Introduction
Rain covers are widely used in sweet cherry cultivation to reduce cracking and enhance yield.
However, they also significantly influence the orchard’s microclimate, which can affect fruit quality, including firmness and other key attributes.
Understanding these impacts is crucial for growers aiming to optimize their cultivation practices.
What Are the Microclimate Effects of Rain Covers?
Rain covers affect the orchard’s microclimate by reducing solar radiation, increasing air temperature, and altering relative humidity.
This helps protect cherries from excessive heat and UV rays, reducing cracking, but can also affect cherry photosynthesis, resulting in lighter fruit color.
Additionally, the covers increase humidity, which can raise the risk of fungal diseases.
Managing these changes is essential for optimal cherry growth.
Reduction in Solar Radiation
Rain covers block a significant portion of sunlight.
Research shows reductions at midday of:
- 50% total solar radiation
- 58% photosynthetically active radiation (PAR)
- 66% UV-B radiation
Why This Matters
Solar radiation influences:
- Fruit color development (anthocyanins need UV light)
- Sugar accumulation
- Photosynthesis efficiency
- Fruit firmness
While reduced radiation protects against heat and sunburn, it can also cause lighter color and slower biochemical development in the fruit.
Changes in Air Temperature
Rain slightly increases canopy air temperature due to heat being trapped below the covering material.
Effects include:
- Faster fruit growth and softening
- Increased metabolic activity
- More rapid sugar usage (but not necessarily higher SSC)
This warming effect is generally beneficial early in the season but can reduce firmness at harvest if unmanaged.
Altered Relative Humidity
Rain covers modify humidity conditions around the canopy.
Humidity decreases directly beneath the plastic surface but may increase slightly within the canopy.
Why humidity changes matter:
- Lower humidity reduces certain fungal diseases
- Higher humidity inside the canopy can affect leaf transpiration
- Micro-moisture shifts can influence fruit firmness and turgor
These factors collectively shape fruit development.
Why Is This Important?
These microclimate changes directly influence cherry fruit quality.
Positive effects:
✔ Less fruit cracking
✔ Reduced rain damage
✔ Protection against UV stress
Potential drawbacks:
✘ Lighter fruit color (especially bi-color varieties)
✘ Slightly reduced firmness
✘ Altered sugar accumulation
✘ Adjusted harvest timing
Growers must understand these effects to optimize shade, ventilation, and material selection.
Solution: Using Advanced Rain Cover Materials
To overcome the limitations of traditional PE tarpaulin, EyouAgro developed the Anti-dripping Cherry Cover Film.
Advantages:
- 90% sunlight transmittance → maintains natural light spectrum
- Improved UV management → supports anthocyanin formation
- Anti-drip performance → reduces fruit infection risks
- Stable microclimate → minimizes firmness and sweetness reduction
This material ensures protection without sacrificing fruit quality.
Conclusion
Rain covers play a critical role in reducing cherry cracking and improving yields, but they also significantly impact the orchard microclimate.
By understanding these changes, growers can make informed decisions about rain cover materials and management practices.
Using advanced solutions like Anti-dripping Cherry Cover Film ensures optimal results for sweet cherry cultivation.
Enhance Your Cherry Orchard with Advanced Rain Cover Solutions!
Rain covers are essential for protecting cherries from cracking and improving yields, but understanding their microclimate effects is key to optimizing fruit quality.
At EyouAgro, we offer Anti-dripping Cherry Cover Films with 90% sunlight transmittance and advanced anti-drip features, ensuring optimal protection and growth conditions for your cherries.
Ready to improve your cherry cultivation?
Contact us today for expert advice and discover how our innovative rain covers can transform your orchard’s productivity.
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
FAQ – Microclimate & Rain Covers for Cherries
1. Does reduced solar radiation under rain covers affect cherry color?
Yes. Reduced UV-B limits anthocyanin formation, especially in bi-color varieties.
2. Do rain covers increase canopy temperature?
Yes. PE covers trap heat, raising canopy temperature slightly.
3. How does humidity change under rain covers?
Humidity may decrease just below the cover but can increase within the canopy.
4. Are advanced films better than traditional PE tarpaulin?
Yes. High-transmittance anti-drip films reduce quality loss while preventing cracking.
5. Do rain covers impact fruit firmness?
Yes. They can accelerate softening due to increased temperature and modified humidity.
