Plants are sessile organisms, meaning that they are firmly rooted or connected to a soil and climate environment from which they cannot escape. This keeps them constantly interacting with a hostile environment throughout their life cycle. There are numerous biological, physical and chemical factors that constantly affect plants in various ways, either positively or negatively. These factors include extremely high or low temperatures, excess or lack of water, high salt content, presence of heavy metals, ultraviolet radiation, among others (He et al., 2018).
Stress is used to describe alterations in the physiological behavior, development, or functions of a plant that may result in irreversible damage to its entire system. These types of stress are divided into “biotic” and “abiotic” depending on whether the cause of the alteration comes from living organisms such as fungi, bacteria, viruses, and insects, or from non-living factors such as climate and mineral elements (Pareek et al., 2010). Abiotic stressors are considered a threat to agriculture and ecosystems, which can have a negative impact on crop yields (Wang et al., 2003). It is estimated that environmental factors can limit agricultural production, even reducing yield by up to 70%, which has important economic, social and food security implications worldwide (Boyer, 1982).
According to FAO reports, approximately 96.51 TP3T of global arable land is affected by abiotic stress factors. This is divided into 261 TP3T of agricultural land with problems related to excess or lack of water, another 261 TP3T with problems of extremely low temperatures, and the remainder suffering from problems related to salinity or lack of nutrients (FAO, 2007).
Plant responses to environmental conditions are complex and dynamic, and depend on the type of stress, its intensity, and the interaction with other abiotic factors. Plants may respond elastically (reversibly), plastically (irreversibly), or ultimately may die depending on the severity of the stress (Cramer et al., 2011). When a plant is faced with changing environmental conditions, it uses mechanisms to detect these changes and responds in different ways, depending on the type and intensity of the stress. These responses are divided into four main phases: alarm, resistance, exhaustion and regeneration (Mosa et al., 2017). During the alarm phase, the plant recognises the change in optimal growth conditions and adjusts its activity to respond to the stress. If the stress persists, the plant enters the resistance phase, where it focuses on repairing and protecting its structures. If the stress continues to increase, the plant may enter the exhaustion phase, where its mitigation mechanisms are no longer sufficient, which can lead to programmed senescence and ultimately death. However, if the stress decreases or ceases, the plant may enter the regeneration phase and begin to repair the damage (Lichtenthaler, 1998).
In the context of post-harvest, summer in Chile is characterized by high temperatures, intense radiation and water shortages in the main fruit and crop producing areas. This can unbalance and reduce the productivity of crops that have not yet been harvested, as well as negatively affect floral differentiation and the accumulation of reserves for the following agricultural season. An example of this summer stress is the appearance of double fruits in cherry crops, which negatively affects productivity and fruit development in the following season (Figure 1).
To mitigate these effects of summer stress, it is crucial to maintain adequate water management in the crop. However, it is mandatory to complement irrigation with tools that stimulate optimal plant functioning to maximize stress tolerance, given that the combination of high temperature, radiation and water demand during the summer generates an extreme stress condition.
What tools can we use?
Our strategy considers the combination of Aquaret, Algrow and ReZist products, a triad that seeks to maintain humidity for longer and a more comfortable and resilient plant during the summer months.
What is the role of each one?
AquaRet: Adjuvant polymer formulated to reduce water evaporation and conserve soil profile moisture for longer, maintaining the plant's water status better between each irrigation event.
Algrow: Seaweed extract “Ascophyllum nodosum"Designed to alleviate abiotic stress and enhance plant development during critical phenological stages.
ReZist: Biostimulant designed to activate mechanisms of tolerance to stress caused by high temperatures and water deficit, promoting the activation of antioxidant enzymes and accumulation of metabolites that allow maintaining an adequate osmotic potential in the plant, maintaining a higher metabolic rate.
By using the Stoller strategy we will be able to observe an improvement in water status, photosynthesis and stomatal conductance (Table 1 and Figure 2), allowing the plant to continue its processes (floral differentiation and/or fruit growth depending on the type of crop) in a more resilient environment and with a lower stress load.
As the Stoller Group, we are committed to continuing to generate, validate and implement solutions to the problems of agricultural production worldwide.
