Sunburn damage (sunstroke) is common in fruits because of the high levels of solar radiation they endure during hot times of the year. Fruit yield losses due to sunburn can reach from 6% to 30% depending on the season and type of fruit. In order to avoid this, the farmer should follow best treatment practices to minimize sunburn, such as maintaining good leaf coverage of the fruit, using shading meshes and fruit bagging, and applying specific products to protect the crop from solar radiation.
SUNBURN IN CROPS
Sunlight is the main source of energy used in plant photosynthesis to convert carbon dioxide and water into carbohydrates used by the plant to grow stems, leaves, roots, and fruits. Life would not be possible without this energy source. Besides, to a certain level sunlight is very useful to improve quality and yield, and also reduces the incidence of pests and diseases. However, if sun intensity is higher than optimal, plants suffer physiological problems, sunburn being one of them. This damage is common in fruits grown in areas with very hot summers, where there is high solar radiation in the ripening stages.
Sunstrokes also occur when the weather is cool or mild followed abruptly by hot, sunny weather. Severe sunburn alters the cuticle and damages both the epidermis and epidermal sub-tissues.
When the air temperature rises above 30°C to 35°C during the day, photosynthesis is likely to decrease, and in turn crop yield potential.
What can we do to reduce or avoid sunstrokes?
Some practices to reduce sunstrokes are the following:
• Use of fruit varieties that are more tolerant to high temperatures.
• Treating the tree so it develops an optimal plant cover to protect the fruits, mainly in varieties that are very likely to suffer from sunstroke.
• Avoiding excessive pruning in summer and leaf removal.
• Using shading meshes.
• Fruit bagging. The technique of individual fruit bagging is used to avoid sun damage, including damages from insects or diseases.
• Using protection products on the leaf and fruit surface to reduce some of the solar radiation and temperature.
Herogra solutions for sunstrokes
Herogra Especiales offers the product EKLIPSO, which is used to reduce sunstrokes or sun damage in the crop.
It is a micronized calcium-based nutritional product stabilized with sunscreen effect. It has been developed using a multi-technology which combines two Herogra Special patents for a total effectiveness. Eklipso contains coadjuvants and special compounds that make it the best option in the market to increase crop resistance to stress caused by high solar radiation.
It creates a protective physical barrier against radiation, thus avoiding an increase of plant temperature, as well as preventing and correcting calcium deficiencies thanks to its high calcium concentration.
Trials show that the application of Eklipso on crop helps reducing the temperature in leafs and fruits and the number of fruits damaged by sunstroke (Figure 1), as well as reducing stress in the crop by 42% compared to not applying it. This is assessed through the MDA parameter (Figure 2), which is a measurable stress parameter.