5 biggest problems: Cherry cover systems

In fruit growing, it is important to have a rain protection system. Over the years, various foil hoods have been developed and built. Fruit growers are now familiar with many different types of foil covers. These include roll cover systems, foil systems and anti-rain canopies. Each system with its own advantages and disadvantages.

Foil covers have a positive impact on fruit growing. For instance, you can protect your cherries from the Suzuki fruit fly. Or prevent damage to your cherries from too much rainfall. But film hoods also bring problems.

In this blog, I want to discuss further the 5 biggest problems that occur with foil covers. These 5 problems we have heard from customers or are our own findings from practice. Based on these problems, I will also mention several practical examples and tips on how to deal with them.

The 5 problems

• Accessibility of the crop
• Climate under the plastic cover
• Humidity & infection pressure under the foil cover
• Recurring operations
• Quality of foil covers

Problem 1: Crop accessibility

I would like to start elaborating on the 5 problems of foil canopies with crop accessibility.

We can't deny it, but installing a foil canopy will compromise crop accessibility. You have to deal with the height of the system (usually 4.5 metres) to maximise working space.

Especially in the first and last row, there is less space. Due to the anchors, a steel cable runs through the row. What results is that only small fruit-growing tractors can drive in this lane.

Bonus: 
When buying/arranging your plot, think about how you want to place the system. This way, you avoid certain posts or anchors getting in the way when the system is built.

Problem 2: climate under the foil cover

Film covers are often fitted with woven or blown film. These foils have their own light transmission and lifespan. Each protection system will take a certain amount of ventilation and light. This will affect the fruit. Most of the time it's positive.

It also appears that bees have difficulty navigating properly under woven film. When the woven film is closed, a certain UV radiation is blocked, that is the UV radiation where the bee navigates on.

Example situation of Powerflex

With the Powerflex foil system, tests were done on heating and light loss under the system. The Powerflex system was compared to an orchard without the system. The system was built in 2016.

In 2020, the light loss under the canopy was 39%, in 2018 32% and in 2017 36%....
In terms of temperatures, the following finding was made:

In 2020, for example, it was noticeable that around noon was 2.5 to 3°C warmer under the canopy.
The above 2 points are just a small sample of the study. I will not elaborate further on the research in this blog.
If you are curious about the study of temperatures and light loss in film systems, read the following blog: Temperature measurements rain covers

Problem 3: humidity & pest pressure under foil canopies

Problems 3 and 4 are very close to each other. Higher humidity will also increase infection pressure. What we see is that under a foil canopy, humidity is higher.

This does not mean that the crop gets wet from rain, but that it remains damp with dew, for example. This is caused by removing some of the ventilation. Of course, not all ventilation is taken away. This also depends on the choice of canopy.

For example, if you choose insect nets on the side, this affects the ventilation in the system. This will keep the humidity higher, and will also be able to amplify problem 4.

This humidity can cause the pressure on infection to increase. But there are also several ways to keep the infection pressure low.

Bonus: Mount insect netting on the sides of your system to keep the Suzuki fruit fly out of your orchard.

Problem 4: the recurring work

With every foil hood, apart from the supplier, there are recurring operations. Like rolling up and unrolling the system. Or maintaining the canopy.  

In addition, when using a film cover, you also need an aerial platform. So you can choose to buy one yourself, or rent one.

Rolling up and unrolling the systemt can differ for each rain protection system. For a Powerflex System, the film will be able to be rolled up in 40-50 hours per hectare. If you roll out the system then you will need around 20-30 hours.

Bonus:
Rolling up and unroll only in calm weather. With wind, it take much longer!
Download our checklist for film canopy maintenance: Maintenance of fruit canopies

Problem 5: quality of foil covers

Rain protection systems have been available on the market for a long time. Film systems have been around in the Netherlands for almost 15 years. Throughout the 15 years, there where suppliers that have proven themselves, but also systems that weren't that good.

In the Netherlands, we have to deal with a lot of wind and rain. That is where a film cover can make the difference. The construction must be solid enough to withstand wind and the film must be mounted in such a way that it keeps cherries or other fruit dry under the film cover.

Read more about collapsing systems here. Where do things go wrong and what should you look out for?

How come hail net systems and rain caps collapse?

Bonus:

When choosing a foil cover, pay close attention to the quality. And if the system has already proven itself. What do other fruit growers think of the system? And does it fit within your own requirements?