Fundamental Plant Processes

For growth to occur, plants need sunlight, water, and nutrients. To optimize growth and nutrition we must look at, and understand how, a plant works.

March 16, 2022
3 mins

Growth = photosynthesis − respiration

Photosynthesis is a set of processes inside the green parts of plants, where they produce energy in the form of sugars and oxygen. The Processes are influenced by daylight.

Tip: Always try to maximise photosynthesis – it is key to good plant growth

 

Growth

Simply put, the difference between photosynthesis and respiration is growth. If a plant is able to produce more energy during photosynthesis than it consumes during respiration, it will grow. Growth is an increase in dry matter (mass). 

Photosynthesis

A quick recap: Photosynthesis is the name for the complex reaction which plants use to turn energy from the sun into sugars. In other words, the plant takes carbon dioxide from the air and water from the soil and combines them to form carbohydrates (sugar). Oxygen is released as a by-product. Photosynthesis is dependent on temperature and light exposure, so it only occurs during the day. 

Respiration

Plants (like humans) burn sugars and produce carbon dioxide in respiration. In addition to sugars, respiration also requires oxygen and water. Unlike photosynthesis, respiration does not require light: it occurs during the day and the night. 

Plant design: essential for optimal growth 

Leaf functions

Leaves contain chlorophyll and chloroplast, two important components used in the production of sugars in photosynthesis. Leaves exchange gasses via their stomata—consumption of CO2 minus production of O2. Evaporation occurs via the leaves as well. Evaporation is needed for the plant’s cooling down processes and it is a pulling force, enabling the transport of water and nutrients within the plant.

The stem

The plant’s stem carries water and nutrients, and provides strength, growth, and cell division. 

The roots

Plant roots absorb water and nutrients. But be aware that the actual absorption of water and nutrients happens only through the young and active root hairs. The root system itself pushes water upward in the plant, drains out waste substances, and provides stability in the soil. 

Creating efficient nutrient transport 

Soil nutrients come in three basic categories: macro, meso, and micro elements. For growth to occur, there has to be a proper balance between these categories.  

ElementRatio in plant tissue
Molybdenunm1
Copper100
Manganese1000
Calcium100,000
Nitrogen1,000,000

Plants absorb nutrients in the form of nutrient elements. Plants can only absorb elements that are dissolved in water. 

Water is the essential transporter that plays a key role in photosynthesis and plant nutrition. Without water, there can be no growth.
Water could be considered as the plant’s most essential mineral. It plays a key role in evaporation and transpiration: it cools down leaf temperature building strong stems and leaves the absorption and transport of nutrients and minerals. 

Three ways we can help the plant

  1. Stimulate the continual rejuvenation of the root system. Water and nutrients only reach the plant via its root hairs. You can boost root growth by applying a high-phosphorus fertilizer.
  2. Only use perfectly soluble fertilizers, as they’ll have the best effect and will help to maintain low EC levels in the growing medium.
  3. Adjust irrigation to the plant’s water needs at any given moment: 
    • Ensure constant moisture levels in pots and containers and don’t let them dry out: hydrophobic areas can be difficult to penetrate, inhibiting the plant’s ability to take up nutrients and grow. A wetting agent can help to overcome water management issues and reduce watering frequency. 
    • Create the best possible climatic conditions around the plant to minimize evaporation. More evaporation means more watering is required, so take care when plants are in direct sunlight or subject to dry east winds. The less evaporation, the more energy the plant can put into growth.