How to Prevent Apple Sunburn and Protect Your Orchard Profit?

Editor’s Note: This article is part of our Hail Netting Complete Guide. Visit the Hub for the full breakdown of hail protection systems, installation, and selection guides.

Apple sunburn can cost 10–50% of a crop in a hot year — and it cannot be repaired once it happens. The most effective prevention is netting: a 20–30% shade or hail net lowers fruit surface temperature by 4–6°C, keeping the skin below the 46°C point where browning begins. The goal is to hold the surface under the threshold, not to treat the damage after.

Apple sunburn is more than a cosmetic issue — it’s a major economic concern for growers worldwide. Excessive sunlight and heat cause fruit burn that lowers quality, cuts market value, and can take yield losses of up to 50%. The good news: with the right protection, sunburn is preventable.

What Causes Apple Sunburn?

Apple sunburn is surface heat stress — it happens when fruit faces high temperatures, intense solar radiation, and low wind at the same time, and worsens during heatwaves or under clear, low-humidity skies. Studies put apple yield losses from sunburn between 10% and 50%, depending on severity and regional climate.

The 3 main types of apple sunburn

• Photooxidative sunburn: occurs when previously shaded apples are suddenly exposed to sunlight, causing bleaching from light stress.
• Sunburn browning: happens when the apple surface reaches 46–49°C, producing yellow or bronze discoloration.
• Sunburn necrosis: the most severe form, occurring around 52°C, causing cell death and sunken brown-black patches.^[1]

These not only spoil appearance but also reduce shelf life and consumer appeal — which is why prevention matters more than any after-the-fact remedy.

Watch: why apples get sunburned and how to stop it

(Video by EyouAgro: understanding orchard microclimate management)

How Can You Prevent Apple Sunburn?

Installing protective netting is one of the most effective and proven ways to reduce apple sunburn — it works by lowering fruit temperature, filtering UV, and stabilising the orchard microclimate. Here is how a net helps:

Lower fruit temperature

A net creates partial shade that reduces direct radiation and prevents the surface overheating that triggers browning above 46°C. Choosing the right shade rate for your apples is the key lever here.

Block harmful UV radiation

Netting filters out excess UV that causes cellular damage and discoloration, while still passing the light the fruit needs to develop.

Improve microclimate stability

By reducing temperature swings and wind stress, a net creates a more stable growing environment — fewer of the sudden-exposure events that cause photooxidative bleaching.

Dual hail-and-sunburn protection

Many hail protection nets double as sunburn shields, giving orchards multi-layered protection from a single system. Pairing the right net colour with the right shade rate optimises both — see our guide to hail net colour.

What Shade Net Do Growers Use in Hot Climates?

In hot regions like Australia, Chile, and Spain, growers typically use black or white shade nets at 20–30% shading to hold ideal fruit temperatures. In the orchards we supply, a shade or hail net of that range reduces fruit surface temperature by 4–6°C — enough to keep the skin below the browning threshold without dulling coloration.

Frequently Asked Questions

What temperature causes apple sunburn?

Heat stress begins once the fruit surface temperature exceeds about 46°C, with browning between 46–49°C. Above roughly 52°C, sunburn necrosis can occur and the damage becomes permanent.

How much can a net lower fruit temperature?

A 20–30% shade or hail net reduces fruit surface temperature by about 4–6°C in our experience — often the difference between healthy skin and browning, since damage starts at 46°C.

Do shade nets affect apple colour?

A properly chosen net maintains good light diffusion while protecting from UV and heat, so it can protect against sunburn without dulling colour. Net colour and shade rate are the variables to get right — see our colour and shade-rate guides.

Which colour shade net is best for apples?

White or pearl nets are common for orchards because they reflect heat while passing enough light, while transparent net keeps colour best on red varieties. The right choice depends on whether sunburn or colour is your bigger concern.

Can hail nets also prevent sunburn?

Yes — dual-function hail-and-sunburn nets are common in modern orchards. The same net that stops hail also lowers fruit temperature and filters UV, giving you two protections from one system.

Can sunburnt apples be saved?

No — once the skin browns or develops necrosis, the damage is permanent and the fruit downgrades. Sunburn management is entirely about prevention: keeping the fruit surface below the heat threshold through the season.

References

1. Schrader, L., et al. (2001). Sunburn of apple fruit — sunburn browning and necrosis temperature thresholds. Plant Health Progress. DOI: 10.1094/PHP-2001-1004-01-RS

Conclusion

Apple sunburn is serious but preventable — and prevention is the only option, because the damage can’t be reversed. A UV-stabilised shade or hail net that drops fruit temperature 4–6°C protects quality, yield, and marketability through the hottest part of the season. For high-hail regions, a dual hail-and-sunburn net does both jobs at once.

Ready to protect your apples and profits? Tell us your region, variety, and whether sunburn or hail is your bigger risk, and we’ll recommend a net colour, shade rate, and system with a quote and sample. Get a customised netting solution.

Talk to Our Experts

Need guidance on crop protection solutions?

Connect with our specialists to discuss your needs and confidently start your project!

Reach out today

By Kevin Lyu | EyouAgro — 28 years (since 1996) manufacturing hail netting for orchards worldwide, from a factory with 8 production lines.

Next Reading

Why You Should Protect Solar Panels With Hail Netting

PV operators ask me whether hail netting is worth it for solar panels.

After 28 years supplying hail netting, the math settles it: a transparent net runs about $400–800 per acre a year and costs ~7% light, while one hailstorm can total a $400,000-per-acre array. Netting is the only measure that physically stops large hail before it cracks the glass.

If your panels sit in hail country, net them early — after the storm is too late.

— Kevin Lyu, EyouAgro

Why Is My Hail Netting Not Working? 8 Problems Diagnosed

In 28 years supplying hail netting I've learned the hard way: the problem a grower names is almost never the real cause. "Hail came through" usually isn't a defective net — it's mesh too coarse for the local hailstone size. A torn net is usually over-tensioned, not weak. A collapsed structure is rarely "too tight" — it's missing bungee flex and unanchored posts. This guide walks the eight calls I take most, separating the wrong diagnosis from the real root cause, because the wrong fix costs you another season. — Kevin Lyu, EyouAgro

Why Choose Quad Crossover Hail Netting for Crop Protection?

Quad Crossover Hail Netting offers superior protection due to its four-yarn crossover design, making it highly durable against hail, wind, and birds. It is UV-stable and provides a micro-climate effect, promoting healthy plant growth.