Agrotechnology is the foundation of growing walnuts

Planting a walnut tree is not difficult, but certain details must be observed

Here's how the planting process looks like:

Choosing a planting scheme

(01)

It depends on the type of fruiting of the chosen seedling, which affects the size of the crown. The quality of the soil and irrigation are also important. There are planting schemes that provide for tree thinning in the future. This will help reduce the payback period but requires more complex agrotechnology and future land clearing costs

Marking and preparation for planting

(02)

It is necessary to determine the places for digging holes for planting. The size of the planting pits is usually 60 cm x 60 cm x 60 cm (length/width/depth). Before planting, it is necessary to carefully whitewash the seedling for the entire length of the aboveground part

Planting

(03)

Put 700 g of mineral fertilizer (ammonium phosphate or any NPK with a nitrogen content of 5−8%) at the bottom of the pit. It is better to place it along the circumference of the pit so that the roots grow horizontally. Then add a top layer of soil 25 cm and 8 kg of manure.

To plant, make a small mound and spread the roots. Fill with good soil and fresh straw manure on top with a width of 20 cm

Watering

(04)

Water the planting holes generously, using at least 20 liters of water

Staking

(05)

When planting, it is usually recommended to use a wooden pole with a height of 2 meters and a diameter of 4 cm as a support. We use a bamboo pole 210 cm long and 12−14 mm in diameter. We stick it in next to the trunk after planting.

A week after planting, an eight-shaped tie is made in two places. It is better to use a 5 mm cotton tape for this — this is a proven option, so the walnut resists wind gusts at any sail of the crown and grows with a straight trunk

Planting schemes

Planting schemes used are 10x12 (83 trees/ha), 12x12 (70 trees/ha), and 12x14 (60 trees/ha)

Standard orchard

The planting scheme is of crucial importance for the future laying of an industrial orchard. And it depends primarily on the type of your future garden — whether it will be a standard or intensive one

Uses traditional varieties that have an upper (apical) type of fruiting. These are usually large trees up to 30 m high. They are less demanding, relatively resistant to diseases and lack of moisture, and not so demanding in the use of agrochemicals

Intensive Orchard

Planting schemes used are 7x8 (178 trees/ha), and 8x10 (125 trees/ha)

An orchard planted using lateral fruiting varieties of walnut. These trees bear fruit all along the branches, and their size is significantly smaller, allowing for denser plantings

About Planting

Intensive plantings are chosen to increase yield per hectare and, correspondingly, reduce the payback period of investments. But this works only in theory. In practice, they are extremely demanding of agricultural technology, require drip irrigation and intensive use of agrochemicals.

Nevertheless, in the Baltic region, standard orchards can be made more productive. To do this, we recommend using varieties and forms that exhibit lateral fruiting by 30−50%. Such hybrids can be planted in an 8×10 scheme, and we offer them for order today

They require fertilization throughout the entire growing season and first-class planting material. The geographic region of cultivation is also essential for making a decision — such orchards grow better in countries with a warmer climate and a sum of active temperatures.

Walnut Crown Formation

To obtain a productive walnut tree, the seedling must be properly formed.

The tree crown is formed in two stages: formation of the trunk and formation of the scaffold branches. We recommend making the height of the trunk at 1.5 meters. If you plan to do mechanical harvesting with a shaker in the future, you can increase the height of the trunk to 1.8 meters.

To lay the foundation for a good trunk in the first season of vegetation, green operations in the form of pinching the top of the lateral shoots should be done, allowing the leader to grow. The leader is the strongest shoot that you choose yourself.

At the end of the season, all shoots with pinching are removed, leaving only one vertical branch — this is the very leader and future trunk of the tree. If the height of the leader is less than 1.5 meters, green operations are repeated in the second year of vegetation. The rate of growth of one-year shoots in different regions varies and depends on many factors: the quality of planting material, soil, mineral nutrition, the use of plant protection products, and of course, moisture.

After forming the trunk, the formation of the scaffold branches of the first and in the future, the second and third tiers, begins on the third year

Useful videos on the formation of the crown and trunk:

The main diseases and pests of walnut tree, and methods of combating them

Diseases of the walnut tree can arise for several reasons: due to lack of light, soil poverty, improper care, close proximity of groundwater, excess moisture, and late spring frosts

The list of walnut diseases is very wide, but the most common include:

Bacteriosis

White spotting

Brown spotting

Walnut diseases

Small round brown spots form on the leaves and then eventually turn gray with a wide brown border. On leaf stalks, they are elongated and dark brown, on the leaf blade itself, they are black. Affected leaves turn brown and fall prematurely.

One of the most widespread and hazardous diseases of the walnut tree in all regions of its cultivation. It affects leaves, young fruit, and shoots

Brown spotting (Marssonina blight or Marssonina leaf spot)

On the fruits, dark brown spots first appear on the husks. The affected tissues of the fruits lag in growth, and deep wounds form on them. The fruits dry out, the weight of the kernel is lost due to dehydration, some of them fall prematurely. Rot of the kernel can be observed, and sulfur-yellow ulcers form on the diseased shoots.

Plants affected by Marssonina blight are exhausted during the summer, enter the winter weakened, and freeze.
The percentage of fruit bud formation decreases in them

Disease agent:

The fungus Marssonina juglandis (Lib.) Magn. It has two stages of development: conidial, which allows it to spread during the summer, and ascus. It overwinters in fallen leaves and in affected shoots

Recommended preventive and treatment measures:

To restrain the development of the disease during the growing season, 2−3 treatments with a 1% Bordeaux mixture are carried out as a preventive measure. In case of an outbreak of the disease, a systemic fungicide Luna experience is used, with 1−2 treatments conducted at an interval of 10−15 days

The disease affects all above-ground parts of the tree: buds, leaves and their petioles, male and female flowers, one- and two-year-old branches, shoot tips, and fruits at various stages of development. Large black spots form on the leaves, spreading along the veins. The leaves become deformed, turn black due to the merging of the spots, and fall off. On non-woody shoots, the disease manifests itself in the form of elongated brown spots.

Bacteriosis

In years with favorable conditions for the development of the disease (rainy weather), up to 90% of the uterine (female) flowers are destroyed, and the trees practically remain without harvest. Infected young fruits fall off. Later, the damage can lead to a deterioration in the quality of nuts.

Disease agent:

The bacterium Xanthomonas campestris pv. juglandis. It can penetrate the core of young fruits, causing rot. It overwinters on the bark of damaged trees.

Recommended prevention and treatment measures:

For prevention, treatment with copper-based solutions should be carried out before the onset of bacterial infection of flowers and during the period of young fruit setting. The first spraying is carried out with a 3% Bordeaux mixture or 1% urea solution. The second spraying is done 15−20 days after flowering with a 1% Bordeaux mixture and 0.3−0.4% urea solution.

For the treatment of already existing bacteriosis, systemic preparations are used, which are absorbed by the plant, penetrate the tissues, and work for 2−3 weeks after treatment. Unlike contact preparations, they are more effective.

This disease affects the leaves. The first signs appear in the middle of May: a waxy coating in the form of spots, up to 2 cm in size, is formed on the underside of the leaves, limited by the veins. At first, these spots are pale green, slightly wrinkled, and over time they turn white.

White spotting

The tissues of the leaves in the affected areas are pale green and convex. Usually, the spots are scattered throughout the leaf blade, but they can also be located along the vein of the leaf. The affected tissues of the leaf die off, which often leads to its death.

Disease agent:

The fungus Microstroma juglandis Sacc. It belongs to parasitic fungi, characterized by colorless branching mycelium, and causes hypertrophy of the affected tissues. It overwinters on fallen leaves.

Recommended prevention and treatment measures:

At the first signs (the beginning of the spread of the infection) — spray the affected plants with copper preparations. Depending on the intensity of the further development of the disease, one or two more treatments are carried out at an interval of 20−25 days.

About pests

Another serious pest for walnut plantations are animals (deer, rabbits, and small rodents). They damage the young bark of seedlings by gnawing on them in winter.

It is recommended to fence the planting area completely. For this purpose, you can use a self-twisting mesh to protect against rabbits and small rodents, as we do in the nursery. Such fencing effectively protects against animals and does not harm the tree