Plant Growth and Development – An Introduction

Plant growth regulators are chemical compounds that control all aspects of plant development and growth. Phytohormones and plant growth hormones are some of the other names for it. They have a significant impact on physiological processes such as plant growth, development, and mobility. Plant growth regulators are Plant growth regulators and Inhibitors of plant development. Plant growth promoters include auxins, gibberellins, and cytokinins, while plant growth inhibitors include Abscisic acid and ethylene. Ethylene can be classified as either a plant promoter or a plant inhibitor.

What are Plant Growth Regulators?

Plant growth regulators are chemical compounds that affect plant cell development and differentiation. Chemical messengers assist cells in communicating with one another. Plant hormones are another name for these substances.PGRs (plant growth regulators) are a type of chemical. Their absence causes stunted development, leaf discoloration, and the loss of fruiting bodies, all of which result in lower crop yields. Nutrients come in a range of ratios, which may or may not be appropriate for a particular crop. The active components are usually viscous and contain a lot of solids. As a result, they are very likely to be affected by sedimentation and other destabilizing processes. As a result, selecting the right dispersant is critical to achieving a good formulation.

For the best quality plant growth regulators products please visit Geeken Chemicals.

Following are types of Micronutrient

MicronutrientA micronutrient’s rolePlants lacking vital micronutrients
Iron In plants, iron aids biological processes and cell growth. Iron is a component of enzymes and is required for photosynthesis and chlorophyll production.Between the veins of the young leaves, chlorosis has developed.
BoronBoron is necessary for sugar transfer, cell division, and amino acid production, and it improves flowering flowers and generates a uniform ripening process.Chlorosis causes leaf deformation and discoloration areas.
ManganeseManganese is required for photosynthesis, chloroplast formation, as a cofactor in numerous plant processes, and as an enzyme activator.Between the veins of the young leaves, there is chlorosis.
CopperCopper activates photosynthesis-related enzymes.Overall chlorosis, leaf tip twisting, and turgor loss in immature leaves are all signs of chlorosis.
MolybdenumMolybdenum is required for the growth of leaves and the avoidance of disease in plants, as well as for nitrogen metabolism, which is required for legume nitrogen fixation.The oldest leaves have chlorosis.
ZincIt is necessary for plant hormone balance and auxin activity, as well as for growth, cell division, and grain husk development.Young leaf growth is slower than usual.

Types of Plant Growth

  • Primary and Secondary Growth-Meristematic cells found at the root and shoot apices divide mitotically, lengthening the plant’s body. Primary growth is the term for this type of development.
  • Unlimited Growth-The term “unlimited growth” refers to a plant’s continuous development from germination to death.
  • Limited Growth-After reaching a particular size, the plant parts stop developing in this stage.
  • Vegetative Growth-Except for the flowers, it entails the creation of stems, leaves, and branches.
  • Reproductive Growth-At this stage of development, flowering takes place.

Factors Affecting Plant Growth

They are as follows:

  • Light-The movement of stomata, chlorophyll production, photosynthesis, and other physiological variables are all influenced by the intensity, quality, and duration of light.
  • Water-Water is essential for plants to survive. Water makes up roughly 90% of the plant’s body. In the lack of water, plants become stressed and perish. The plant collects and transfers the nutrients along with the water it absorbs from the soil.
  • Temperature-Temperature has a big impact on plant growth. High temperatures hasten the processes of transpiration, photosynthesis, and germination. Low temperatures, on the other hand, stifle plant growth.
  • Nutrients-Plants, like humans, require adequate nutrition for their growth and development. Plants require macronutrients such as nitrogen, potassium, calcium, magnesium, sulphur, and phosphorus. Iron, copper, and other micronutrients are among them. Plants that are deficient in certain nutrients are more susceptible to a variety of illnesses.

Discovery of Plant Growth Regulators

Charles Darwin and his son, Francis Darwin, were the first to uncover significant plant growth regulators. They determined the presence of a transmittable component that influences the growth of canary grass towards the light after a series of trials. F.W. Went later isolated the transmissible molecule, which we now know as auxin. Many scientists identified and isolated various plant growth regulators later on. E. Kurosawa discovered gibberellins, also known as gibberellic acid, in uninfected rice seedlings.

Characteristics of Plant Growth Regulators

Plants require various chemical components to control their growth and development since they require oxygen, water, sunlight, and nutrients to develop and thrive. These are simple organic molecules with a variety of chemical make-ups. Phytohormones, plant growth chemicals, and plant growth hormones are other names for them. They have the ability to both accelerate and slow plant growth.

Auxin, cytokinin, gibberellins, and abscisic acid are only a few examples of plant growth regulators. Auxin, gibberellins (GAs), cytokinins, abscisic acid (ABA), and ethylene are the five types of plant hormones. A variety of natural and artificial derivative chemicals that act as plant growth regulators are also available. The features of plant growth hormones, also known as plant growth regulators, are as follows:

  1. Cell differentiation and elongation.
  2. The development of leaves, flowers, and stems
  3. The wilting of the leaves.
  4. Fruit ripening.
  5. Seed dormancy, and so on.

Types of Plant Growth Regulators

The following are examples of plant growth hormones or regulators:

  1. Plant Growth Promoters include Auxins, Gibberellins, and Cytokinins, to name a few.
  2. Plant Growth Inhibitors, Abscisic acid is an inhibitor of plant development. It regulates organ size as well as stomatal closure. It also aids in the dormancy of buds and seeds. Other examples of such inhibitors are Ethylene.


Auxin was the first phytohormone identified. It was discovered by biologist Charles Darwin. Cell elongation, root growth, and shoot growth are all aided by it. The plant hormones example is auxin. Plant hormones can be found in both natural and synthetic forms. Natural sources of indole-3-acetic acid and indole butyric acid exist, whereas synthetic sources of naphthalene acetic acid and 2, 4-dichlorophenoxyacetic acid exist.

Functions of  Auxins

  • Make it easier for plants to blossom.
  • Gardeners use it to keep weeds out of their lawns.
  • Assists in the establishment of roots in stem cuttings. Preventing leaves and fruits from falling off at an early stage.
  • Assists in cell division and regulates xylem differentiation.
  • Encourage spontaneous abscission (detachment) of elder leaves and fruits.
  • The tip of the root and shoot produces them


Gibberellins are a large chemical family whose structure is ent-gibberellin. The first Gibberellin discovered was Gibberellic acid. They are acidic and are labeled as GA1, GA2, GA3, and so on.

  • Involved in the growth of leaves.
  • Break the dormancy of the bud and seed.
  • Encourage cabbage and beet bolting.
  • Enhance the form of fruits such as apples by allowing them to elongate.
  • Used as a spraying agent to boost sugarcane production by lengthening the stem.
  • Increases crop productivity by increasing the height of plants like sugarcane and the length of the axis of plants like grape stems.
  • Gibberellins are naturally acidic.
  •  It also delays the onset of senescence. 


They aid in the production of new leaves, lateral branch growth, and the formation of chloroplasts in leaves, among other things. They aid in the reduction of apical dominance and the postponement of leaf aging. Cytokinins stimulate the mitotic process, which aids cell division. They also aid in the growth of shoots, buds, and fruit and seed development.

Functions of Cytokinins

  1. Break the dormancy of the buds and seeds.
  2. Encourages the development of the lateral bud.
  3. Promotes apical dominance and cell division.
  4. Induces cell division in mature tissues in tissue culture.
  5. Encourage the production of accidental shoots and the growth of lateral shoots.
  6. Helps to prolong leaf senescence by promoting nutrient mobilisation.
  7. Assists in delaying the ageing (senescence) process in fresh leaf crops such as cabbage and lettuce.
  8. Used in combination with auxin to encourage the development of shoots and roots, depending on the ratio.

Abscisic acid

It’s a growth inhibitor that’s been around since the 1960s. It was first referred to as dormant. Abscisin-II, a later chemical, was found and is now known as abscisic acid. It’s also known as the stress hormone since it aids plant tolerance to a variety of stressors. Functions of Abscisic acid:

  1. Stimulates the epidermis’ stomata to close.
  2. Assists in seed maturation and development.
  3. It has a role in abscission and dormancy regulation.
  4. Induces seed dormancy and aids in the resistance to desiccation and other harmful growth stimuli.


Most plant organs, including ripening fruits and aging tissues, synthesize ethylene, a basic, gaseous plant growth regulator. It’s an unsaturated hydrocarbon with double covalent connections between carbon atoms and next to them. As a result, we can understand how significant plant hormones or plant growth regulators are in plant growth and development.

 Functions of Ethylene

  1. Encourage the mango tree to bloom.
  2. Encourages potato tuber sprouting.
  3. Brings seeds and buds out of their dormancy.
  4. Increases the pace of fruit ripening respiration.
  5. Used to encourage the flow of latex from rubber trees.
  6. Helps both flowers and leaves to senescence and abscission.
  7. Tomatoes and citrus fruits, for example.
  8. Affects seedling horizontal development and axis swelling in dicot seedlings.
  9. Promotes the production and proliferation of root hairs, allowing the plant to expand its surface area for absorption.

Plant Growth Regulators: Safe?

We may be too late in the season to grow our own vegetables and flowers instead of purchasing nursery stock. It’s also a good reason to buy nursery stock from a reputable organic dealer if we don’t want to raise our own plants. PGR has come to refer to a wide range of items, not all of which are potentially dangerous.

However, a PGR is a spray or chemical used to treat seed or developing plants that, by cellular mutation, makes the plant more appealing in some way, usually to the seller rather than the buyer. Planet Natural offers a wide range of natural and organic fertilizers that promote plant growth, blooms, and abundant harvests. They are frequently classified and controlled as insecticides, however, they primarily address concerns with growth, flowering, and fruiting. Some are organic chemicals, particularly those used to stimulate roots.

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