Apr. 5, 2018
Abiotic stress: the most harmful factor for the growth and productivity of crops
Stressful conditions related to non-living factors, widely known as abiotic stress, are becoming a first order and patent problematic in today’s farming. Nutrition and sanitary state have been for a long time farmer’s main concern. Today, adverse environmental conditions, which strongly limit produce quality and yield, are becoming an increasing disquiet.
In spite of still being a recent topic, the research community has sorted abiotic stress as the most harmful factor for the growth and productivity of crops worldwide (Gao et al, 2007). Furthermore, these factors are in most cases taking place in combination with other biotic or abiotic stress factors, resulting in the most detrimental scenario in current agriculture (Mittler, 2009). Sadly, it is expected that abiotic stress pressure will depress agricultural yields in most countries over the next few decades (Cline W., 2007; Müller et al., 2009).
Identification of the causes of abiotic stress for the definition of a suitable strategy
The main characteristic of abiotic stress is that we cannot (or hardly) avoid its occurrence. Depending on the source of the adverse effects, they can be sorted in two general kinds: permanent and occasional stress.
• The first group gathers all those constraints that are always present in our crops, like salinity, strong wind, radiation exposition, etc.
• While the second one refers to those unexpected events that subject crops to sub-optimal or lethal conditions during a short period of time, such as drought, frost, floods, heatwaves, etc.
The event scenario is being worsened by the climatic alteration suffered around the world. When a farmer is asked about the evolution of weather conditions, they usually claim unnatural and unexpected events. In other words, “strange weather is becoming stranger”. In fact, renowned organizations such as FAO or NASA have remarked completely unexpected events across the planet in the last years.
How to face these situations is the key for increasing crop performance and farmer profitability. In the case of permanent stress conditions, crop selection and plant adaptation becomes crucial. In the case of occasional stress situations, preparing the plant for enduring stressful events turns out to be the best strategy. However, achieving the latter is not always easy.
Preventing the effects of abiotic stress: forecasting, early stress detection and preventive applications of biostimulants
Forecasting and early stress detection turn out to be a crucial task in our current paradigm. Fortunately, weather forecasts have been refined with increased accuracy in recent years and the development of new technologies in sensoring have become a key tool. Real time monitoring of field parameters, combined with official weather forecasts, are today a reality that allow farmers to better predict stress occurrence and pest/disease incidence.
However, abiotic stress detection is not always an easy task, especially under sub-optimal conditions, or when stress is starting. In these scenarios, stress triggers the plant’s physiological and metabolic response in order to adapt itself to the new conditions. This usually involves a high consumption of energy at the expense of growth, yield or quality (figure 1). Yet, some of these changes are not visible to human eye, providing often the sensation that nothing wrong is going on with the crops. Unfortunately, stress is almost always present in one way or another in our crops.
Even if stress detection can be a difficult task that cannot always be implemented in the field, new technologies have been developed to detect alterations in plants and help farmers and technicians to early detect stress conditions, such as thermal imaging (figure 2), NDVI, IRGA equipment, leaf sensors, etc.
Successful results in stress prevention cannot be understood as isolated elements: weather, soil and plants are a synergic whole that cannot be understood separately. Just by the global interpretation and monitoring of all these elements together, this complex system can be figured out, taking into account such different management components as nutrition, soil properties, weather conditions and plant phenological stage. We need to read the signs and listen to our crops.
Unfortunately, abiotic stress detection is not enough by itself. Plants need to be prepared for the upcoming stressful events and biostimulants, amongst other benefits, are able to prepare the plant to better conquer stress periods. Tradecorp’s in depth research has proven that preventive applications of certain biostimulants can effectively prepare the plant for stress endurance. Because of the detrimental use of energy and risk involved in these situations, preventive applications have been shown to increase the plant’s performance rather than curative actions once stress has occurred (or is taking place).
Priming effect biostimulants: preparing plants for stress endurance
In terms of preventive action, Phylgreen, Tradecorp’s gentle, pure extract from the seaweed Ascophyllum nodosum, is a flagship product. Intensive research by Queen’s University Belfast claims that, the preserved active ingredients from Ascophyllum nodosum present in the product, are able to alter the plant’s genetic expression in terms of stress response. When “primed” by the product, the plant is set under a systemic “alert state” that makes it more “aware” and ready to respond under stress conditions. Thanks to this alteration, the stimulation of the primary metabolism and the accumulation of compatible osmolytes and hydroxyl radicals (ROS) quenchers, the crop is not only able to increase its chances of survival, but also to avoid a dramatic drop of yield and quality.
The combination of weather forecast and the stress monitoring cannot be understood without the implementation of preventive actions, such as Phylgreen. This strategy requires:
-To detect the most stressful periods and their harmful effect on the plant.
-To select the right moment and dose for application.
-To ensure that the most critical crop stages have been prevented from stress.
Forecast, detection and Phylgreen: a leading option to face the environmental challenge that agriculture means today.