By Jaume Lordan, Xavi Garanto, Xavi Farré, Neus Mas, Gemma Echevarría and Ignasi Iglesias.

The mountain fruit growing project in Catalonia started in 2009 when IRTA (Institute of Agrifood Research and Technology) and ADRR (Association for the Development of the Romanesque Ribagorça) signed the first collaboration agreement; and kept going later on with IRTA and the Ministry of Agriculture, Livestock, Fisheries and Food of the Catalan government.

This was a pioneering initiative, as there were no references to these fruit tree orchards in mountain areas close to 1,000 m of altitude. That step forward made possible to determine the climatic characteristics, the potential and aptitude of the mountain areas for this kind of crops, contributing and transferring all the generated knowledge to the industry.

In 2018, there were more than 70 ha of commercial apple orchards planted in the Catalan Pyrenees. These orchards follow two models of exploitation: the first corresponds to consolidated companies that have been growing apples historically in the fruitful zone of Lleida, and they wanted to diversify his production in order to optimize their postharvest structures. In this model, companies already have their brands and their own commercial circuits for both domestic and export markets. The second model corresponds to that of small farm owners, usually with no experience in horticulture, or almost altruistically ceded to the last farmers present in the various mountain areas, where livestock has always been a traditional activity linked to the territory but is in clear decline; the more pronounced the more impact tourism has had.

In this case, these are small orchards close to villages and generally have good accessibility with optimal soil conditions and a good suitability for apple production. The owners are engaged in the production as part-time job, as a complementary activity and income, similar to the prevailing model in South Tyrol or Trentino in northern Italy. Due to the smaller dimensions of these orchards, and the non-connection with pre-existing commercial channels, this type of production is focused on local markets that are able to assess this type of production of quality, proximity and linked to the territory and its economic development.

The production technology of the different orchards is similar in terms of their design and training systems. It corresponds to intensive orchards with dwarfing rootstocks, central axis systems and planting densities of 2,000 to 3,000 trees per hectare, at trees spacings of 3.4-4 m between lines and 0.8-1.2 m between trees. Irrigation and fertilization are located at high frequency, with automated irrigation monitoring systems. In most of the orchards there is sprinkler irrigation and all have anti-hail nets.

From the results obtained from the experimental activities carried out in the framework of the mountain fruit growing program, there are some limiting factors to take into consideration:

• There is low land availability suitable to grow apple trees, with smaller plots, which are less suitable for mechanization and more difficult to access.
• Lower availability of irrigation water.
• The risk of spring frosts increases in regard to what usually happens in the plain areas like Lleida. The risk of autumn frosts is also higher in late varieties, which limits their planting.
• Higher risk of hail, reaching 100% in areas above 500 m altitude, although it is usually smaller.
• The vegetative period is reduced linearly with altitude, which is a limitation for late harvest varieties at altitudes above 1,100 m. Fruit size tends to be smaller for the ‘Gala’ group varieties, and the higher the altitude, the higher the incidence.
• Higher production costs.
• Lack of experienced growers.

As favorable qualities, we may consider:

• Areas with very low crop establishment. Therefore, lower incidence of pests and diseases in terms of traditional and crowded cultivation areas.
• Greater ease for the integrated and organic production, especially with scab resistant varieties which tend to have lower number of treatments.
• Flowering and harvesting dates are delayed between 3 and 4 weeks in relation to what is observed in the fruit-growing area of Lleida, which indirectly enhances fruit color.
• Greater fruit set with respect to the plain, so thinning strategies need to be more vigorous, especially in varieties of more limited fruit size such as ‘Gala’.
• Environmental conditions, in particular temperatures, benefit not just fruit color but they also improve fruit quality such as texture, juiciness and crunchiness.
• Maturation is slower and with a wider harvest window.
• Sugar content and acidity is higher.
• At the same state of maturation, firmness increases by about 1 kg for all the varieties, except for the late ones like ‘Fuji’.
• Yield is similar to those obtained in the plain areas.
• Lower water footprint due to lower evapotranspiration.

The mountainous orography that modifies the weather conditions implies higher environmental humidity, lower temperatures, and ultimately less stressful conditions for the trees. The results obtained allow us to state that the production of high-altitude apple, due to its characteristics of differential quality, is a feasible alternative and an interesting complementarity with traditional fruit-growing areas. However; its sustainability will depend if it is able to implement an efficient commercial structure, adding value to this type of production that implies higher costs in comparison with the plain areas. All these positive aspects are even more evident in the case of mountain and organic production directed to local markets. To sum up, mountain apple orchards show no less significant risks, but in return, provide a differentiated product from what our country is highly deficient.

Authors belong to: IRTA (Institut de Recerca i Tecnologia Agroalimentàries), FruitCentre – Lleida; Observatori Varietats Ribagorçanes and Agromillora Group.