Phytosanitary status of agricultural crops as of 09.01 Vineyards

During the first days of August, the agro-meteorological conditions in Western Bulgaria remained unstable. This further hindered the wheat harvest and worsened the grain quality. By the end of the month, the wheat harvest had still not concluded in the higher areas of the Kyustendil, Pernik, and Sofia provinces. In mid-August, the atmosphere stabilized, temperatures rose, and in different parts of the country the maximums reached between 33-38°C.

In the second half of August, part of the spring crops completed their development. The sunflower harvest and the sowing of rapeseed began. In Southern Bulgaria, in areas with less rainfall during the season, the harvest of early hybrid corn also started.

GRAPEVINE

Phenophase: "veraison" - "full maturity"
During August, leaf removal (leaf thinning) was performed in many regions of the country for better sun exposure of the grapes and ventilation of the clusters. Regular sprayings were carried out for disease and pest control, with the intervals between them determined by the mode of action and the pre-harvest interval of the fungicide used, as the harvest of early dessert grape varieties began at the end of August: Perla, Tsaritsa, Super Early Bolgar, Cardinal.

European Grapevine Moth (Lobesia botrana)
During August, the development of the pest's third generation took place. A mass flight was recorded in the first ten days of the month, and in the period August 11-20, mass hatching and damaging activity of the third-generation caterpillars occurred. Density above the economic injury threshold was recorded in the regions of Burgas, Plovdiv, Pazardzhik, Silistra, and Haskovo. In these regions, 145.10 thousand decares were treated 1 to 2 times against the third generation. The high temperatures and relatively low atmospheric humidity in August provoked mass damaging activity of the Yellow Grapevine Mite (Colomerus vitis). In the provinces: Blagoevgrad, Burgas, Vidin, Pazardzhik, and Yambol, the recorded density was around the Economic Injury Threshold. 58.20 thousand decares were treated 1 to 5 times.

Grapevine Scale (Parthenolecanium corni)
Infestation by the pest was recorded in the provinces: Burgas, Vidin, Pazardzhik, Plovdiv, Sliven, Haskovo, and Yambol. 32.20 thousand decares were treated 1 to 2 times.

Downy Mildew (Plasmopara viticola)
The high temperatures in August, the relatively low atmospheric humidity, and the thinning of the grape clusters limited the development of the disease, except in places with local rainfall. The infestation is widespread and affects the leaves, young shoots, and grape clusters. In the main viticultural regions, 8 to 12 incubation periods were registered. In most regions, the recorded percentage of infestation on the leaf surface ranged from 5 to 75% (1st - 5th degree of infestation). On the grape clusters, the infestation ranged from 5-50% of affected berries (1st – 4th degree of infestation), with weaker infestation in the Veliko Tarnovo and Silistra provinces, and the strongest infestation in the regions of Blagoevgrad, Burgas, Kyustendil, and Razgrad. 6 to 8 treatments were performed on 599.32 thousand decares.

Powdery Mildew (Uncinula necator / Erysiphe necator)
Damage from the disease on leaves and grape clusters was recorded throughout the country. The degree of infestation for different regions varies widely (from weak to strong), with determining factors being both the varietal characteristics of the vines and the location of the vineyards. A weak degree of infestation was recorded in the regions of Veliko Tarnovo, Silistra, and Targovishte. A moderate degree was recorded in the provinces of Kyustendil, Pleven, and Shumen, and a strong degree in the regions of Blagoevgrad, Burgas, Vidin, Vratsa, Dobrich, Kardzhali, Pazardzhik, Razgrad, Ruse, Sliven, and Stara Zagora. Treatments were carried out on 599.32 thousand decares, 5 to 8 times. Monitoring of the pathogen's development continues.

Gray Mold (Botrytis cinerea)
During August, the agro-meteorological conditions and the damage caused by downy and powdery mildew on the vines were a prerequisite for expanding the area and increasing the degree of infestation by the disease in all viticultural regions of the country. To date, in most provinces of the country, a low to moderate risk of infection has been recorded. Data indicates a high risk for the Haskovo province. With the ripening of the grapes, the spread and degree of infestation by the disease are expected to increase and the risk of infection to rise. 1 to 3 treatments were performed on 400.24 thousand decares (combined with other diseases).

The disease excoriosis (Phomopsis viticola) on grapevines is highly damaging and is observed in foci, mainly in old vineyards, in all viticultural regions. In the provinces: Burgas, Varna, Vidin, Dobrich, Kardzhali, Montana, Pleven, Plovdiv, Ruse, and Sliven, a weak to strong degree of infection was recorded. 67.10 thousand decares were treated 1 to 2 times.

Observations on the development of agricultural crops and economically important pests continue!