Increased likelihood of hailstorms and high infectious pressure from fungal pathogens in agricultural crops in June

During the first ten-day period of June, agrometeorological conditions will be determined by unstable and cool weather for the season. The forecast precipitation during the ten-day period will maintain a high level of soil moisture reserves in the 50 cm and 100 cm soil layers – in most of the field areas above 80–85% of field capacity (FC). The presence of very good soil moisture reserves at the beginning of June will have a beneficial effect on the winter cereal crops, in which grain filling, grain formation and the milk ripeness stage will proceed in the crops in the southern and southeastern regions of the country. During the interphase period grain filling – milk ripeness, damage to wheat is caused by the larvae of the sunn pest, which requires field inspection of the crops and, when the pest density exceeds the economic injury threshold (2 larvae/m2), timely treatment.

After the cool weather at the beginning of the second ten-day period, an increase in temperatures and acceleration of the development rates of agricultural crops is forecast. By mid-June, in most of the field areas, barley will reach the wax ripeness stage.

During most days of the second half of June, the development of agricultural crops will take place at temperatures close to the climatic norms. At the beginning of the third ten-day period, wheat will predominantly be in the ripening stage.

By the end of the month, part of the spring crops will enter reproductive development stages: in sunflower, the beginning of flowering will be observed, and in early maize hybrids – tasseling and flowering of the tassel.

The meteorological conditions in June will maintain an elevated infectious background of fungal pathogens: downy mildews in vegetable crops, late brown rot in later cherry cultivars, scab and powdery mildew in fruit trees. In grapevine, the interphase period from flowering of the inflorescences to fruit set at pea size is critical for downy mildew infection.

During the month, more favourable conditions for conducting plant protection spraying will occur in the first half of the second and during most days of the third ten-day period.

In June, the probability of hailstorms will remain elevated. After a hailstorm, the affected fruit and vegetable crops should be treated at the first opportunity (preferably within 48 hours after the event) with copper-containing fungicides.

Source: NIMH