Pears under cover are the best

Three years ago, a fruit producer on Zealand in Denmark was faced with a scab challenge. Should he destroy the young pear trees infected with scab or should he invest in covering them with a roof? He chose to invest in a roof, which turned out to be a great investment.

2018.02.07 | Kirsten Haug

The Madsen family established their fruit plantation on Zealand in 2008. It consists of mainly apples; however, the family wanted to offer their customers other fruits than apples and decided in 2011 to try pears. They planted two varieties: Herrepærer, which is a well know Nordic variety and Fritjof, which is rarer. The trees are planted alternately in a 70-meter long row.

- We decided to move here because it is close to a large lake and it is therefore, relatively windy here. Wind is important in order for trees and fruits to dry quickly, so that fungal spores cannot establish themselves. That is also the reason why we placed the plantation at the top of a hill, where the wind hits from all sides, and where no plantation had been before, explains Lars Madsen, who owns the plantation along with his wife Jette.

In recent years, Denmark has experienced heavy rainfall. However, Lars Madsen points out that it is a misconception that heavy rain is the main problem; it is rather silent rain without any wind that causes a problem, because the trees take longer to dry. 

No use of pesticides
Although, certain organic pesticides are allowed in Danish organic fruit production, Lars Madsen and his wife are not using any.

It's been a good investment to cover our pear trees, Jette and Lars Madsen confirm.- We only use fertilizers and water during dry periods. Along with our consultant we chose some apple and pear varieties that are robust and that are not as susceptible to diseases. Our apples are fine, but already into the second year, the pears were affected by scab. And the following year it was even worse, and we were on the brink of giving up. However, we decided to give the pear trees one last chance and take part in an experiment where trees are covered with a roof, Lars Madsen explains and continues:

- The first roof, we build, was destroyed during the first storm we had. However, the design we have now we can certainly recommend – it is efficient and easy to handle once it has been set up. 

Eating with one’s eyes
The cover reaches about 1 meter down on each side of the tree and still most of the tree is protected against the rain. Jette and Lars Madsen find the roof to be a good investment.

- We are consumers like everyone else and we eat with our eyes. Prior to covering the trees the fruits were totally damaged by scab and we could not sell them. Only our cows were happy to eat them. Now that the trees have cover, we can sell every single pear, even pears from the branches hanging low. Over a period of three years we have improved our selling percentage of pears from 0 to 95-100, Jette Madsen points out.

For the cover they have invested about 125 DKK (about 17€) per meter and therefore the selling price per pear has also increased slightly. 

- Our selling price is slightly higher for the pears than for our apples, but that is because we have had to invest in the roof. Our customers understand why and we are able to sell every single piece of fruit, explains Jette Madsen.

Less weed and longer shelf life
Jette and Lars Madsen explains that constructing the roof can be somewhat an effort, if the trees have already been planted. However, once the roof is in place it requires absolutely no work. An additional advantage of the roof is the reduced amount of weeds along the base of the trees – this is due to the dryness of the ground caused by the roof. And a further bonus is the fact that the fruits have a longer shelf life when grown under a roof.

Once the fruits are picked Jette and Lars Madsen will start rolling up the plastic that makes up the roof. Each roll is fastened at the top wire of the roof. They use a latter or stilts to reach to the top. They do not roll out the plastic until the following spring when the trees are offering yet another season filled with beautiful pears. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Jette and Lars Madsen took part in the project ProtecFruit and had pear trees that were covered by a roof and some that had no cover. In that, way the two growing environments could be compared. Pears that had cover (to the left); pears without cover (to the right).  

 

The roof that Jette and Lars Madsen are using has three layers of plastic. Each layer is displaced from the others. The plastic is kept in place by cross beams at the top of the row of trees and with snaphooks.

This design is strong when it is windy, because the layers of displaced plastic allow the wind to move in between the layers and out on the other side. Hence, the plastic does not rupture. The roof is expected to last about five years.

 


Read more about:

  • ProtecFruit

***

The original of this article was in Danish. It was published in the magazine Gartner Tidende no. 15, december 2017.

ProtecFruit is founded by GUDP by the Ministry of Environment and Food of Denmark, it is a part of the Organic RDD-2 programme, coordinated by ICROFS.

Agriculture and food
Tags: ProtecFruit; roof over trees, scab, fungal diseases, pear production, apple production