August – the deficit of soil moisture will be a limiting factor for the development of late agricultural crops

In August, agrometeorological conditions will be determined by temperatures around and above the climatic norms. During the month, the deficit of soil moisture will be a limiting factor for the development of late agricultural crops. As a result of below-normal July precipitation and prolonged hot periods with extremely high maximum temperatures, up to and above 40°C, soil moisture reserves are scarce. At the end of July, in most of the field areas there was no productive moisture in the 50 cm soil layer, and in the 100 cm layer the level of moisture reserves was below 50% of field capacity. In part of the southern regions, moisture was absent throughout the entire one-metre soil layer.

The forecast local precipitation in the second half of the first ten-day period of August will be of no particular economic significance and will not lead to a substantial change in the level of soil moisture reserves. The soil moisture deficit will necessitate an increase in irrigation norms for vegetable crops, autumn varieties of fruit trees and late maize hybrids. By mid-August, depending on their earliness, different phenological stages will be observed in maize: in early hybrids – dough and full maturity, in medium-early hybrids – milk maturity, and in late hybrids – grain filling will be in progress.

The forecast hot and dry weather in the second half of August will accelerate the final stages of development of late spring crops. At the end of the second ten-day period, sunflower in the field areas will generally reach technological maturity, and by the end of the third ten-day period a large part of the medium-late maize hybrids will enter the dough maturity stage.

In August, maximum temperatures in the range of 35-40°C are forecast. These values will have a negative impact on flowering and fertilisation in vegetable crops from late production (cucumbers, green beans, courgettes).

The dry weather during most days of the month will limit the development of a number of fungal diseases, with the exception of powdery mildews in fruit and vegetable crops. In August, the harmful activity of the second generation of fruit worms continues. An increase in mite populations is expected. In vineyards it is necessary to monitor the occurrence and density of caterpillars of the third generation of the European grapevine moth. Where necessary, plant protection treatments should be carried out during the cooler hours of the day, at temperatures below 25°C, using plant protection products with an appropriate pre-harvest interval, in accordance with the ripening period of the crops.

The deepening drought in the second half of the month will hinder the implementation of pre-sowing tillage on the areas designated for sowing with winter oilseed rape. The agrotechnical sowing periods for oilseed rape begin in the third ten-day period of August.

Source: NIMH