Excessive sun exposure or sunburn: what it is, how it develops, and how to fix it in fruit

• Avoid excessive and sudden exposure of the fruit to direct sunlight, especially during periods of peak radiation intensity.

• Maintain sufficient leaf cover around the fruit to provide natural shade during the hottest hours of the day.

• Avoid excessively heavy pruning during periods of high radiation and high temperatures.

• Plan pruning to avoid the sudden exposure of large quantities of fruit that were previously protected by the leaves.

• Avoid unnecessarily removing leaves that provide direct shade to the fruit.

• Maintain adequate soil moisture to promote transpiration and the natural cooling capacity of the plant tissues.

• Avoid prolonged periods of water stress during the fruit growth and ripening stages.

• Maintain a consistent irrigation schedule during periods of high temperatures and high solar radiation.

• Pay close attention to crops after episodes of strong winds, hail, foliar diseases, or any other cause that results in significant leaf loss. • Reduce water stress before periods of extremely high temperatures are expected.

• Use shade netting when weather conditions or crop characteristics indicate a high risk of sunburn.

• Select varieties less susceptible to sunburn when the crop is grown in areas with high radiation and extreme temperatures.

• Maintain balanced nutrition to promote proper leaf development and good fruit coverage.

• Avoid nutritional imbalances that can lead to excessive leaf loss or reduce the crop's ability to adapt to environmental stress.

• Control diseases and pests that can cause defoliation and prevent fruit from being directly exposed to the sun.

• Avoid interventions that drastically reduce leaf area during periods of highest risk.

• Monitor fruit located in the most exposed parts of the plant, especially those facing south or west in sensitive crops. • Conduct regular inspections during heat waves to detect the first signs of discoloration or necrosis.

• Avoid unnecessary handling of fruit during periods of extreme heat, as mechanical damage can increase the sensitivity of exposed tissues.

• Maintain adequate soil moisture during periods of rapid fruit growth.

• Improve soil water retention capacity when necessary to reduce significant moisture fluctuations.

• Use appropriate mulches to decrease soil water evaporation and help maintain more stable moisture levels.

• Prevent excessive weed competition for available water.

• In particularly sensitive crops, use authorized protective products that can form a film or increase the reflectance of the fruit surface, always following the corresponding authorization and conditions of use.

• Apply protective measures before episodes of extreme radiation when their mode of action requires preventative coverage. • Remove severely damaged fruit once it has completely lost its commercial value and could hinder harvesting.

• Prioritize preventative measures, since once cell damage has occurred due to excessive radiation, there is no phytosanitary treatment capable of regenerating necrotic tissue.

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