While sunlight is essential for plant health and development, on the other hand, when excessively intense, it can create tissue damage, particularly in fruits, with burns and/or browning of the epidermis. Depending on temperatures we can distinguish two types of damage: necrosis and browning. The former occurs when the temperature of the fruit (which does not correspond to that of the air) exceeds 52°C. The heat causes thermal death of epidermal and sub-epidermal cells inducing the formation of a necrotic spot on the side of the fruit exposed to the sun. Browning, on the other hand, occurs with fruit temperatures around 46-49 °C and does not result in necrosis but more simply causes yellow to bronze or brown spots to form on the sun-exposed side of the fruit. How to defend yourself
Techniques to defend against possible damage from irradiation and excessive temperature elevation (sunburn) are many and the effectiveness is linked, within the limits allowed by the temperature itself, to certain expedients and precautions.
If the temperature elevation in the tissues is caused by strong sunlight, it is advisable to use SunStop LG. The product possesses a filtering/reflecting action on electromagnetic radiation. It appears translucent when dry, but is capable of hindering the passage of radiation in the infrared fraction responsible for raising temperatures in plant tissues without at all interfering with normal photosynthetic activity. The treatment should be carried out beforehand on the vegetation and should be repeated at intervals determined by the growth rate of the plant (fruit) treated. The faster the growth rate, the closer the treatments will have to be in order to ensure constant and regular tissue coverage. Typically one treatment every 15 to 20 days during the period of highest intensity. Apply the product by foliar application before the air temperature exceeds 28-30°C. Repeat in case of runoff. Distribute on the side most exposed to insolation at rates ranging from 6 to 12 kg/ha depending on the crop and its stage of development. To supplement heat protection and for a more prompt recovery of the plant from stress, we recommend the use of Seaweed Mix (250 ml/hl) [or also of Seaweed Special at the same dosage] a couple of days before the peak is reached and thereafter weekly for 2-4 times.
To ensure the greatest effectiveness of treatments, apply preferably in the evening or at least during the cooler hours of the day.
Avoid heat/solar radiation damage.
