Plant stress: how cold conditions affect plants and how to act to prevent damage
Effects of ice and low temperatures on artichoke, leek, wheat and lettuce crops
The recent storm Filomena that swept the Iberian Peninsula has brought with it an intense episode of cold weather and freezing conditions, with some of the lowest minus zero temperatures recorded in decades. It has been extremely cold, and this has meant that crops have also suffered, in the form of thermal stress which occurs when plants experience abnormal temperature conditions.
Although it depends on the magnitude, thermal stress either from heat or frost, can cause significant crop losses. In practice, there are strategies based on the use of biostimulants such as those that Seipasa designs, formulates, and markets, that help prevent and reduce the negative effects of plant stress.
Crops, whether vegetables, fruit trees, woody crops, or cereals, grow and develop within an optimal range of maximum and minimum temperatures. Each plant species has a certain capacity to tolerate stress caused by low temperatures, which varies depending on the plant variety or its nutritional state.
In the case of vegetables, for example, growing in hothouse conditions which enables better control of temperatures, is not the same as outdoor management. However, a cold snap or episode of extreme cold and sudden drop in temperatures can be lethal when the freezing temperatures we have experienced over the past few days are reached.
When this occurs tiny ice crystals form on the outside and inside of plant cells restricting the plant's metabolic processes. The cell membrane hardens due to the effect of the cold and this thermal stress affects basic processes such as photosynthesis, respiration or the absorption and internal translocation of essential nutrients and water.
In practice, crops that experience this type of low-temperature stress suffer impaired growth which affects and delays essential processes in their development such as flowering, development and fruiting. The result is a loss in crop yields and quality. In the most extreme cases, the plant freezes, wilts and dies.
How can we deal with plant stress caused by cold episodes?
Preventive methods to combat thermal stress in plants involve a series of crop practices which include selecting suitable varieties, nutrition management, maintaining soil clear of weeds or so-called smart irrigation systems to keep the environment inside hothouses as humid as possible.
Applying biostimulants is also key to increasing crop resistance and helping them to overcome plant stress caused by cold temperatures. The input of amino acids, for example, is essential for energy stimulation and the activation of metabolic processes in plants at moments of highest demand.
When plants face situations of stress, they concentrate all of their energy on vital functions, relegating others to a second plane. This is when energy consumption is critical, amino acids provide the necessary boost to regulate the plant and maintain its growth process and the development of the plant's organs. Kynetic4 is Seipasa's biostimulant, formulated with a combination of amino acids precursors with high-value amino acids, whose application encourages the synthesis of specific proteins at times when energy expenditure is critical.
Thermal stress caused by frosts can also cause damage to plant walls and tissues. Bryosei is a biostimulant solution that acts by healing and regenerating these tissues. Application of this biostimulant encourages sap to flow more quickly through the plant's vascular bundles, and for it to be transported to all parts of the plant.
Roots are also critical in situations of plant stress as they are responsible for absorbing and supplying the water and nutrients the plant needs to develop and grow. Radisei is a biostimulant for root use with a composition that includes Seipasa's exclusive strain of Bacillus subtilis that helps modulate stress caused by very extreme temperature conditions. Applying it allows a biological and physical barrier to be formed by a biofilm that covers the roots, establishing a symbiotic relationship. Radisei also encourages growth of new secondary roots and absorbent hairs.
In situations of stress caused by cold weather episodes and low temperatures, plants need all the help we can give them. Use of biostimulants of proven efficacy is a farmer's best ally, although on some occasions, as recently experienced with storm Filomena, Nature aligns with the harshest winter conditions and unleashes unusual, uncontrollable episodes of freezing temperatures and snow.