Gardening

Walnut varieties produced on Prydnistrovska experiment station for sale

Characteristics

Yarovskyy

Klyshkovskyy

Chernivetskyy 1

Bukovynskyy 2

Differs

Poor tree growth

Early maturation, crop yield,

attractive fruit

Early maturation, high market quality of fruit, crop yield,

attractive fruit

Early maturation, crop yield,

attractive fruit

Tree

Crown diameter 8-9м

Tall

Forms large crown

Forms large crown

Sensitivity to diseases

Low-sensitive to diseases

Low-sensitive

Low-sensitive

Low-sensitive

Blossom

Mid May

Early May

Mid May

Mid May

Fruiting

Average crop yield from the tree 30-35 kg

Average crop yield from the uterine tree 61 kg

Fructifies on the 2-3 year of planting,

average crop yield from the tree 44 kg

Average crop yield from the uterine tree – 75 kg

Fruit

Egg-shaped,

Mid-size, weight 10,9-11,8g.

Ellipse-shaped, mid-size,

weight 10,9-13,3g.Crop yield – mid September

Round, mid-size, weight 10,6-12,8 g. Crop yield – mid September

Ellipse-shaped, big, weight 13,7-15,4g

Shell

Thin,s-1-1,1mm almost smooth, easy to crack

s-1-1,1 mm

almost smooth, easy to crack

Thin,s-0,9 mm almost smooth, easy to crack

Medium,s-1,3 mm almost smooth, easy to crack

Kernel

50-53% from total weight, very light, tasty, easy to withdraw in whole

48,9-50% from total weight, light, tasty

50,7-54,6% from total weight, light, tasty, easy to withdraw in whole

48,1-49,2% from total weight, light, tasty, easy to withdraw in whole

Fat content,%

68,2-70,7

67,3-69,6

68,4-70,8

68,1-70,5

Protein content,%

12-15,7

12,4-15,9

15,9-16,9

15-17,5

Sugar content,%

7,9-11,7

8,9-13,8

7-9,4

7,2-10,2

Characteristics

Bukovynska bomba

Bukovynskyy 1

Prydnistrovskyy

Prykarpatskyy

Toporovskyy

Differs

Attractive fruit and  pleasant taste

High and stable crop yield

High and stable crop yield

High and stable crop yield

High and stable crop yield

Tree

Tall

Forms medium crown

Forms huge crown

Forms large rounded crown

Forms large rounded crown

Sensitivity to diseases

Relatively resistant

Relatively resistant

Low-sensitive

Relatively resistant

Low-sensitive to diseases

Blossom

Mid May р

Late May

Mid May

Mid May

Late May

Fruiting

Average crop yield from the uterine tree – 34 kg

Average crop yield from the uterine tree – 75 kg

Average crop yield from the uterine tree – 75 kg

Average crop yield from the uterine tree – 70 kg

Average crop yield from the uterine tree – 70 kg

Fruit

Round, circular-shaped, big, weight 17,4-18,2g.

Crop yield – late September – early November

Mid-size (10,1-14,1 g), round. Crop yield – mid September

Mid-size (10,8-12,8 g), round. Crop yield – the beginning of the second decade of September

Mid-size (11,2-13,5 g), round, Crop yield – late September

Mid-size (10,6-12 g), elongated ellipse-shaped

Shell

Thin,s-1,5mm,

easy to crack

Thin, easy to crack

Thin, firm.

Kernel is separated easily from shell

Thin, firm.

Kernel is separated easily from shell

Firm, inner membranes are thin, easy to crack

Kernel

47,5-48,2% from total weight, light, tasty, easy to withdraw in whole

52,4% from total weight, light, tasty, easy to withdraw in whole

52,88-53,7% from total weight, light, tasty

50-51,5%

Kernel is separated easily from shell

49,8-54%

Kernel is separated easily in whole or in halves

Fat content,%

67,3-69,6

70,12-73,13

69,59-72%

67,97-72,94%

68,67-74,85%

Protein content,%

12,4-15,9

14,04-15,93

14,98-15,22%

12,68-14,58%

11,77-13,98%

Sugar content,%

8,9-13,8

7,15-8,84%

7,49-9,72%

6,99-12,55%

7,66-13,22%

Walnut trees are long-lived enough and reach large sizes under favorable climatic conditions. They can reach the age of 100 years and more, their height up to 15-16m is quite usual fact. In Ukraine the industrial walnut gardens formation is practicable reality. Almost in every region there are tens of thousands of soil hectares which are suitable for walnut plantations. But at present these soils lie fallow. The problem can be solved if qualitative planting material (namely grafted walnut seedlings) is available.

To start preparations for planting walnuts are kept in cool enough and dry place. 12-14 weeks before planting nuts are placed in box with wet sand where they are hold at 7°C. In is very important to watch over the sand humidity. Cellar or vault will be rather good for optimal temperature and humidity conditions retention.

The important thing is not only to know how to couch walnut. Sometimes the tree grown from the planted walnut sapling gives more qualitative fruit, than the ones used for planting and vice versa. And to find out the result one should wait for years.

Walnuts sprout up by themselves during warm winter. Seeds fall from the trees, keep perfectly in soil and sprout up as young seedlings in spring.

Well-developed annual seedlings (diameter near root collar is 12 mm and height is 15-20 cm) are used as wildings when grafting is done at closed soil. Taproot and its main branching should be completely healthy, without any damage and signs of rotting. Ripe sprouts (length is 30 cm and thickness is 7 mm) are used as grafts.

If the grafting is done in March-April, sprouts can be procured 20-30 days before commencement of works. In this case they are kept in wet sawdust or sand. The ends of sprouts are covered with grafting clay or pitch. In summer they are prepared directly before inoculation to get bark easily separated from walnut wood.

The best time for this process is till the middle of summer. In August the bark is separated quite difficult from walnut wood.  The old and middle age (30-50 years) trees give too little grafts suitable for grafting.

Because of the existing of strong probability to get not the same product as one expects, seedlings obtained from walnut seeds, as a rule, are used as wildings. To get the guaranteed result, the sprig of fruitful walnut is engrafted on wilding.

At the end of April or at the beginning of May walnuts are taken out the cellar and planted at open soils. They are set edgewise (in this case roots at once begin to grow in the right direction after the emergence of seedlings) in prepared earlier pits with the depth up to ten centimeters.

In a year walnut can be implanted on its appropriate location. Seedlings obtained from walnut seeds are better to plant on the locations which have enough shade or some dust protection, for example, near the road.

For the last years in many countries the new technology of industrial production of walnut grafted saplings has been developed with the new method of desk grafting during winter time. This technology has a lot of advantages in comparison with inoculation in gardens and in the first place it is developed to increase dramatically the production of high quality saplings.

In contrast to inoculation, desk grafting is produced under controlled temperature and humidity conditions. It provides the high interest of acclimation rate and considerable productivity.

The acclimation rate grew up to 80-82% from the total number of grafted saplings because of modern equipment usage, new method of desk grafting with the use of fitting chambers and thermal stratification chambers.

The peculiarity of this method is the high interest of acclimation rate, which is reached with high precision of temperature and humidity keeping and carbon dioxide stream disposal.

Such method of grafting makes it possible to generate up to 300 000 sapling per season.

Environmental conditions influence on walnut growth and fruiting  

Light requirements. Walnut is one of the most light-requiring cultures and it can productively fruit on condition of well-illuminated crown of the tree. When slight darkening of trees, caused by pruning absence, only sprout tops are grown. As a result, the crown is formed with bare branches and immature leaves. The harvest from such tree is small and is formed on the crown periphery. Recommended scheme of planting is 8Х8м with compulsory pruning, the crown should be 3-4 levels of height.

Soil and relief requirements. Walnut grows well almost on all varieties of soil and relief. Trees are unproductive, they grow too slowly and freeze slightly only on bogged, badly drained and washed heavily soils.

The most productively walnut grows on black earth, loess-like deep soils.

Humidity requirements. Walnut has strong deeply penetrating root system up to 30 m that provides usage of humidity from deeper soil level. Walnut is hygrophilous culture and in case of frequent watering it can grow up to 2 m per year that is very important during the first years after planting. Regular watering makes it possible to get the first harvest on the fourth year and total fruiting on the eighth year.

Humidity requirements can be observed mostly during the first 1-1,5 months of vegetation (May-June), when the harvest forms and the growth processes are more intensively.

Heating requirements and resistance to cold. This culture refers to heat-loving plants and it can grow in regions where the accumulated active temperatures raise up to 10 °C (in May-June the temperature is much higher almost in all regions). The scientific research showed that the high level of farming equipment and sufficient humidity provision can raise the walnut resistance to cold.

Harvest and storage.

China and USA (California) are the largest producers of walnuts among different countries around the world. The annual gross yield of walnuts reaches 46% of the world level. Ukraine takes the fifth place by gross yield of walnuts in the world. In Ukraine for the last two years industrial walnut gardens areas have expanded up to 2800 hectares and this number keeps growing.

Walnuts are gathered in September-October, just after their falling. The green pericarp is removed from gathered walnuts; after that it is dried in the sun or in special drying chambers at a certain temperature which should be below 60°C. The humidity of dried walnuts shouldn’t exceed 10%. Walnuts are sorted with the help of calibration machines. Later their quality is checked. Walnuts are packed in paper or fabric bags weighing 30-50 kilograms. Period of storage is 2-3 years.

Walnut leaves are gathered in spring and at the beginning of summer. The compulsory condition is the dry weather. They are picked and packed in bags or baskets. After that leaves are spread on the paper or light fabric with a thin layer and dried in the sun. Darkened leaves are thrown away. As a result, the total percentage of dry substance accounts for 23-25%.

Walnuts are stored in dry cool places. Pericarps are picked by fruit stocking. They are cut in two; damaged parts are thrown away. Later they are dried at 30-40°C. As a result, the total percentage of dry substance accounts for 20%.

Raw material is packed in bags and stored in regular manner.

Walnut crown formation.

Efficiency pruning has significant importance for better adaptation of trees after replanting, walnut crown formation and retention, stimulation fruiting at the expense of useless and dead branches removal. Cutting walnut branches begins from the second year. As a result, the stamp is left at a height of 0,9-1,1m. To protect saplings from the first autumn frosts, their growth is held up on the first year of transplanting (at the end of August). The next three-four years depends on the soil and walnut quality potential, the tree crown is shaped in the form of axis or cube.

Fertilization  

It is a fact that walnut takes a lot of mineral elements from the soil, so the lack of them should be supplied every year. It is always necessary to watch over the level of acid soils, which should be within limits from neutral to alkalescent. Phosphoric-potash fertilizers forward the walnut fruiting, but they should be supplied on the root level. Nitrogen has significant importance for intensive vegetation. However, nitrogen fertilizers applying in walnut garden should be carried out very carefully; otherwise they will be the reason of bacteriosis development. Nitrogen fertilizers should not be applied for two-three years during the period of the walnut fruiting beginning.

Usually the rate of mineral elements applying in walnut gardens is a little higher than the rate in other fruit tree gardens. For one mediaeval tree (30-50 years) one should apply 10-12 kg of ammonium sulphate or 6-7 kg of ammonium nitrate, 9-10 kg of superphosphate, 2-3 kg of potassium. Phosphoric and potash fertilizers are applied before autumn fallowing, and nitrogen fertilizers are applied in spring, before cultivation. The soil should be mellowed regularly for humidity retention.

Disease and pest control

The most harmful walnut diseases are bacteriosis, leaf blotch or late blight disease.

Bacteriosis (Xanthоmonаs cаmpestris px juglandis) is the most widely-spread walnut disease, and there are no walnut varieties persistent to it in world practice. This disease affects all overground walnut organs: buds, leaves, male and female blooms.

Agrotechnical measures have tremendous significance to protect trees from this disease. These protective measures are directed at leaves collection and damaged branches burning. Among chemical weed and pest killers the most effective are preparations containing copper – blue vitriol, copper oxide and etc. Remember, preparation solution processing should be carried out before the bloom infection begins.