Technologic problems to face when establishing walnut in new cold areas: the experience in the southern hemisphere

Abstract

In south Argentina, mainly in the Patagonian region, high-density walnuts are planted. The diversity of the soils of the region, the heterogeneity of the plants available on the market and the limited use and tradition of this crop, which leads to the implementation of technologies from many different origins and variable success, make it necessary to recommend integral management strategies, as proposed in the conference.

A productive project considering the implementation of new walnut plantations requires a complete analysis based on previous studies in order to assure the three basis of a successful enterprise: -Choose an adequate site in order to develop the plantation. -Select the best vegetal material available. -Use the proper management technologies for that crop.

The “site” must gather all those conditions in which trees can unrestrictedly develop and produce abundant, high-quality and early harvests. Climate will be determinant: in temperate-cold weathers the risk of frosts and the strategies to minimize its harmful effects will be the factor of highest risk to take into account.

The choice of the site also involves the study of the soil’s aptitude to be cultivated with a high requirement species such as walnut, considering its physical and chemical conditions. A topographic study is also important, since it will affect –among others – the formation of micro-climates.

The quality of the young plants is determinant to start properly the enterprise, and to achieve that some characteristics must be considered, such as: anatomy (vigor, root system), sanitary status (plague and disease free) and genetic type (choose proper cultivars for the chosen site, considering sprouting dates).

In regards to proper management technologies, it is essential to watch out every step of the project: pre-planting (soil preparation, nursery plant management, planting design, etc.), planting (plantation techniques, fertilization, tutoring, etc.) and post-planting (irrigation, sanitary cares, pruning, etc.). On the whole, all these practices certainly need to be locally improved and tested in the particular situation of the site-plant-management interaction proposed.