Guttation ensures the survival of small-sized plants by getting rid of excessive moisture content. Moreover, this biological process usually occurs to control the entry and exit of water, which is essential for the transport of nutrients and chemical reactions.
What is the Main Cause of Guttation in Plants? The main cause of guttation in plants is the development of pressure in roots when they absorb moisture from the soil. They push sap upward to the stem in the form of xylem sap when they absorb water beyond their capacity to hold. Then, hydathodes release water out of the leaves and stem to get rid of xylem saps containing toxins, minerals, metals, microbes, etc. Furthermore, high humidity in the environment, overwatering, and a lesser rate of evaporation allow guttation at night.
The plant structure is made of strong tissues that do not burst when the fluid pressure increases inside them. However, the veins of the leaf are soft that can easily get damaged.
So, they have found a safe mechanism of guttation to allow passage for water to get out of the pores.
What is Guttation in Plants?
It is a process of removing extra water from plants through their leaves or stems. It occurs when there is a lot of moisture in the soil and helps them survive.
They expel the excess fluids out of their bodies to maintain their ideal level. Many people confuse this term with transpiration, but the pores for removal and time of expelling water vary in them.
Transpiration occurs in the daytime through stomatal openings and releases water droplets on the surface of leaves. At the same time, it occurs in the dark when there is no sunlight.
What Causes Guttation in Plants?
Many reasons account for this biological process to occur in plants of a particular age and type.
Its reasons include the buildup of pressure in the root system and excess moisture content in the soil.
Pressure in roots
All plants need water for crucial processes, including metabolism and reproduction. In addition, their breathing capabilities are affected by the excess fluid as it limits the supply of oxygen.
The roots absorb water when the soil contains enough moisture. Therefore, they have to devise some strategies to remove the extra amount of fluids entering inside them.
Excess water builds pressure inside roots, pushing xylem sap upward to the stem. Therefore, it reaches the stem, leaves the region, and tries to get out of the pores.
Moreover, some of them remove the extra fluid to moisten the dry soil by dropping the water drops on the ground. A moist soil ensures better transport of nutrients to roots.
They cannot remove water from their bodies by sweating when there is high humidity in the environment.
In addition, humid conditions initiate this process when there is cold outside.
However, low humidity and dry weather promote water loss by different means and reduce the need for guttation.
There is better evaporation during warm weather when the temperature is high, and excess water releases out through their bodies after sweating.
This evaporation occurs directly from the soil, which contains a lot of moisture, or through the leaves and stems. They need to evaporate to remove the xylem sap containing toxins.
Overwatering of soil
The pressure in the roots increases whenever you overwater the plants. The availability of moisture increases in the roots, which try to absorb the maximum quantity of nutrients.
When excess water enters the roots or exceeds the normal range, it begins to push upward towards the stem.
Therefore, it removes extra water from their body.
Is Guttation Essential for Plants?
You can consider guttation as a survival mechanism of plants that helps protect them from fungal infections or rot.
The presence of moisture closer to the roots promotes fungal growth that can damage the whole structure.
So, they allow water or xylem sap to move up to the stem to release it from leaf blades or ends. It reduces the moisture in the roots section and protects them from infection.
Moreover, it helps maintain the balance of fluids by removing the excess water in the form of drops through small pores in the leaf or stem.
How do plants remove water during guttation?
Plants have a special guttation process that works through hydathodes on the surface of leaves and stems.
Almost 3 to 5 % of water comes out through this process, while transpiration plays a crucial role in removing a significant percentage.
These nozzle-like pores, which look like stomata due to their bean-shaped structure, expel extra fluids from the plant’s body and place them on the leaf blades.
These fine pores are present on leaf tips or blades area and at the junction points of stems and leaves. Furthermore, accumulated drops can dry out on the leaf surface and fall down.
Is guttation in plants harmful?
Guttation is a common process of releasing an excess of water that occurs naturally.
It is beneficial for the plant itself as it helps get rid of root pressure and toxins in the dark when transpiration cannot control the operations.
However, the presence of deposits on the leaf surface can be harmful to other insects. Likewise, bees try to reach the leaf blades’ sugary components of released sap.
It can be dangerous for bees to drink the liquid from leaves after a spray of pesticides. Accordingly, it can promote infections that can be fungal as moisture attracts fungus to attack it.
These chemicals re-enter the soil and roots when the drops fall. The xylem sap can also collect all the deterrents prayed on seeds to protect them from infection.
The hydathodes releasing water remain open, helping fungus grow by providing a continuous source of moisture.
Moreover, these drops can be harmful when you are giving a high dose of fertilizers that are harsh in nature.
This is because the minerals come up to the leaves through sap water and accumulate on the leaves.
It leads to browning and burning of the leaves due to exposure to soft tissues with harsh chemicals. This process indicates good health and that all the systems are working correctly.
What type of chemicals do plants release during guttation?
In guttation, xylem sap gets out of the pores of petals, leaves, and stems in the form of water.
A major percentage of the xylem sap consists of water, but a small number of minerals, microbes, and other compounds are also present.
It contains multiple types of nutrients, including proteins or amino acids and sugars in the form of glucose.
In addition, many microorganisms, including fungi, viruses, and bacteria, are also part of the sap that makes these drops harmful.
Some metals like iron, potassium, sodium, calcium, and minerals are present in the watery fluid.
Furthermore, it contains the contaminants and toxins released from the leaves to ensure protection. The amount and nature of the exudate depend on age and type of plant.
Moreover, environmental conditions like humidity, temperature, and time determine its composition.
Why does guttation occur at night?
Plants have a special mechanism for releasing extra water from their bodies day and night. The task of removal of xylem sap is divided between stomata and hydathodes.
In the daytime, transpiration controls and maintains the balance of fluids. In contrast, guttation helps remove water at night due to the high humidity.
There is no transpiration due to closed stomata at night, so this process starts when root pressure increases.
Therefore, it works when the transpiration process stops that only occurs in the dark when there is no sunlight. Many people consider dew drops as the drops released after removing xylem sap.
However, there is a difference, as dew drops are condensed drops of moisture present in the air.
Does guttation occur in all plants at night?
The guttation process occurs only in small-sized plants with a maximum length of 2 to 3 feet. These include strawberries, grass, fruit trees, tomatoes, and many others.
It occurs only in herbaceous plants having a vascular system, and no terrestrial trees are there that can remove water through this process.
It is difficult for large-sized trees to maintain pressure in the roots, so they cannot push the liquid upward. You can observe the drops of xylem sap with sawtooth-like leaf edges.
In addition, some orchard fruits, vegetables, and ornamental trees, including rose, cucumber, potato, cabbage, maize, etc.
In the early morning, you can see drops of water on different types of grasses, bamboo, and banana tree. It also occurs in houseplants, flowers, and food crops.
However, there is no such release of xylem sap in taller trees, conifers, and a few plants belonging to the citrus family of fruits.
When does guttation occur in plants?
The guttation process occurs at night when the transpiration process is not working to provide sufficient water from plants to breathe.
In contrast, transpiration manages all the tasks in the morning that helps evaporation of water in warm weather.
Moreover, you can see drops or exudates on the stems and leaf edges in the early morning that are not dew drops.
So, late night and early morning are the perfect time to release toxic compounds through fluids when the soil has enough moisture to absorb nutrients and conduct xylem sap.
You can see multiple drops of water on the leaf edges or blades and stems when you visit the garden in the morning.