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The Difference Between Plant Hormones And Growth Regulators
Jul 09, 2018

First, plant hormones

Plant hormones have four important properties: endogenous, which is a product of the interior of cells in plant life activities and is widely found in the plant kingdom. Regulatory, regulate and control plant growth and development through its own life activities. Mobility, transportable from the synthetic site of the plant to the site of action. Significantly effective, the content in plants is very small, mostly calculated in micrograms, but can play a significant synergistic effect. There are five major internationally recognized plant hormones: auxin, gibberellin, cytokinin, abscisic acid and ethylene Manhattan fungicide Keywords: broad-spectrum fungicide, rice fungicide, grape fungicide, plant fungicide, soil fungicide , pesticide fungicides, systemic fungicides and other imported fungicides.

1. Auxin

Characteristics of auxin: auxin is indoleacetic acid, referred to as IAA. Since auxin is easily destroyed in plants, plants are generally not treated with indole acetic acid, and plants similar to growth regulators such as indolebutyric acid, naphthaleneacetic acid and the like are often used.

The role of auxin: promote plant elongation, promote rooting, and induce parthenocarpy to control male and female sex. The most basic physiological role of auxin is to promote growth, but it is related to the concentration of auxin, the type of plant and the age of organs and cells. Growth is promoted when the concentration of auxin is low, and growth is inhibited at higher concentrations. Dicotyledons are generally more sensitive than monocots. Root is more sensitive than bud, bud is more sensitive than stem, younger cells are more sensitive than mature cells. Manhattan fungicide Keywords: broad-spectrum fungicide, rice fungicide, grape fungicide, plant fungicide, soil fungicide, pesticide fungicide, systemic Imported fungicides such as fungicides.

2. Gibberellin

Characteristics of gibberellin: Gibberellin is referred to as GA. The formulation solution is susceptible to failure and is suitable for storage in powder form under low temperature drying conditions.

Physiological effects of gibberellin: promote stem and leaf growth, induce bolting and flowering, promote sex differentiation, break dormancy, prevent shedding, induce parthenocarpy, and promote the formation of seedless fruits. Manhattan fungicide Keywords: broad-spectrum fungicide , rice fungicides, grape fungicides, plant fungicides, soil fungicides, pesticide fungicides, systemic fungicides and other imported fungicides.

3. Cytokinin

Characteristics of cytokinins: cytokinin is abbreviated as CTK. It mainly includes kinetin and zeatin. The nature is relatively stable.

The physiological role of cytokinins: promote cell expansion, induce bud differentiation, prevent aging, and promote axillary bud growth.

4. Abscisic acid

Characteristics of abscisic acid: Abscisic acid referred to as ABA. It is a powerful natural inhibitor in plants, with very low content, high activity and great effect.

Physiological effects of abscisic acid: inhibit plant growth, promote shedding, promote dormancy, and regulate stomatal closure.

5. Ethylene

Characteristics of ethylene: Ethylene is referred to as ETH. It is a gaseous hormone that promotes the maturation of tissues and organs. Since ethylene is a gas and is difficult to use, it is generally replaced with its analog, ethephon.

Physiological effects of ethylene: accelerate fruit ripening, promote shedding and senescence, regulate plant growth, and promote flowering.

In the process of plant growth and development, any physiological reaction is not the result of a single hormonal effect, but the result of the interaction of various hormones. The interaction between various hormones is very complicated, sometimes manifested as synergistic effect, sometimes It is characterized by antagonism. Understanding the physiological effects of various hormones on plants, the interactions between hormones, and the relationship with the environment is of great importance in agricultural production.

Second, plant growth regulators

With the research and development of plant hormones, many hormone-active substances have been synthesized in order to control the growth and development of plants more effectively. This is the commonly used plant growth regulator.

1. Growth promoter

Naphthaleneacetic acid (NAA): cutting roots, controlling shoot growth, thinning flowers and fruit, preventing fruit drop before harvest, promoting pineapple flowering, and widely used in rooting for tissue culture.

Indole butyric acid (IBA): The fruit tree is mainly used to promote cutting rooting, causing more and more adventitious roots. It is used for rooting in tissue culture. The acetic acid is widely used and safe, and it is the most important regulator.

2,4-Dichlorophenoxyacetic acid (2,4-D): It can be used as a herbicide at high concentration. It can prevent the falling and fruit formation of tomato and induce the formation of seedless fruits at low concentration. Dedifferentiation of the implant. Manhattan fungicide keywords: broad-spectrum fungicide, rice fungicide, grape fungicide, plant fungicide, soil fungicide, pesticide fungicide, systemic fungicide, etc.

Naphthoxyacetic acid (NOA): promotes cutting rooting and prevents pre-harvest fruit shedding.

6-Benzyladenine (6-BA, BAP): scientific name Green Dan. It can significantly increase the fixing power of grape fruit and fruit stalk, reduce fruit detachment, promote germination of apple side buds, increase branching angle, and be widely used in tissue culture.

Dihydrozeatin: promotes cell division and promotes plant growth.

2. Growth extender and growth inhibitor

Ethylene (CEPA): Ethephon is currently the most widely used regulator in production, and the optimum temperature for its function is 20 ° C - 30 ° C. Promote fruit ripening, inhibit vegetative growth, promote flower bud formation, induce female flower formation and male flower sterility, promote rubber milk secretion, delay flowering, early dormancy, and improve cold resistance.

Chlormequat (CCC): inhibits vegetative growth, thickens plant stems, deepens leaf color, widens and widens leaves, can better photosynthesis, resist lodging, promote flower bud formation, and increase fruit setting.

Triiodobenzoic acid (TIBA): A substance that blocks the transport of auxin. Eliminate the apical advantage, promote axillary bud growth, increase branching, and dwarf plants. Manhattan fungicide keywords: broad-spectrum fungicide, rice fungicide, grape fungicide, plant fungicide, soil fungicide, pesticide fungicide, systemic fungicide, etc.

Bijiu (B9): inhibits the apical dominance, stimulates the growth of new shoots of fruit trees, facilitates flower bud formation, reduces fruit drop before harvest, and promotes fruit coloration. It has been widely used in agricultural production, but some tests have shown that it has toxic side effects on humans and livestock, and it is highly carcinogenic, so it should be banned in agricultural production.

Paclobutrazol (PP333): delays plant vegetative growth and promotes reproductive growth.

Maleic hydrazide (MH chlorophyll): inhibits stem elongation, prevents onion, potato, garlic, etc. from sprouting during storage and inhibits tobacco axillary bud growth (Figure 12-17). However, maleic hydrazide may cause cancer and distort the chromosome of the animal, and it is preferable to use it for food plants.

Shaper (morphe): inhibits stem elongation and seed germination, and promotes seedless fruits in crops such as grapes and tomatoes.