Frosts, which are very common in the winter season, are an important aspect that should be taken into account when choosing the crops and variety we want to produce, as well as its location. As we will see below, the problem comes in spring, with temperature moderation. In spring, plants do not require as much cold as in winter, but although low temperatures are not expected at this season, sometimes the generally known as late or spring frosts occur. These frosts, due to climate change, are becoming more and more common.
Once the crops come out of the winter plant dormancy, and begin to have movement in their tissues, they become more sensitive to these frosts, which causally cause greater damage to the plant. This damage is not only due to the drop in temperature, but also to the ice formation within cells. Approximately 50-90% of the fresh content of plants is water, so when temperatures drop below 0 ?C, they begin to freeze and increase their volume, with the consequent fracture of plant tissues. This tissue fracture and its consequences are known as intracellular frost. The formation of intracellular ice causes a “mechanical fracture of the protoplasmic structure”, according to authors such as Levitt (1980).
Similarly, extracellular frost can also occur, when ice forms on the surface of the culture. This causes an outflow of water from the cells, causing damage by dehydration. In this process, as the water leaves the cells, the concentration of solutes increases in order to reduce the risk of frostbite. However, as the ice keeps on growing, the cells continue to dry out, which can eventually lead to tissue necrosis, growth retardation, and even plant death.
The faster the cellular cooling, the greater the damage. The same happens if the increase in temperatures after the frost is quick, that is, the more abrupt the change in temperature, both intracellular and extracellular, the greater the damage and stress the plant will suffer.
One of the main problems we find because of these late frosts is a decrease in crop production. When the crop is in full bloom, a late frost could reduce, if not end, the viability of flowering, affecting the fruit setting. In order to mitigate the stress and damage due to low temperatures, there are two types of methods:
These methods have to do with:
Active methods:
These are methods that intervene directly in the crops. Examples of these methods are: physical isolation barriers, extra water supply, air and plant heating, air homogenization with fans or the application of biostimulant solutions.
Therefore it is with these active methods where Herogra Especiales products play an important role in mitigating the effects that frost and cold stress cause in crops. Specifically, within its broad portfolio, we will focus on the biostimulants category. Among other benefits and contents, biostimulants have a range of components that help fighting extreme weather situations, such as the one that concerns us, protecting the plant from within. Among these components we find:
As per frosts, it has been observed that the solution to the “frost” phenomenon is based on the accumulation of antifreeze proteins (AFP), since the AFPs interact with the ice crystals, adhering to the surface and preventing the bonding of water molecules. For this reason, among others, it is necessary to have a good concentration of amino acids in our plant, able to synthesize antifreeze proteins for our crops.
At this point, it is necessary to take into account that, in times of stress due to low temperatures, the rate of absorption of amino acids by the plant decreases, so it is essential to add them with products providing free amino acids.
However, amino acids not only have an effect on the above, but also improve the preservation of the firmness of the plant cell membrane, minimizing the damage by freezing. Finally, the biostimulant effect of the amino acids promotes the quick recovery of the post-frost crops and promotes the formation of cells and new tissues in the plant.
Having analyzed all the above and thanks to its extensive and proven experience, Herogra Especiales makes the following biostimulants available to the farmer, with the aim of protecting crops from late frosts:
This species of seaweed grows in the North Atlantic, where it is subjected to very extreme conditions of development and sudden changes in temperature. This habitat makes this seaweed develop a large number of highly functional secondary metabolites for crops. In addition, thanks to the cold extraction method used, all the natural properties and active ingredients of this species are preserved intact.
Aminomar Forte: this biostimulant, besides containing Ascophyllum nodosum seaweed extract, has an extra supply of amino acids, NPK nutrition and micronutrients to prevent deficiencies.
Thanks to its composition, besides mitigating cold stress in the crops, it provides biostimulation and nutrition, all in one product.
In addition, its content in GABA (Gamma Amino Butyric Acid) and betaines increases its osmoprotectant function, generating a number of metabolites and improving the efficiency of the plant, contributing to its resistance to environmental stress.
Its content in short-chain peptides means that it also has various effects on plant metabolism, activating hormonal synthesis, as well as crop growth and production.
Its biostimulant effect increases the responsive capacity and speed of recovery of the crops against unfavorable external conditions, besides playing an important role in the synthesis of proteins and enzymes, essential for the proper functioning of plant metabolism.
Its application allows for the recovery of the plant in general stress situations, such as frost, besides playing an important role in the synthesis of proteins and phytohormones (auxin, cytokinin, polyamines and prophyrins), which regulate the proper development of the plant.
Regardless of whether we apply these products preventively or at a later stage, we will be able to increase the resistance of the plant and its vitality through biostimulation, an effect that will be reflected in the improvement of the final yield.