Comparison of three plant growth regulators: indoleacetic acid VS indolebutyric acid VS naphthaleneacetic acid, which one do you choose?
a. Indoleacetic acid
Indoleacetic acid can be used to promote the germination of rice, peanuts, cotton and tung seeds, and promote the rooting of cuttings of plum trees, apple trees, pine trees, grapes, mulberry trees, poplar trees, metasequoia, spirea, potatoes, sweet potatoes, Chinese kiwifruit, etc. At the same time, it can also promote the growth of potatoes, corn, barley, broad beans, beets, radishes and other beans, and increase yields.
Indoleacetic acid is easily decomposed in plants, affecting its efficacy. To inhibit its degradation, polyphenols such as catechol, catechol, caffeic acid, quercetin, etc. can be added to the indoleacetic acid solution to inhibit the activity of indoleacetic acid oxidase in plants.
Indoleacetic acid is easily decomposed by light and is easily soluble in organic solvents such as anhydrous ethanol, acetone, ethyl acetate, and dichloroethane, but insoluble in water. When preparing the solution, it should be dissolved with a small amount of alkali solution (such as 1 mol/kg NaOH or KOH) to form sodium salt or potassium salt, and then diluted with water to the use concentration. Indoleacetic acid crystals can also be dissolved in 95% ethanol to form an approximately 20% ethanol solution, and then the ethanol solution is slowly poured into a certain amount of water and then fixed to volume. Do not pour water into the ethanol solution. The prepared solution is easily decomposed when exposed to light or heated, and should be stored away from light.
Naphthaleneacetic acid is a broad-spectrum auxin plant growth regulator that has the action characteristics and physiological functions of endogenous auxin indoleacetic acid. It can promote cell division and expansion, promote the formation of plant roots and induce adventitious roots, promote seed and cutting rooting, and promote rooting of Solanaceae plants. In the field of vegetables and fruits, it can significantly promote the enlargement of fruits and tubers, so it is often used as a growth regulator. Naphthaleneacetic acid can also change the ratio of male and female flowers, increase the flowering and fruiting rate, prevent the falling of flowers and fruits, thereby increasing the yield, improving the quality, and promoting the vigorous growth and robustness of the plants. At the same time, it can also enhance the stress resistance of crops, such as cold resistance, drought resistance, waterlogging resistance, disease resistance and salt and alkali resistance.
High concentrations of naphthaleneacetic acid will inhibit growth. In production, it is often used as a rooting agent for cuttings, an anti-fruit drop agent, a fruit setting agent and a flowering regulator. When used as a fruit setting or anti-fruit drop agent, the concentration of naphthaleneacetic acid should not be too high. Increasing the concentration by 10mg/kg may have a counter-effect, because high concentrations of auxins promote the production of ethylene in plants. When used as a rooting agent, although the rooting effect is good when used alone, the growth of seedlings may not be ideal. Therefore, it is recommended to mix it with indoleacetic acid or other rooting regulators to improve the effect. The spraying amount of melon and fruit plants should be sprayed evenly on the leaves. The spraying liquid is about 50kg per mu for field crops and 75~125kg for fruit trees.
When applying the pesticide, special attention should be paid to spray only the flowers, and each flower should be sprayed only once to avoid touching the leaves and unopened buds. The substance is stable in nature but is easy to deliquesce and change color when exposed to light. It should be stored away from light. It forms salts when it meets alkali and is difficult to dissolve in cold water. It needs to be dissolved in boiling water.
When using naphthaleneacetic acid, be sure to follow the concentration requirements in the instructions and do not increase the concentration at will to avoid causing pesticide damage to the plant. Mild pesticide damage may cause the flowers and young fruits to fall off their leaves, which has little effect on plant growth; severe pesticide damage is manifested as leaf shrinkage, petiole flipping, leaf shedding, and rapid ripening and shedding of fruits. For seed soaking pesticide damage, the mildest is less roots and deformed roots, and the severest is no rooting and no seedlings. Most of the pesticide damage of naphthaleneacetic acid does not affect the next crop, but some crops may react. For example, figs may be damaged when the concentration exceeds 50mg/kg.
c. Indolebutyric acid
Indolebutyric acid is stable under acidic conditions and forms salts in alkaline environments. It will gradually decompose under light and can be rapidly degraded in the soil. Its mechanism of action is similar to that of indoleacetic acid. It has auxin activity. After being absorbed by plants, it is not easily transported in the body and often stays in the treated area. Therefore, it is mainly used to promote rooting of cuttings. It can induce the formation of rhizogenes, promote cell division, and is conducive to the growth of new roots and the differentiation of the vascular system. Its effect in promoting the formation of adventitious roots of cuttings is better than that of indoleacetic acid. Indolebutyric acid can induce cuttings to grow thin, sparse, and multi-branched roots, while naphthaleneacetic acid can induce thick, fleshy, multi-branched roots. Therefore, the rooting effect is better when indolebutyric acid is mixed with naphthaleneacetic acid.
It is often used for root transplanting and hardwood cuttings of woody and herbaceous plants, which can accelerate root growth and increase the rooting percentage of plants. It can also be used for soaking and mixing plant seeds to improve germination rate and survival rate. When dipping roots for transplanting, the concentration used is 10~20mg/kg for herbaceous plants and 50mg/kg for woody plants; the dipping concentration for cuttings is 50~100mg/kg; the concentration for seed soaking and seed dressing is 100mg/kg for woody plants and 10~20mg/kg for herbaceous plants.
When using indolebutyric acid to treat cuttings, avoid the liquid from contaminating the leaves and heart leaves. The concentration used should be strictly controlled according to different crops. 0.06% indolebutyric acid solution is harmful to figs. Since indolebutyric acid is insoluble in water, it must be dissolved in ethanol before use, and then diluted with water to the required concentration.
Indoleacetic acid is easily decomposed by indoleacetic acid oxidase in plants, and is also easily damaged by strong light, while indolebutyric acid is not easily decomposed by oxidase. Compared with naphthaleneacetic acid, a slightly higher concentration of naphthaleneacetic acid may damage branches, while indolebutyric acid is not easily transmitted and only stays in the treated area, so it is safer to use.
The above information is for reference only. Please read the product manual carefully before use and follow the guidance of professionals.
