'Agrotechnical activities in perennial plantations in June'

In June, the atmosphere over the Northern Hemisphere will gradually transition to a typical summer regime. The polar vortex is already significantly weakened and practically disintegrated, which means its influence on the weather in Europe will be considerably less compared to the spring months. For Bulgaria, this means predominantly warm and often hot weather, but with the typical afternoon thunderstorms for the season.

A combination of hotter air from the south and cooler oceanic wave disturbances from the northwest will cause periods of instability, thunderstorms, and brief cooling spells, especially in the western and mountainous regions of Bulgaria.

Overall, the month is expected to be warmer than the climatic norm, with a feeling of early summer from the very first days, and by the end of the month, the country may come under the influence of the first serious heatwave of the year.

Temperatures will gradually increase. Morning values will be between 11 °C and 16 °C, and maximums will reach 25 °C – 30 °C. In the Danube Plain and the Upper Thracian Lowland, the first more significant summer heatwaves with temperatures around 31 °C – 32 °C are not excluded.

Around the middle of the period, a cold atmospheric front may pass through, bringing short-lived but intense rainfall and thunderstorms. There is also a possibility of hail in some places, typical for the beginning of the summer season.

During the second ten-day period, the atmosphere will remain dynamic. Frequent afternoon developments of cumulonimbus clouds are expected, especially in Western and Central Bulgaria. The weather will be typical of June – warm mornings, hot afternoons, and local storms at the end of the day. Precipitation will not be widespread, but in some places it can be significant in amount over a short period.

Minimum temperatures will be between 13 °C and 18 °C, and daytime temperatures – between 27 °C and 33 °C. In some areas of Southern Bulgaria, temperatures may approach 35 °C, especially during prolonged southerly advection. Along the Black Sea coast, the weather will be more stable, with more sunshine and a lower risk of precipitation.

The end of the month will bring a more persistent summer character to the weather. A more stable anticyclonic regime will establish over Southern Europe and the Balkans, which will limit precipitation and raise temperatures. Temperatures will remain above the norm for the period. Minimums will be between 15 °C and 20 °C, and maximums – between 30 °C and 35 °C. In the warmest areas of the country, values up to 36 °C – 37 °C are not excluded. This will likely be the period when we experience the first more prolonged summer heatwave of the season.

In fruit nurseries

Seedling beds are fertilized with 6-8 kg of ammonium nitrate or the same amount of another nitrogen fertilizer per decare and are hoed. Irrigate if necessary.

Mother plantations are fertilized with 10-15 kg of ammonium nitrate or the same amount of another nitrogen fertilizer per decare and are earthed up. If necessary, they are irrigated before earthing up.

In nurseries, disbudding is carried out to facilitate the normal growth of the grafted plants. Rootstocks and nurseries are prepared for budding.

In fruit plantations

Monitor to ensure that the ties do not cut into the branches of top-grafted fruit trees and wild forms, loosening them promptly if necessary. Competing shoots growing from the rootstock must be removed promptly.

Regular hoeing is carried out on newly planted trees. Water if necessary. After the second ten-day period, young fruit plantations are fertilized with 15-20 kg of ammonium nitrate per decare or the same amount of another nitrogen fertilizer, and shallow tillage is performed.

When forming a palmette, the scaffold branches are bent down when they reach a total length of 2 – 2.5 m for the first tier, 1.5-2 m for the second, and 1 m for the third. For weakly growing trees, they are placed at an angle of 45-50°, and for vigorously growing trees – at 45-45° relative to the horizontal. When a tier has scaffold branches of different lengths, only the strong one is bent, while the weak one is left to grow and is bent additionally later.

Mechanical fruit thinning continues for peaches.

On areas with assured irrigation, sowing of green manure crops is carried out.

The mass harvesting of sweet and sour cherries begins.

In strawberry plantations

The last strawberry seedlings stored in a refrigerator are planted.

Weeding care continues for young and newly planted plantations. Irrigate if necessary.

Harvesting continues. Do not pick during the hot hours of the day or when dew is present. For fresh consumption, they are picked together with the fruit calyx.

In warmer locations, after picking the last fruits, the straw is collected immediately and removed. The plantations are fertilized with 8-10 kg of ammonium nitrate or the same amount of another nitrogen fertilizer per decare, and the first post-harvest cultivation is carried out. If irrigation is necessary, it is done before fertilization.

In raspberry plantations

Regular tillage is carried out. Water if necessary, and in fruiting plantations, the rows continue to be cleaned of very weak and excess suckers. The wire support structure is kept sturdy.

In some areas, around mid-June, the harvesting of fruits from early varieties begins. When ripening begins, bee colonies are moved to other plantations, but at a distance of no less than 5 km.

In blackcurrant plantations

The soil in rooting beds is cultivated 2-3 times depending on irrigation, rainfall, and weed presence. Regular cultivations are carried out on both young and fruiting plantations.

Around the middle of the month, fruit harvesting begins in some warmer locations.

In plantations with other crops

Grafting of lemon rootstocks with a growing bud continues.

Care for the rooting of open-air cuttings of pomegranate, fig, and sea buckthorn continues, with the nursery being regularly hoed and watered. Necessary weed control treatments are carried out.

Towards the end of the month, ungrafted rootstocks from last year are budded with a growing bud using buds from persimmon.

Tying of actinidia vines to support stakes continues. Fertilization is carried out with the last 1/3 of the annual nitrogen rate determined for actinidia. Lateral shoots on the main stem of the actinidia are cleaned to stimulate its development and overall shaping. It is formed into a T-shape.

In vineyards

Soil cultivation is carried out where it is not already grassed down, and weed control treatments are applied. The aim of the cultivations is to destroy weeds and break the soil crust. Cultivate shallowly to a depth of 8–10 cm. The number of cultivations depends on weed infestation and rainfall. They are carried out mechanically with cultivators and rotary hoes.

During flowering, such activities should not be carried out: soil cultivation, irrigation, etc., which lead to an increase in atmospheric humidity and a decrease in temperature.

For the control of perennial weeds such as couch grass, bindweed, and wild oats, herbicides with the active substance glyphosate are used, such as Gligol 36 SL or Fast 36 SL, at a concentration of 500/1000 ml/decare.

Couch grass stems are sprayed when they reach a length of 20–30 cm. Gradually, over 15–25 days, they die. Bindweed is sprayed when the stems reach a length of 40–60 cm. Within 7–10 days, they die completely. Field bindweed is sprayed during its flowering period.

Green pruning operations are carried out in young vineyards and in fruiting vineyards.

Pinch out those shoots on which this practice was not carried out in May. On the remaining ones, girdling is carried out, preserving only the shoot tip above the girdle, which must be trained and tied to the supporting wire. Also carried out are a second disbudding of the trunks, threading and tying of shoots in the plantations, lowering for low and medium trunk training, and carefully loosening the ties on green-grafted shoots.

In fruiting vineyards, threading and tying of shoots in the plantations, and lowering for low and medium trunk training are carried out.

Fruiting vines are girdled. The operation consists of removing a ring of bark from the fruit cane, the green shoot, or the vine arm, 2–5 mm wide. Girdling is performed with a special girdling tool. Several important conditions must be observed: it should be carried out 12–15 days after flowering when the berries are about the size of a pea; for vines pruned according to the Guyot training system, girdle after the bend on the horizontal part of the fruit cane. For trunk-trained vines, the ring should be made at the base of the fruit cane. The same vines are girdled every 3–4 years.

Clusters, bunches, and berries are thinned.

When the fruit set percentage is very high, up to 40% of the total number of berries are removed. Mainly unfertilized, small, and deformed berries are removed. This operation is carried out during the cool hours of the day, very carefully, without excessive handling and without rubbing off the bloom on the grape berries.

Shoots in mother blocks are girdled and tied.

In the rooting vine beds, the soil crust is loosened, dew roots are cleaned, and the vines are fertilized.

Cleaning of dew roots is carried out when the first tendrils appear on the shoots. The amounts of farmyard manure and mineral fertilizers are usually, respectively: 1000–1500 kg farmyard manure, 3–4 kg ammonium nitrate, 5–10 kg superphosphate, and 3–6 kg potassium salt or another source of potassium, per decare.