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Why a Walnut planting?

THE WALNUT,  a crop of future

Overproduction of different species of fruit and the lack of profitability of farms, forced to seek alternatives to those lands that have fruit vocation.

The cultivation of walnut for nut production may be a valid alternative for areas with suitable conditions.


Production in trade in the world

The following data are from the Foreign Agricultural Service / USDA, and for the year 2010.

      Country                             Production                    Internal consumption

                                          (tm., en cáscara)                        (Tm.)

     Xina                                560.000                                   568.000

     USA                                396.400                                   162.500

     Ucraina                           100.000                                   157.700

     Turquia                             88.000                                   121.654

     EU-27                               66.000                                   157.000

     India                                  37.000                                    16.500

     Xile                                   32.500                                        -----


Other consuming countries, not producers, are: Russia: 36.500 Tm, Japan. 35,000 tonnes, Korea. 22,000 tons. Canada 17,500 MT., Etc.

The European producing countries are France, with 41,000 tons, Romania.. 38,000 Tm, Italy: 16,000 tons. Spain produces some 10,000 tonnes. (Source FAOSTAT / 2009).

U.S. It is the first exporter of new in the world, with 45% of the total (245,000 tons.), Followed by Ukraine (85,000 t.) Chile (28,900 tons.) EU-27 (22,900 t.), China (11,000 MT .), etc.

The main importers of new are: EU-27 (114,600 tons.), Turkey (42,000 tons.), Russia (36,500 t.), Japan (30,300 MT.), Etc. Among the European countries, the main importer are Germany , Spain and Italy.


Cultivation requirements

Walnut is a demanding plant. Filter requires a deep soil (moisture fears at the root) and. Accurate, depending on the variety, between 600 and 900 hours of cold in winter, to ensure acceptable production. Finally, study the different varieties available to ensure sprouting time than feared late frosts in the spring, which would freeze the buds of the year, which appear later flowers and fruits.

Abundant irrigation and fertilizer are needed. You really have to treat it as a fruit.



Classic varieties of French origin, are very late budding, adapted, therefore places with risk of spring frosts. The best known is the Franquette, great taste quality, but in a very slow start production and reduced production. Must be limited to cold areas, mountain, etc. and is very fussy about chill hours, to the extent not produce virtually any flower in very warm areas. It is a very good pollinator variety for varieties of California, for the male flowers appear late. Only occurs in terminal buds, limiting productivity. Other classic varieties of French origin, less interest are: Paris, Mayette, Round Montignies, cornea, Mabbot, etc.

A variety of French origin, very productive, high caliber and sprouting in middle age, is Lara. It has an important production side shoots. In our conditions it is very sensitive to bacterial. It has a good market as green walnut, for its earliness.

More recently the INRA in France, has obtained new varieties by hybridization. Fernette moment, it is an excellent pollinator of American varieties, introduced to the market in 1995 and 25-30 April sprouts and Fernor, also introduced in 1995, sprouting as Fernette and medium vigor, is a good choice to produce, in certain climates, it is insensitive to anthracnose and moderately to bacteriosi. Both varieties are crosses between Franquette and Lara.

In our climatic conditions are varieties Californian home (University of Davis in particular) the most desirable and almost the only currently planted.

Most of the old plantations in California, were of the Hartley and Serr varieties. Other ancient varieties, Payne, Pedro, approach, Friend, Come, Boy, have been dutifully upgraded to the newest, described below.

Hartley was discovered in 1915 Ramification 20 days after Serr, but has only a 10% lateral flowering, which gives low production and entry into production is slow. The nut is of excellent quality. A variety of sites at risk of frost.

Serr is a plant of great vigor. Has a 50% yield in lateral buds. It is very early sprouting, therefore has a high risk of spring frosts. It is very productive and rapid entry into production. The harvest is very early, which makes better use of equipment for harvesting and post harvest.

More recently introduced varieties are now planted, from hybridizations made ​​for rapid entry into production, high production and high quality of the nut.

Chandler, introduced in 1979 by the University of California, has 90% production side shoots, for high productivity, medium vigor, sprouting 15 days after Serr, excellent grain color and very rapid entry into production. Late harvest.

Howard, 80/90% of production in lateral bud sprouting 15 days after Serr, moderately vigorous, very productive, excellent fruit quality and harvest a few days before Chandler.

Tulare, recently introduced, is a large diameter walnut tree very vigorously. Very productive, sprouts 15 days after Serr and late harvest.

Forde (UC95-26-37) introduced recently as 2004 by the University of California, from a cross made ​​in 1995, of interest to harvest 10 days before Chandler. It has an average force between Gillet and Sexton. Budding is five days before Chandler.

Gillet (UC95-22-26) also can harvest 10 to 20 days before Chandler. Budding is also about 10 days before Chandler. Among his relatives tea Chico.

Sexton (UC90-31-10). From the same date of introduction, you can harvest a week before Chandler and has a 100% yield in lateral buds and is very productive in young trees, because a rapid entry into production. It has a high density of branches, so it requires a strong pruning, the early years. Comes from a cross of the year 1990, and among its relatives Chandler.

Ivanhoe is also a variety of very recent introduction. Has 100% production in lateral buds and can be harvested one month before Chandler, while Serr. Requires a very dry climate.

Of great interest for its earliness. You have to check the adaptation to our climate.



Traditionally, the walnut is grafted onto rootstock, from sowing seeds of Juglans Regia. It is not the same in USA, they have traditionally used black walnut, Juglans hindsii normally and mainly natural hybrids between this and Juglans regia, called Paradox. The European black walnut, Juglans nigra, and American, J. Hindsi have the advantage of resistance to root diseases, especially fungi Phytophthora species. But they have a serious problem, which is their sensitivity to CRLV virus (Cherry leafroll virus) due to Blackline, causing an incompatibility between standing and variety, always J. Regia, necrotizing graft area, killing the plant.

In fact, right now, the rootstock, from seed is the most used in plantations.

Cite a number of new rootstocks, already available, that have been selected to bring some improvement, in terms of vigor, adaptation to calcareous soils, resistance to root diseases, nematodes, etc.

Originally from france:

  • Mj209 x Ra, (J.major x regia) very vigorous and adapted to alkaline soils
  • Ng23 x Ra, better adpated to acid soils

Originally from USA

    • Vlach, a clonal paradox, micropropagated
    • VX211, tolerant to nematodes and moderately tolerant to Phytophtora. It is a hybrid of Paradox x J.Regia, very vigorous, light resistance to nematodes and easy transplant
    • RX1, is a hybrid of Juglans microcarpa (black noguer Texas) x J.Regia. Short vigor, highly resistant to Phytophthora and easy transplant;

It's on study the use of Pterocarya stenoptera, xina originlly, which has a high resistance to Phytophthora, but has difficulty with certain varieties grafting and you do not have enough experience

New rootstocks are being studied to achieve mainly resistance to root diseases and a good vigor


We have said that walnut is a demanding plant in sun and water. Need a filter and deep soil and abundant irrigation. Planting nut trees on marginal lands, leading to failure. The investment for planting is important. To do soil analysis to determine the necessary fertilizer and especially if you have to correct the ground and be guaranteed a minimum contribution of 1,200 cubic meters per hectare per month during the summer. Special irrigation systems: underground, tapes, etc., they can save water, but be careful in the calculation, because a mistake can be fatal.

The planting varies according to the chosen varieties and soil fertility. Between rows is undesirable lowering of 8 meters, to facilitate handling of the crop. Among trees may be 5 to 7 meters. This represents between 200 and 250 trees / ha. In varieties like Serr or Tulare, must reach 8 x 8 or 8 x 9 meters. Wide framework is also needed for the Hartley strain, which is ill adapted to the training center axis, the lack of dominance of the shaft, which is quickly overtaken by the lateral branches and tends to form a glass. For new varieties best adapted form is central, structured or unstructured, allowing rapid entry into production and facilitates mechanical pruning adulthood. The first few years pruning necessary training manual, which represents few hours per Ha., But it is essential.

A rule must always keep in mind: If you can not get no sun nut production. Therefore we must clarify the branches, leaving space between them for good lighting.

We consider the super-intensive plantations have not been successful. Walnut is a large plant that quickly occupies the space you need. If you do not have enough wins is a good height and shaded. In fact, the old plantations in California with Serr variety or Hartley, planting frames are 10 x 10 to 12 x 12 meters, with excellent productions.

Finally you have to make some comments concerning the size of farms. Walnut farms require little labor. A person can live quietly, from 25 to 50 hectares., As mechanization of irrigation on everything. You will need help in the harvest and slightly, it may be in pruning. The harvest is mechanized, with different types of machine. Some may be enough for a plantation of up to 30 hectares. Plantations older, 50 to 100 hectares. machinery require greater capacity and higher price. Overall harvesting equipment consists of a vibrator (as used by almonds or olives) and a collector. The nuts should be dried soon after harvest and be washed and spend a top pick. We need, therefore, a drying system, usually with hot air, provided the expected harvest. In France, a dryer capacity, the 25/30% of production is calculated. Consider that normally work with a variety Franquette, dry and difficult environments usually very humid. In our conditions, experience says that 15/20% of capacity is sufficient in normal years. And even if it can be lowered Planting varieties with staggered harvest.

On smaller plantations is very important to study the possibility of sharing equipment collection and treatment, as it is a major investment, it is not used more than a few days.