There are many and varied types of abiotic stress that can impact harvest yield and quality, and over the years, crops have evolved to naturally manage these stresses. However, with climate change presenting new and more extreme challenges, crops need additional support from growers to reinforce these existing mechanisms, which is where biosolutions and specific agronomic management practices play a critical role.
How do crops naturally resist abiotic stress?
Crops have developed various strategies to cope with abiotic stress, enabling them to survive and thrive in challenging environments. However, with the increasing level of abiotic stress experienced on a yearly basis, these natural coping mechanisms are being stretched to the maximum. While plant breeding and new varieties are under development to help better resist these increased stresses, it takes time and it’s not a viable solution for perennial crops, which are already established. To change to a new variety would have significant cost implications for growers. Consequently, there is a rapid increase in the use of agronomic practices such as irrigation, protected cropping to alter climate exposure, and the incorporation of products such as biostimulants into agronomic programs that help reinforce, or enhance, the crops natural coping mechanisms.
Examples of coping mechanisms to resist abiotic stress include:
- Morphology: Modifications to plant structure such as deeper roots to search for water during drought stress, or reduction in leaf size leaves during high UV / heat stress.
- Celled Gene Expression: Modifications to stress gene activity to enable the plant to respond quicker and more effectively to abiotic stress.
- Modifications to plant metabolism and biochemistry to better resist or recover from the negative chemicals such as reactive oxygen species produced during abiotic stress.
Fig 3. Autofluorescence of plant cells, with Control Cells (A) on the top autofluorescing brightly indicating they had been affected by the heat stress. On the bottom (B) the same heat stress was applied. However, Rovensa Next Biostimulant (Phylgreen) was applied before the stress. The lack of autofluorescence in B indicates the cells did not suffer the same intensity of heat stress damage, due to the correct application timing and dose of the biostimulant.
What agronomic practices can I implement to better assist crops in managing abiotic stress?
To best enhance your crop’s ability to cope with abiotic stresses, while minimising yield or quality losses, the above crop coping mechanisms need to be increasingly exploited, leveraged, and enhanced by agronomic management practices. As such, incorporating practices such as irrigation and products such as biostimulants in agronomic management programs alone, or in combination, to reinforce these natural plant processes is becoming the norm.
Within the agronomic management strategies that involve the use of biostimulants, there are three main approaches that can be used:
- Proactive Direct Approach: Try and directly mitigate the effects of combined abiotic stresses abiotic stresses before they occur.
- Reactive Direct Approach: Try and directly mitigate the effects of combined abiotic stresses after they occur.
- Indirect Approach: Try and indirectly mitigate the effects of combined abiotic stresses by positively altering an agronomic aspect that will in turn help the crop to better resist abiotic stresses.
Understanding these different mitigation strategies, how to use them individually, as well as how to combine them is fundamental to achieving the best results as part of an integrated total abiotic stress management program, and across the entire crop growth cycle.
