
1. Sodium nitrophenolate + sodium α-naphthylacetate
Its preparation is generally an aqueous solution or soluble powder, which is compounded with high-purity sodium α-naphthylacetate and sodium nitrophenolate. The most common one on the market is 2.85% aqueous solution (1.8:1.05). These two ingredients can enhance each other, broaden the efficacy, and reduce the concentration of use. It has the effect of sodium nitrophenolate activator and the rooting and fruit swelling effect of sodium α-naphthylacetate. It is a broad-spectrum plant growth regulator. Due to the rapid effect of its preparation, it has excellent flower and fruit preservation performance and has become a relatively widespread plant growth regulator variety.
2. Gibberellic acid (GA4+7) + benzylaminopurine
Its preparation is generally an emulsifiable concentrate, a soluble solution or an applicator. The market products include 3.6%, 3.8% emulsifiable concentrate, 3.6% liquid, and 2.7% ointment. It can be absorbed by the stems, leaves, and flowers of the plant, and then transmitted to the active parts of the meristem, promoting fruit setting, promoting the five-rib protrusion of apples, and having a weight-increasing effect. Generally, the flowers are sprayed once during the flowering period, and the young fruits are sprayed once every 15-20 days. In addition, it can also be applied to fruit trees such as kiwi, grapes, and bananas.
3. Choline chloride + naphthaleneacetic acid (sodium)
Its preparation is generally a soluble powder or aqueous solution. The market product has a 25% aqueous solution, which is mainly used in root and tuber crops such as potatoes, sweet potatoes, radishes, onions, and ginseng. This formula is a promoter type, which inhibits the photorespiration of C3 plants, improves the efficiency of photosynthesis, promotes the transportation of organic matter, and transports photosynthetic products to the roots and tubers as much as possible, thereby increasing the yield of roots and tubers.
4. Gibberellic acid (GA3) + CPPU
Its preparation is generally an emulsifiable concentrate or a soluble solution. It is an upgraded product of 0.1% chlorfenapyr soluble solution. The role of adding gibberellin is to prevent side effects such as hardening of the spike axis and uneven size of young fruits. Generally, the use concentration of gibberellin is 10ppm, and the use concentration of chlorfenapyr is adjusted according to the different crops treated, and the use range is 5-20ppm. If this mixture is applied to Kyoho grapes, it is best to use a concentration of 10ppm gibberellin + 5ppm CPPU, which can not only increase the fruit setting rate, but also promote the expansion of young fruits, and significantly increase the weight of single fruit.
5. Gibberellin (GA3) + auxin
Its preparations are generally soluble solutions or soluble powders. When auxins such as α-naphthyl acetic acid, 2,4-D, p-chlorophenoxyacetic acid, β-naphthyl oxyacetic acid, etc. are applied to crops such as tomatoes, mangoes, pineapples, and bananas, while increasing the fruit setting rate, they also produce a certain number of hollow fruits. If used in conjunction with gibberellin, the proportion of hollow fruits is greatly reduced, and the quality is significantly improved.
6. Gibberellin + auxin + benzylaminopurine
Its preparations are mostly pastes. The configuration ratio is 0.3% gibberellin + 0.005% indoleacetic acid + 0.05% 6-BA. The lanolin ointment of this mixture is used to treat the young fruit stalks of new water pears, and the single fruit weight can be increased by 28.6%, and the harvest can be 7-8 days earlier.
7. Chlormequat + choline chloride
Most of its preparations are aqueous. The application mechanism is mainly to increase the fruit setting rate by inhibiting the vigorous growth of new branches. For example, 0.1% choline chloride + 0.05% chlormequat on the market is used to treat grapes when the new branches and leaves have about 6-10 leaves, which can significantly increase the fruit setting. Its use concentration is related to the fertility of the field. If the plant grows vigorously, the concentration is higher, the concentration is lower for medium growth, and it is best not to use it for weak growth.
8. Sodium nitrophenolate + paclobutrazol
Most of its preparations are wettable powders or suspensions. It is mainly used for controlling the shoots and enlarging the fruits of fruit trees. It is also a popular plant growth regulator for fruit trees in recent years. Its application on fruit trees is in the ascendant.
9. Thidiazuron
Thiazuron is mainly used as a cotton defoliant, but it is also a good cytokinin at low concentrations. According to some literature, its biological activity in promoting fruit setting and keeping leaves green is higher than that of 6-BA. Its preparation is a wettable powder or a soluble solution. The market products are 0.1% thiazuron soluble solution and 0.1% thiazuron wettable powder, which are used on zucchini, melon, grapes, and cucumbers. The concentration range is 2-4ppm. It can be sprayed on fruit ears or sprayed. It can promote fruit setting, prolong leaf senescence, and induce callus differentiation to grow young shoots.
10. DA-6 + retardant
Its preparation can be a variety of aqueous solutions, soluble powders, wettable powders, etc. Generally, the retardant is one or more of chlormequat, chlormequat, choline chloride, paclobutrazol or chlortetracycline, which is a fruit setting agent that can be used on tomatoes, grapes, fruit trees, and root and tuber crops. The concentration range of DA-6 is 5-15ppm, and the amount of retardant used varies greatly depending on the type. The use period is generally controlled during the alternation period of vegetative growth and reproductive growth to inhibit vegetative growth and promote reproductive growth to promote fruit setting and increase yield.
11. Chlormequat + p-chlorophenoxyacetic acid (sodium, potassium)
Most of its preparations are water-based or soluble powders, and the main application object is tomatoes. During the alternation period of vegetative and reproductive growth (about three days before flowering), spraying the whole plant of tomatoes with chlormequat 150-200ppm + p-chlorophenoxyacetic acid 25-25ppm can significantly increase fruit setting and yield.
12. Sodium nitrophenolate + 2,4-D
Its preparation can be water-based or soluble powders, which are specially developed for banana elongation. When the banana buds break, spraying the fruit with a solution of appropriate concentration can help increase the fruit index. Generally, the concentration of 2,4-D is controlled at 5-10ppm. Because 2,4-D is also a herbicide, it has strong medicinal properties and is sensitive to temperature, so the concentration cannot be increased at will.
Common misunderstandings in the use of regulators:
Plant growth regulators are mainly exogenous non-nutritional chemicals, which can usually be transmitted to the site of action in the plant body. At very low concentrations, they can promote or inhibit certain links in its life process, so that it can develop in line with human needs.
Because each plant growth regulator has a specific purpose, and the application technology requirements are quite strict, it can only produce specific effects on the target plant under specific application conditions (including external factors).
Often changing the concentration will get the opposite result, for example, it has a promoting effect at a low concentration, but becomes an inhibitory effect at a high concentration. However, in the long-term practice process, many farmers have some obvious misunderstandings when using plant growth regulators, which seriously affect the use effect.
