We have been hearing about climate change for many years and we are feeling nature manifesting itself with greater intensities in winter and summer. Climate change is a global concern, as temperature is a critical factor for successful agriculture and crop growth. Keeping crops at the right temperature is essential for their healthy development, but rising temperatures represent a growing threat to farmers and their crops. Each plant has its own optimal temperature range, above or below which its growth is compromised. The right temperatures allow plants to perform essential processes such as photosynthesis, nutrient uptake and transpiration. When temperatures are too high or too low, these processes can be negatively affected.
In general, in the case that concerns us in this article, warmer temperatures tend to accelerate crop growth, but if they are excessive, they can cause thermal, radiative and water stress, causing production to lose value in the market. Therefore, keeping crops within their optimal temperature range is essential to ensure healthy development and an abundant and profitable harvest.
Another problem related to rising temperatures is the increase in sunburn on crops. High temperatures and intense solar radiation can damage the surface of the leaves and fruits of plants; this damage can weaken them and make them more susceptible to diseases and pests.
I remember that at the end of June this year, we received a visit from some Mexican friends from GlobalMet. They warned us and predicted everything that was coming for the second half of this year in Chile and the truth is that they were not wrong; the El Niño phenomenon in terms of the rains in June and August, the lowest number of frost events, the lowest accumulation of cold hours, the high zero isotherm, the lowest number of degree days for the end of winter and spring, the late rains of this last quarter of the year and the excessive temperatures of our summer in the southern hemisphere. The guys from GlobalMet told me that when they traveled to Chile from the state of Sonora, Hermosillo in Mexico, they left with temperatures close to 50 °C, and that was the last week of June this year 2023.
In the vast majority of cases, what happens in the northern hemisphere is often repeated in the southern hemisphere; and by December 1st we begin meteorological summer and high temperatures, high radiation, low relative humidity are forecast, and these three conditions together are worsened by winds that cause dehydration in plants and fruit.
Excessive solar radiation affects fruits and vegetables, causing burns and lesions on leaves, stems, trunks and the fruit itself; this damage caused by sunstroke causes millions of dollars in losses, reducing the commercial quality of the fruit and, therefore, the yield of the crop.
Sun damage is a symptom of a general syndrome called thermal and radiative stress, with possible consequences of water stress. We have always been concerned with understanding how damage affects the fruit. However, it has been detected that the impact on yield, soluble solids levels, obtaining better sizes, etc., is on the tree or plant as a whole.
The excess photochemical energy that cannot be used in photosynthesis is diverted to other photo-oxidative reactions, which generate free radicals and damage cells by the synthesis of other substances, usually acids.
Solar radiation is composed of infrared light (about 501 TP3T), visible light (451 TP3T) and ultraviolet light (4-71 TP3T). Infrared and visible light are primarily responsible for heating the fruit, while ultraviolet light is responsible for tanning.
Some sun damage to fruit can be classified (example in apple trees)
- Burn damage with necrosis: It is caused by heat (thermal stress), when the surface temperature of the fruit in apples reaches 48 ± 1 ºC for 10 minutes. The cells die and later a brown or black colour (necrotic tissue) or a dark sunken spot appears.
- Common browning or burning: Typical symptom of sun damage resulting in a yellow, brown or tan patch on the sun-exposed part of the apple, the cells do not die and the damage is initially superficial, although if we make a deeper observation of the pulp in cold storage, we will see that there is damage. This damage occurs when the temperature of the fruit reaches between 42 to 47 °C for one hour, depending on the susceptibility of the variety.
- Photooxidation burns (or discoloration): When fruit is left in the shade and exposed to direct sunlight too quickly, it is prone to sunburn (highly loaded trees). The same happens when boxes of harvested fruit are left in intense direct sunlight for a relatively short period of time. Exposed fruit shows a whitish discolored area on the skin, which within a few days turns brown, black and necrotic.
EQUI-SUN is a transparent, completely residue-free sunscreen with a great crop-stimulating capacity. It acts by forming a transparent film that prevents sunburn caused by high temperatures and solar radiation. Its mechanism of action helps hydrate cells and generate chlorophyll for greater sun protection capacity. The product also contains natural sunscreens, which reduce the incidence of sunlight on the crop while helping the product to last longer; and polysaccharides, which help prevent fruit cracking.
The main advantages of EQUI-SUN are: low doses, greater proven protective effect of 30 days, lower cost per hectare, zero-waste and zero-deposit product, application with drone and all types of broth application machines, not attracting mites, lower environmental and ecological impact and product validated with official tests by advisors in Chile and Europe.
EQUI-SUN also helps to protect floral induction, which corresponds to physiological changes that occur in a bud and that determine its evolution into a flower bud; subsequently, the morphological differentiation that follows this change and leads to the appearance of floral beauties is known as floral differentiation. These phenological states are affected by high temperature conditions above 28 degrees Celsius for more than 5 hours, high radiation above 1600 micromoles, low relative humidity below 30% and winds that cause dehydration and also possible water stress. The action mechanism of EQUI-SUN is to form a good fixation on the surface of the plant, with antioxidants of carotenoid pigments, tannins and polyphenols, forming a film that absorbs and reflects solar radiation at a wavelength between 200 and 800 nanometers of light, protecting against a broad spectrum of infrared and ultraviolet radiation.
This film increases water retention inside the cell, keeping the internal cell temperature lower, avoiding premature paralysis of the plant and without staining the fruit, a major difference that makes it the best clean alternative to kaolin.
In addition, Equi-sun contains low molecular weight polysaccharides that promote the formation of pectins, which are the main component of the cell wall, providing: Cell elasticity (Ca2+, B+), turgor, ionic balance, mobilize salts and fluids (Ca2+, B+, Fe2+) reducing internal pressure and cracking.
EQUI-SUN also helps to provide starch reserves, since the product contains this element, in addition to cellulose and sugars. It is important to note that EQUI-SUN is a photosynthesis enhancer, transforming solar energy into sugars and giving the fruit an increase of 1 degree Brix, improving its organoleptic condition.
It is a water-resistant product: long persistence; unlike Kaolin, it does not stain the crop after its application; it does not require subsequent washing of the fruit; unlike other sun filters on the market, it does not attract mites; it increases cellular elasticity preventing the appearance of cracks and saving production costs; it increases photosynthesis allowing a greater production of sugars and better nutritional balance, transforming into better organoleptic quality of the fruit: it is a biostimulant and anti-stress, it reduces the temperature of the crop avoiding early vegetative stop and allowing a higher quality and flavour of the fruit; EQUI-SUN can be applied to all types of crops, it has good fixation, which allows it to have a long persistence; it is also a product that is respectful of the environment and useful fauna (Bombus, Orius, Swirskii, Nesidiocoris…)
In summary, EQUI-SUN helps reduce cracking and sunburn, protects floral induction in pre-harvest; and also helps protect bud differentiation and provides starch reserves in post-harvest.
Finally, EQUI-SUN received recognition in October 2022 at Fruit Attraction in Madrid, Spain, being a finalist in the Innovation Hub Awards 2022, for being an innovative product in the category of sustainability and commitment actions, a category that is key to the proper functioning and future of our planet.
The product's recognition is not only in Chile, it is already a recognized product in Europe, thanks to the work of Deygest SL and the research center of the Faculty of Biochemistry of the University of Barcelona who carry out all the research and development of this and other products more present in Chile and in the world.
