31. May 2022

University of Bonn helps to propagate rare apple type University of Bonn helps to propagate rare apple type

Biologische Station im Rhein-Sieg-Kreis wants to plant endangered "Adams Parmäne" on its land

"An apple a day keeps the doctor away" is an old English saying that means apples are healthy, so you should eat one every day. A very special specimen is the type "Adams Parmäne", which is currently on the red list of endangered native crops in Germany. The Wiesengut Teaching and Research Station at the University of Bonn is working with pomologist Barbara Bouillon from the "Biologische Station im Rhein-Sieg-Kreis" to preserve this special apple variety. She shows how this can work and why it is so important right now.

The Adams Parmäne - on Campus Wiesengut © Photo: Volker Lannert/ Uni Bonn

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The apple type „Adams Parmäne“ was bred in the county of Norfolk in England by a Mr. Adams in the early 19th century and was later spread to Germany. It belongs to the winter apples because its fruits ripen in early October, are ready for consumption from December and can be kept until March. The slightly conical, green-yellow-red variety is a good dessert apple with its aromatic sweet-sour taste. It is highly endangered and is therefore on the Red List of endangered native crops in Germany. This list includes all species groups of native useful plants and their varieties and cultivars that were adapted to local conditions and were of importance in Germany. Nowadays, the Adams Parmäne is almost not found in any nursery assortment throughout Germany and is therefore almost never replanted.

The Adams Parmäne is just one of numerous examples of the loss of genetic diversity on earth. This is not only about the extinction of wild animal and plant species or the loss of entire habitats, but also about the genetic impoverishment of crops available to humans. So far, there is only one registered tree of the Adams Parmäne variety in the entire Rhein-Sieg-Kreis. This one is located at the "Campus Wiesengut", a teaching and research station for organic farming at the University of Bonn. "In view of increasingly extreme climate changes, we cannot yet say with certainty what genetic resources mankind will be dependent on in 20, 50 or 100 years. Preserving livestock and crop diversity in their natural habitat therefore plays a very essential role," says Campus Wiesengut scientific coordinator Dr. Martin Berg.

Cooperation over many years

The Wiesengut Campus and the Department of Agroecology & Organic Farming have been working intensively for many years with the Biologische Station im Rhein-Sieg-Kreis, an institution at the interface of official and voluntary nature conservation in Rhein-Sieg-Kreis. "Like many old apple varieties, the Adams Parmäne is very undemanding and robust, so it can still be grown in adverse locations and grows very old," says biologist Barbara Bouillon, deputy managing director of the "Biologische Station" in Eitorf. In addition, the fruit can also be stored until late winter." However, the apple type has an image problem: "Unfortunately, it doesn't stand out and potential eaters tend to reach for more red-colored apples, which are not necessarily better in terms of taste, however, usually much worse."

The botanist and pomologist has been working at the Biostation for years to preserve old, endangered fruit varieties. The goal of the collaboration is to strengthen the populations of such highly endangered plant species as the Adams Parmäne. Propagation in apples, for example, works through a process known as "grafting." The simplest method is copulation. For this, one cuts off a healthy, one-year-old shoot from the apple tree and cuts a so-called scion about the thickness of a pencil from the middle section. This should be at least finger-long and have four buds. As a so-called grafting rootstock serves an apple seedling of the same thickness as far as possible. The shoot is then grafted onto the healthy seedling. After the graft has successfully grown, it forms the root of the new fruit tree, while the scion gives rise to the trunk and crown. If the scion sprouts in the spring, the grafting was successful.

The young Adams Parmäne trees are to be planted in the orchard meadows of the Biological Station in gaps left by dead trees. The older a tree gets, the more interesting it becomes from a biodiversity perspective, as numerous insects, birds and many other species benefit from the tree.

In the future, there will be even closer cooperation between the "Biologische Station im Rhein-Sieg-Kreis", the Wiesengut and the Department of Agroecology and Organic Agriculture at the University of Bonn. Various extremely rare species from the Rhein-Sieg-Kreis, of which only single specimens of the respective populations still exist at the natural site, will be sown and cultivated by the "Biologische Station" at the Wiesengut in order to plant them out again at a later date at the original site.

The "Campus Wiesengut“

The Campus Wiesengut was made available to the Faculty of Agriculture of the University of Bonn in 1985. The farm is a member of the "Naturland" and "Bioland" farming associations. It is integrated into the teaching and research focus "Environmentally compatible and site-appropriate agriculture" of the Faculty of Agriculture at the University of Bonn.

Contact:

Dr. Martin Berg
Scientific Coordinator
Campus Wiesengut
University of Bonn
Phone: 02242 - 913 4282
E-mail: berg@uni-bonn.de

Barbara Bouillon
Biologische Station im Rhein-Sieg-Kreis e. V.
Phone: 02243 847906
E-mail: info@biostation-rhein-sieg.de

Barbara Bouillon - from the Biologische Station im Rhein-Sieg-Kreis cuts a scion to size. © Photo: Volker Lannert/University of Bonn

Here, a copulation cut was made - at the lower end of the cut scion. In the rootstock, this is done at the upper end. The cut surfaces should be four to five centimeters long for good coverage. © Photo: Volker Lannert/University of Bonn

A finishing tape is used - to join the assembled area by tightly wrapping the thin, stretchable plastic film around the joint from bottom to top. © Photo: Volker Lannert/University of Bonn

Ready is a grafted apple tree: - The young Adams Parmäne is to be planted in the gap of a fruit stand. © Photo: Barbara Bouillon

So far, - there is only one registered tree of the Adams Parmäne variety in the entire Rhein-Sieg-Kreis. This one is located at the Wiesengut. © Photo: Volker Lannert/University of Bonn

Barbara Bouillon - plants the grafted little tree in a pot. Later, the Adams Parmäne will be planted a gap of a meadow orchard. © Photo: Volker Lannert/University of Bonn

Interviews with Barbara Bouillon and Dr. Martin Berg:

Dr. Martin Berg, scientific coordinator of the Wiesengut Campus of the University of Bonn:

What exactly does the cooperation with the pomologist Barbara Bouillon look like?
The cooperation includes, for example, the joint supervision of final theses within the framework of the course of studies in Nature Conservation and Landscape Ecology. Furthermore, a few years ago a comprehensive package was agreed with the Biostation within the framework of contract nature conservation for the biodiversity-friendly use of grassland areas near the river Sieg. In the future, we will devote ourselves to the protection of the highly endangered meadow ants on the areas of the Campus Wiesengut in another large project. Finally, together with Ms. Bouillon, we will establish the Ex-situ Conservation Station (ESE Rhein-Sieg) for highly threatened plant species of the Rhein-Sieg-Kreis. Ex-situ measures for the conservation of biodiversity are those that take place outside the actual habitat of a species, for example in botanical gardens, in zoos or the like. The long-term goal is to strengthen populations of these species. This activity is intensively integrated into research and teaching.

How is the protection of biodiversity linked to the work at the meadow farm?
Since taking over the experimental farm in 1989, the Wiesengut has been continuously dedicated to the protection of biodiversity until today. Thus, right at the beginning, more than 1500 meters of hedges and landscape structures were planted and established. In the very monotonous landscape at that time, retreat areas for animals were to be created, which play an essential role for the stability of the agricultural ecosystem and thus also for yield security. All measures were permanently expanded, optimized and evaluated within the framework of accompanying scientific studies. Expert colleagues therefore also refer to the campus appreciatively as the Biodiversity Campus.

What are the main research and work areas at Wiesengut?
Research activities at the Wiesengut campus are dedicated to the question of how the goals of agricultural production, nature conservation, and resource protection can be better united through the targeted design of agroecosystems, and how the health, stability, and resilience in such systems can be promoted in the long term. One focus is on designing crop systems through diversification, that is, greater use of diversity. This includes broadening the range of crop species, for example, through increased cultivation of medicinal and aromatic plants, or the targeted promotion of pollinating insects through flower-rich plant species mixtures. Crop and grassland systems are studied at different spatial and temporal scales, from individual plants to landscapes, from roots in the subsoil to digitized remote sensing of entire agroecosystems.

Barbara Bouillon, Biologische Station im Rhein-Sieg-Kreis:

Ms. Bouillon, you are a pomologist. What exactly do you mean by that?
A pomologist is familiar with different types of fruit and can provide information on their growing characteristics, susceptibility to disease and the utilization of the fruit. Ideally, she can also identify the fruit varieties by looking at the fruit.

What is actually special about the apple variety "Adams Parmäne?"
The Adams Parmäne is an apple type that is very undemanding and can be grown even in adverse locations - e.g. dry locations or high altitudes. It is the inner values that matter, as it is an aromatic dessert apple.

What is the importance of old apple varieties for nature conservation?
Basically, all fruit trees on an area increase the biodiversity of the area through the flower and fruit supply. Many - but by no means all - old varieties, like the Adams Parmäne, are very robust and grow very old on suitable sites. The better a tree is adapted to the site characteristics, the longer it remains healthy and the older it becomes. Only at a higher age do the trees become particularly interesting from a biodiversity point of view. Numerous insects, birds or dormice - such as the dormouse - use the extensive crown space or bark structures as habitat. Even in a no longer vital state, a fruit tree still offers a diverse habitat with dead branch sections or branch outbreaks and trunk cavities. This is where bats, deadwood beetles or wood decomposing fungi get their money's worth. Even if the latter "herald" the end of the tree until it does, many species still benefit from the tree.