Rain covers are commonly used to protect sweet cherries from environmental stressors like rain and sunburn. However, they can have a negative impact on the fruit’s total phenolic content and antioxidant capacity. Understanding these effects is essential for growers who seek to optimize fruit quality while using rain covers.
Why Do Rain Covers Impact Sweet Cherry Phenolic Content and Antioxidant Capacity?
Rain covers can reduce the phenolic content and antioxidant capacity of sweet cherries by filtering sunlight, especially UV radiation, and reducing environmental stress. Phenolic compounds and antioxidants in plants are often produced in response to stress factors like UV exposure and temperature changes.
Rain covers limit UV radiation and stabilizes the growing environment, which reduces the natural stress response of the cherry trees.
As a result, cherries under rain covers produce fewer phenolic compounds and antioxidants, leading to a decrease in both phenolic content and antioxidant capacity.
Light Filtering
Rain covers filter out some of the solar radiation that reaches the cherry trees, including UV radiation. Research has shown that higher solar radiation and environmental stress promote the synthesis of phenolic compounds and antioxidants in plants.
Therefore, by blocking UV radiation, rain covers can reduce the synthesis of these beneficial compounds in cherries.
Reduced Environmental Stress
Some studies suggest that plants accumulate more phenolic compounds and antioxidants under stressful conditions as a defense mechanism.
Rain covers provide a relatively stable growth environment by reducing exposure to extreme weather conditions, which may lower the accumulation of phenolic compounds and antioxidants in the fruit.
How Does This Manifest in Different Cherry Varieties?
The effects of rain covers on phenolic content and antioxidant capacity are particularly noticeable in certain cherry varieties.
Total Phenolic Content
In all three varieties (‘Rainier’, ‘Bing’, and ‘Sweetheart’), total phenolic content is significantly lower in cherries grown under rain covers.
This suggests that the rain cover environment is not conducive to phenolic accumulation in cherries.
Antioxidant Capacity
The antioxidant capacity of cherries is also reduced under rain covers, though this effect is statistically significant only in the ‘Rainier’ variety.
This indicates that different cherry varieties may respond differently to the microclimate created by rain covers.
Why ‘Rainier’ is More Affected
‘Rainier’ is a two-tone cherry variety with yellow flesh and red skin, where the skin color is primarily determined by anthocyanins.
Anthocyanins are phenolic compounds with antioxidant properties.
By filtering UV radiation, rain covers can inhibit the synthesis of anthocyanins, which may explain why the decline in total phenolic content and antioxidant capacity is more pronounced in ‘Rainier’ cherries.
Solution: Reducing the Negative Impact on Cherries
To address the light-filtering issue caused by traditional rain covers, we recommend using Anti-dripping Cherry Cover Film, which allows up to 90% sunlight transmittance.
This solution helps maintain sunlight exposure while still protecting cherries from cracking, effectively reducing the negative impacts of PE tarpaulin on cherry growth and quality.
Conclusion
Rain covers can negatively affect the total phenolic content and antioxidant capacity of sweet cherries, especially in varieties like ‘Rainier’.
By filtering UV radiation and reducing environmental stress, these covers inhibit the synthesis of beneficial compounds in cherries.
Using innovative materials like the Anti-dripping Cherry Cover Film can help maintain optimal conditions for cherry growth while minimizing these negative effects.
Protect Your Cherries Without Compromising Quality!
Rain covers are essential for protecting cherries from environmental stress, but they can reduce phenolic content and antioxidant capacity. At EyouAgro, we offer Anti-dripping Cherry Cover Films that provide 90% sunlight transmittance, helping maintain optimal sunlight exposure and reducing the negative effects on fruit quality.
Want to enhance your cherry crop’s quality? Contact us today to learn more about how our innovative rain cover solutions can help improve both protection and fruit health.
Reference
Simón Pino,Miguel Palma,Álvaro Sepúlveda,ect, Effect of Rain Cover on Tree Physiology and Fruit Condition and Quality of ‘Rainier’, ‘Bing’ and ‘Sweetheart’ Sweet Cherry Trees
