Abiotic Stress in Plants: Causes, Symptoms, Effects and Effective Management Strategies

I believe as a gardener that sometimes plants don't struggle due to pests or diseases. The growing environment can be the problem at times. Abiotic stress is the stress imposed on plants by environmental factors other than living organisms: high temperatures, deficiency in water or salt, low temperatures, flooding, and inappropriately low/high soil pH or salinity, for example. These are a type of stress originating from the physical and chemical surroundings of the plant as contrasted to the stress of biotic agents such as insects, fungi or bacteria. If stress persists for extended periods, plants could suffer from weak root and shoot growth as well as decreased foliage, flowering and growth. Early detection of abiotic stress in plants is, therefore, vital not only to sustain crop yields but also to develop crop resilience and plant health. We should make sure that the soil, water, temperature or conditions have changed for a plant that appears sick before we plow into the disease.

What are causes of abiotic stress in plants?

Stress factors are frequently related to everyday gardening associated with varying environmental factors. The other abiotic stress factors are extreme temperature, inadequate or excessive irrigation, salty soils, unsuitable soil structure, nutritional deficiency and toxicity, pH, high levels of sun and environmental pollutants. For instance, soil compaction may limit the growth and movement of the roots and high levels of fertilizers can lead to higher salt concentrations around the roots. Likewise, in drought conditions the water and nutrients may be restricted in transport and in water logging, the roots become oxygen-starved. Knowing the most common abiotic stresses can help gardeners make a distinction between stress and pest or disease damage. Improve your crop yields by testing the soil, understanding irrigation patterns and recent weather in order to diagnose the issue before it's too serious to worry about. It's also the point where the importance of microorganisms in agriculture​ comes into play, as a biologically active soil can have a positive effect on the cycling of nutrient stress in plants, the health of the root zone and general growing conditions.

What are types of abiotic stress in plants?

Plants can suffer from different abiotic stresses that will impact crops differently. Heat and cold stress disrupt normal functioning of the body cells, and can cause harm to sensitive body tissues. Both drought and salinity restrict water supply and adversely affect the uptake of water by the roots, and salinity may result in a build-up of ions which is harmful. The waterlogging condition poses a unique problem because it produces deficiency of oxygen around the roots. Nutrient stress is a condition that occurs when the plant has a lack of one or more nutrient, surplus or incompatible nutrient supply due to unsuitable soil conditions. Extremes of soil reaction have also the same effect as a lack of plant available nutrients even if this nutrient is present in the soil itself. Other environmental pollutants, such as heavy metals, may generate further toxicity issues. Abiotic stress factors can negatively impact roots first and then, after longer exposure, their effects are manifested at the growth and yield stage, negatively impacting abiotic stress in crops.

Heat, Drought and Salinity Stress in Plants – The Extreme Stresses

Among the most common environmental challenges faced by gardeners and farmers are heat, water shortage and excessive salts. Heat stress in plants can lead to increased transpiration or the curling and burning of leaves, a decrease in pollen viability and flower drop or reduced fruit setting. Drought stress in plants means that less water will be absorbed by the plant, and may restrict stomatal opening and the movement of nutrients around the plant, which will further prevent photosynthesis. Salt stress in plants is both osmotic and toxic and toxic to plants at very high salt concentrations as well as creating nutrient imbalance. Symptoms include reduced germination, poor growth, and leaf-edge and tip-wilt and weak root systems. The abiotic stress in crops may also combine. If the plant is in a stressed situation because of high temperatures when wet in the soil, it may be dealing with even more stress than if it was in a situation of high temperatures in dry soil. In summary, supporting beneficial microorganisms in agriculture​ can be just one component of a soil and crop-health program, and environmental issue conditions need to be addressed upstream.

How to improve crop yield under abiotic stress?

If stresses are chronic, they cause more than temporary wilt. Abiotic stress in plants throughout the duration can affect physiological roles of photosynthesis, root and shoot growth and nutrient uptake in plants along with enhancing the oxidative stress in plant cells. The plants can decide to close and/or modify their stomata, adapt their metabolism, and allocate energy into protection instead of growth and reproduction. This may manifest itself as delayed flowering, poor fruit or seed sizes, early leaf ageing and lowered quality. When it comes to abiotic stress in crops, severe damage to crop yields can occur in crops. Stress combinations are especially relevant, such as high temperatures which raise the demand for water, and drought which reduces the available water supplies. The prevention or reduction of the abiotic stress is therefore a better approach for gardeners wanting to enhance crops' production when exposed to an abiotic stress while the establishment of a long-term adaptation capacity for the crops should be the next step to be taken when significant stress signs are observed.

Abiotic Stress Management: Practical ways to increase crop resilience

The first step in abiotic stress management of crops is to know what the plant wants and what is happening in the plant's world. Watering should be done efficiently particularly in hot and dry weather, but care must be taken not to over water, otherwise waterlogged roots may result in a lack of oxygen. Mulching could influence soil temperature, water loss and soil organic matter additions could affect soil structure and water holding ability. Gardeners should also keep plants in balanced nutrition and not fertilize on the assumption "if the plant looks weak, then it must need fertilizer. Exposure to environmental extremes can be minimized further by appropriate planting dates, suitability of variety, wind protection, shade if required and adequate drainage. Types of abiotic stress in plants need particular responses hence openness should always be at variance with the stress observed. While it is acceptable to use beneficial fungi and biological inputs in conjunction with these practices, they are not a replacement for appropriate water, soil and nutritional management as part of a comprehensive approach to supporting crop resilience.

Are beneficial microbes useful in coping with abiotic stress in crops?

Bacterias that are beneficial to the plant help improve its resilience

In a healthy growing system, beneficial bacteria can help to maintain biological activity near the roots and play a role in various activities involved in plant growth performance. Some groups of bacteria can increase the availability of nutrients; interact with the roots; facilitate root development; and affect plant defence and signalling responses. For agriculture, there are many beneficial microorganisms which are used in biological products such as Bacillus subtilis. These organisms should be seen as one of the measures of an integrated strategy of crop-health and not as replacements of irrigation or some other form of stress-specific action. In association with proper soil structure, nutrition and moisture management, beneficial bacteria can provide an even better rhizosphere that allows plants to retain better growth during harsh conditions.

Beneficial fungi have a positive impact on plant resilience in several ways

Beneficial Fungi like Trichoderma fungi are used more and more in programmes for sustainable crop management due to their interactions with the plant roots and soil in its vicinity. Trichoderma harzianum can enter the competition with the adjacent microorganisms in the environment, secrete enzymes and metabolites, have interaction with plant roots, induce plant immunity. When integrated within the right biological management program, these interactions are able to help improve root-zone conditions and plant performance. Novobac's biological crop management products based on Trichoderma harzianum are part of this holistic approach. Gardeners must treat these products as part of their management of crop health and not a magic bullet that can completely eliminate drought, heat or salinity stress.

Microbial products have a role to play in the process of abiotic stress management

The full value of microbial products for plants is to be part of a whole farm crop-health program, and not used as a direct reaction to environmental stress. Novobac's Trichoderma products, such as its Trichoderma harzianum solution, and its Bacillus subtilis biological product may be used in combination with appropriate irrigation, balanced nutrition, soil-health practices and other crop-management practices. The goal is to establish a dynamic environment that will benefit plant roots, soil available nutrients and beneficial microorganisms, while interacting directly with root zone environmental stressors. In the real garden, this means that using a microbial product should be used in conjunction with other gardening methods, such as improving drainage in soils with poor water-holding capacity, maintaining moisture in drought conditions or managing salt levels. A single biological input is not going to be sufficiently useful to enable long term plant performance without a multidisciplinary solution at play.

A Gardener's Guide to Building Abiotic Stress in Crops

Creating crops that are resistant to stress begins long before they exhibit clear signs of stress. The first step is to attempt to make sense of the problem and look for possible environmental changes that may have occurred such as different seasons, different irrigation regimes (intensity, duration, frequency), soil moisture conditions or nutrition.

Proper use of beneficial microorganisms can be through proper use of proper biological and soil-management in the garden. However, regular monitoring is necessary since slight leaf colour changes, growth rate, wilting, flowering or development of roots will give valuable clues early on. Those measures are not single measures, but must be integrated with time sensitive measures to be effective abiotic stress management measures. Abiotic stress in plants can be noticed early and right measures can be taken by growers to prevent unnecessary loss of crops and eventually healthy and stress tolerant plants will be increased.

Reference:

• Mastouri, Fatemeh, Thomas Björkman, and Gary E. Harman. "Seed treatment with Trichoderma harzianum alleviates biotic, abiotic, and physiological stresses in germinating seeds and seedlings." Phytopathology 100.11 (2010): 1213-1221.
• Geng, Yueyao, et al. "Positive role of Trichoderma harzianum in increasing plant tolerance to abiotic stresses: a review." Antioxidants 14.7 (2025): 807.