In recent decades, we have witnessed an extreme decline in the production of edible chestnuts due to the devastation of chestnut orchards by the diseases Phytophthora cinnamomi and Cryphonectria parasitica. European chestnut orchards are located at altitudes of 200 to 1,000 metres above sea level, where other agricultural production would hardly be able to replace them. Chestnut production plays an important role here. Farming the land planted with chestnuts is difficult. If chestnut orchards disappear, the consequence will be the end of any possibility of agricultural development, with all the economic, social and environmental consequences. Therefore, ambitious programs to plant new chestnut plantations have been launched in Europe in recent years.

Family farms

In the vast majority of cases, chestnut production is based on traditional family farms. The rural exodus of people in these difficult areas continues to lead to the abandonment of chestnut orchards. If the restoration programme were successful, it would certainly help to halt the devastation of rural communities across Europe. Restoring Europe’s chestnut orchards requires a comprehensive approach, not only involving the planting of new trees, but also the introduction of cultivation practices to ensure their longevity. This can only be achieved through further investment in research aimed at breeding disease-resistant chestnut varieties and improving soil health through organic farming methods.

High-quality planting material is essential to revitalise existing orchards and support the establishment of new orchards.

One effective way to restore chestnut orchards is to establish a comprehensive planting programme aimed at replacing lost trees in existing plantations with resistant chestnut hybrids. In an effort to obtain suitable resistant chestnut cultivars, the French National Institute of Agricultural Research (INRA) initiated an interspecific hybridization program in 1956 using the Japanese chestnut - Castanea crenata and the European chestnut - Castanea sativa. The aim of this innovative program was to create new hybrid varieties with improved traits and characteristics, but especially with resistance to the soil-borne pathogen Phytophthora cinnamomi, which causes root rot. Japanese chestnuts are more resistant to Phytophthora, but are less suitable as rootstocks because they are susceptible to cold damage and have a smaller trunk diameter than the more robust Castanea sativa. Although their fruits are large, their taste qualities lag significantly behind those of European chestnuts.

This program initially used natural hybrids of Japanese and European chestnuts, that is, hybrids that were created by open pollination between individual trees. The result was the Bournette and Précoce Migoule cultivars, resistant to Phytophthora root rot and suitable for fruit production. In addition, the Marsol and Maraval cultivars recommended as rootstocks were developed. The Marigoule cultivar, another natural hybrid from this breeding program, was initially intended for afforestation, then used as a rootstock and is currently recommended for chestnut production.

The breeding program then focused on controlled hybridization, that is, the maternal and paternal components were placed in an isolator - a greenhouse. Here, controlled pollination took place, which allowed the breeding of cultivars such as Bouche de Bétizac, which is resistant to Phytophthora root rot - Phytophthora cinnamomi, tolerant to bark cancer - Cryphonectria parasitica and, recently, it was found to be resistant to the pest Dryocosmus kuriphilus. At the same time, new rootstocks resistant to phytophthora root rot were created - Maridonne and Marlhac.

Moving the breeding program to Bordeaux

In 1971, the breeding program was placed at INRA Bordeaux. Here, breeding work was carried out over the following years, which provided hybrids more similar to the European species and which are now the basis of French chestnut production.

The breeding objectives in the development of rootstocks were:

  • to improve tolerance to phytophthora root rot compared to the European chestnut
  • to ensure medium to high growth vigor and adaptation to the French climate
  • to allow easy propagation by mound layering (also called stooling)


The breeding objectives for the development of the cultivars for chestnut production were:

  • to improve the size of the chestnuts compared to the European chestnut
  • to produce fruits that are easy to peel
  • to improve the quality of the chestnuts compared to the Japanese parent


Information, promotion, marketing...

In addition to providing planting material, it is important to continuously educate chestnut orchard owners to ensure that they have the necessary knowledge and skills to properly care for their chestnuts. This may include organizing seminars on pruning techniques, pest and disease control, and organic farming practices.

Thoughtful promotion of the consumption of chestnuts and chestnut products can help create demand for the crop and motivate farmers to invest in their orchards. This can be achieved through marketing campaigns, collaboration with chefs and food producers, and participation in local food events and farmers’ markets.

By combining good management practices with an ambitious breeding programme, we can work to halt the decline of Europe’s chestnut orchards and ensure the sustainability of this valuable crop. It is essential that we act now to preserve this magnificent tree and its delicious fruit for future generations.