През септември – добро ниво на влагозапасите и подходящи условия за провеждане на сезонни полски работи

During the first half of the first ten-day period of September, agrometeorological conditions will remain unstable, with frequent precipitation that will maintain good moisture reserves in the upper soil layers in most of the field areas. The widespread precipitation that fell during the third ten-day period of August, exceeding in many parts of the country 30-40 l/m² (Lom - 44 l/m², Oryahovo - 54 l/m², Knezha - 53 l/m², Plovdiv - 36 l/m², Kardzhali - 72 l/m², Chirpan - 67 l/m², Ahtopol - 60 l/m²), increased soil moisture reserves in the 50 cm layer. This precipitation was late for part of the spring crops grown under rainfed conditions, which, as a result of the soil moisture deficit, completed their vegetation prematurely.

During the first and most of the days of the second ten-day period of September, the development of late agricultural crops that have overcome the adverse effects of the summer drought will proceed at an accelerated pace, at temperatures around and above the climatic norms. At the beginning of September, the development of the medium-late maize hybrids will be completed. In the late hybrids, the milk maturity stage will be observed, and in the middle of the month – the wax maturity stage.

At the beginning of the second ten-day period, precipitation is again forecast and an increased risk is expected for the development of pathogens causing rotting of the ripe and ripening fruit and grape yield - grey mould on grapes, late brown rot on the fruits of autumn-winter varieties of fruit trees.

During the month, periods with relatively dry weather and more favourable conditions for carrying out seasonal field work: harvesting of sunflower and earlier maize hybrids, performing deep ploughing and pre-sowing tillage of the areas designated for sowing with winter crops, and the sowing of winter oilseed rape, are expected during the second half of the first and most of the days of the second ten-day period. Until the end of the second ten-day period of September, the agrotechnically optimal time limits for sowing oilseed rape will apply.

During the third ten-day period of September, stabilization of the weather, a substantial decrease in temperatures, and the transitional changes in agrometeorological conditions typical for the end of summer and the beginning of autumn are forecast. The expected precipitation during this period will provide moisture for normal emergence of winter oilseed rape stands sown within the agrotechnical time limits.

In the emergence stage, damage to oilseed rape is caused by the cabbage stem flea beetle (adult individuals) and the rape leaf sawfly (false caterpillars), which requires that the emerged stands be monitored for the presence of these pests and, when their density exceeds the economic injury level (EIL for the cabbage stem flea beetle - 2 beetles per m²; EIL for the rape sawfly - 2-3 false caterpillars per m²), timely treatment should be carried out.

No frosts are forecast in the field areas by the end of September, which will provide conditions for the formation of additional production from vegetable crops of the late field production.

Source NIMH