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The historical homeland of blueberries is North America. The habitat of the tall shrub is floodplains and wetlands. The wild species formed the basis for a large number of dessert varieties with good yields and high gastronomic appreciation. Denis Blue blueberries are the result of New Zealand selection; the priority in the work was to create a variety adapted to cold climatic conditions. In Russia, the crop is grown throughout the European part of the country; in 2013, Denis Blue blueberries were included in the State Register.
Description of blueberry variety Deniz blue
Blueberry variety Denis Blue is a perennial deciduous shrub with a spherical shape; by the age of six it grows up to 1.5 meters. Frost-resistant culture successfully resists temperatures dropping to -40 0C, freezing of shoots is rarely observed. The shrub is not afraid of sudden changes in temperature in the spring, because...Blueberries bloom later, after possible return frosts.
Blueberries are grown in Siberia, the Urals, the central zone and the Moscow region for berries and as a design element in ornamental gardening. Denis Blue looks aesthetically pleasing from the moment of flowering until the autumn change of leaf color. In September, the crown becomes bright yellow, then the leaves take on a burgundy hue and do not fall off until frost sets in. The bush is densely branched, young shoots grow quickly and in huge numbers.
External description of the garden blueberry variety Denis Blue:
- The stems are thin, erect, with slightly drooping tops, rigid, flexible, and completely woody. The bark is smooth, light brown with a gray tint. The shrub is round in shape, has grown in width, diameter is 1.3 m.
- Denis Blue blueberry is densely leafy, the leaf blade is 3-3.5 cm long, obovate, lanceolate, opposite arrangement. The surface is smooth, with a network of veins, glossy, green. The cuttings are hard, of medium volume, long, dark beige.
- Flowering is abundant, the flowers are light pink, small, pitcher-shaped, 6-10 pieces are formed on the fruit raceme.
The root system is poorly developed, located close to the surface, the roots are thin, fibrous, and cannot independently provide Denis Blue blueberries with nutrients. The peculiarity of the culture is a way to obtain the necessary microelements; it consists of symbiosis with the mycelium of the fungus. Mycorrhiza provides vital activity for both the fungus and the plant.
Features of fruiting
The blueberry variety Denis Blue is a mid-season variety; the bush blooms in June and the berries are picked in the second half of August.Ripening is uniform, the clusters are located on the outer part of the stems, easily accessible for collecting fruits. Denis Blue blueberries can produce their first fruits in the third year of the growing season. The flowers form single ones; they are not left on the bush, since the productivity of the young plant is low.
Full fruiting occurs in 5-6 years, the variety’s yield is high, 6-8 kg of berries are harvested from one bush. Blueberries are dioecious plants, produce male and female flowers, and are cross-pollinated. The variety can do without pollinators, but in this case the yield decreases. For a high fruiting rate, it is recommended to plant varieties with simultaneous flowering next to Denis Blue blueberries; Bluecrop and Northland blueberries are suitable as a pollinator.
The berries of the Denis Blue variety are the same size, color at the stage of technical ripeness, but acquire taste after 3 weeks. The fruits are not prone to shedding, are well attached to the stalk, and are pulled off dry. They do not bake in the sun with sufficient watering. In case of moisture deficiency, they grow smaller, sour, loose, and lose their shape.
Description of blueberry fruits of the Denis Blue variety (shown in the photo):
- shape in the form of a circle compressed on both sides, weight – 1.9 g, diameter – 18 mm;
- the peel is strong, elastic, thin;
- The blueberry is smooth, with a small depression on top with a jagged receptacle;
- The color is dark blue with a silvery waxy coating; the ripe berry has a juicy, dense structure, light purple flesh.
The presence of acid in the taste is minimal, the berry of the variety is sweet, with a light aroma. Blueberries are consumed fresh, processed into juice, wine is produced, and jam is made. They do not lose their taste after freezing.The Denis Blue variety is suitable for commercial cultivation, the fruits are stored for about 7 days, transported in a refrigerator with a temperature not exceeding +5 0C.
Advantages and disadvantages
According to gardeners, the blueberry variety Deniz blue has a number of advantages:
- frost resistance;
- high yield;
- good taste;
- versatility in use;
- simple agricultural technology;
- duration of fruiting.
Disadvantages include low drought resistance, intensive formation of young shoots, and the shrub requires pruning. Average resistance to infection.
Features of reproduction
Blueberries of the Denis Blue variety reproduce only vegetatively:
- By cuttings. The material is harvested in the spring from last year's shoots. The cuttings are placed in a nutrient substrate at an angle of 450, watered, covered for the winter, planted next year in the fall.
- Dividing the bush. The work is carried out after fruiting; shrubs no younger than 4 years old are taken for division.
- By layering. In the spring, before the sap flows, the lower branch is dug in, and the following spring, plots are cut and planted on the site.
A prerequisite for independent propagation is that the top layer of soil should not be allowed to dry out.
Planting and caring for blueberries Denise blue
If planting is carried out using self-grown material, blueberries are disinfected with a 5% manganese solution and the root is left in place for 4 hours. Then any growth stimulating drug is used, used in accordance with the instructions. If a purchased seedling is planted, it must be two years old without signs of mechanical or fungal damage.
Recommended timing
Blueberry variety Denis Blue is a frost-resistant representative of the species. Planting can be done in spring or autumn. In the first case, the timing depends on the climate, the main condition is that the soil warms up to +8 0C. For the middle zone, the approximate time for spring planting is early or mid-May. Autumn planting is carried out 1 month before the onset of frost, the survival rate of blueberries is high, this time is enough for the plant to take root.
Site selection and soil preparation
The blueberry variety Denis Blue does not tolerate even slight shading. Photosynthesis depends entirely on the amount of ultraviolet light. In the shade, vegetation slows down and productivity decreases. A suitable area for blueberries is an open, well-ventilated space (the plant is not afraid of drafts). A wetland or low-lying area will do. The composition of the soil should be acidic. The area is dug up, a nutrient substrate is prepared from peat, sawdust, pine needles, and sand.
Landing algorithm
A seedling purchased from a nursery with a closed root system is already equipped with mycelium. For self-grown material, buy fungal spores.
Landing sequence:
- Dig a hole with a diameter of 80*80 cm and a depth of 0.6 m.
- Pour ½ of the mixture onto the bottom and fungal spores on top.
- Place the blueberries in the center, carefully distribute the roots along the bottom, they should completely cover the area with the mycelium.
- Cover with the rest of the substrate and soil.
- Compact, water, mulch with sawdust mixed with peat or pine needles.
If several blueberry bushes are planted in one line, the interval between them is 1.5 m.
Growing and care
Proper planting and compliance with care recommendations will ensure normal growing season and high productivity for blueberries of the Denis Blue variety.Agricultural technology includes: timely watering, fertilizing and maintaining the necessary acidity of the soil.
Watering schedule
Blueberries of the Denis Blue variety are not a drought-resistant plant, so watering is required for the bush. The roots are located close to the surface, so the soil must be constantly moist. But excessive watering should not be allowed; excess moisture can cause root rot.
Watering is carried out in the morning and evening every other day. The daily norm is 5 liters. The frequency of watering is increased in July, since this is the period when the berries set. At low humidity, the bush is sprinkled; the procedure will speed up photosynthesis and protect the blueberries from overheating.
Feeding schedule
Denise blue blueberries are fed from the second year of growth. In the spring (before the leaves appear) with a nitrogen-containing agent, and at the time of berry formation - with universal complex fertilizers or a mixture of potassium sulfate (35 g), ammonium sulfate (85 g) and superphosphate (105 g). Fertilizers are applied under the bush, 1 tbsp. l. After two years, the amount is doubled, the maximum dosage is 8 tbsp. l. for mature blueberries.
A mandatory procedure in agricultural technology is soil acidification. In a neutral or slightly acidic environment, mushrooms cannot exist; the death of one participant in the symbiosis affects the viability of the other. If blueberry leaves turn white with a yellow or pink tint, this is the first sign that the soil acidity is low. If the acidity level is unsatisfactory, it is increased by adding 1 m2 one of the means:
- citric acid or oxalic acid – 5 g/10 l;
- apple cider vinegar – 100 g/10 l;
- colloidal sulfur – 1 ml/1 l;
- electrolyte – 30 ml/10 l;
Blueberries react negatively to organic fertilizers; they are not used when growing the crop.
Trimming
Pruning of the Denis Blue variety begins at the age of three. Shoots are shortened by 1/3 of their length in spring. The procedure is continued until the age of fruiting. After 5 years, blueberries are pruned in the fall, twisted branches are removed, and the bush is thinned out. In spring, frozen stems and dry areas are cut off.
Preparing for winter
A frost-resistant plant after five years of growing season does not require crown cover. If the shoots are damaged by frost, blueberries quickly form replacements without loss of yield. In autumn, the bush is watered with a large volume of water and mulched with a layer of peat, wood chips or pine needles. In addition to mulch, young seedlings require crown cover. The branches are pulled into a bundle and fixed. Arcs are placed near the blueberries and covering material is pulled on.
Pests and diseases
For preventive purposes, along with sanitary pruning, blueberries of the Denis Blue variety are treated with fungicides. When a fungal infection occurs, use Fitosporin and water it with a solution of Fundazol. Parasitic on the bush: leaf roller, flower beetle and beetle. They get rid of pests with Iskra, Inta-Virom, and Fundazol.
Conclusion
Blueberry Denis Blue is a garden variety with high yield, frost resistance and standard agricultural technology. The breeding crop was created specifically for cultivation in cold climates. The shrub has a decorative appearance and edible berries, so the crop is grown as an element of landscape design and for harvesting.
