Agrometeorological forecast for October

In October, agrometeorological conditions will be dynamic, with temperatures close to the climatic norms and precipitation above the monthly norms.

During the first days of October, higher-than-usual temperatures for the season are forecast, creating conditions for the formation of additional yield from late vegetable crops, as well as for an increase in the sugar content in the fruits of autumn varieties of fruit trees and late wine grape varieties.

After the above-normal temperatures, a short-term cooling and normalization of thermal conditions is forecast during the second half of the first ten-day period.

During the first ten-day period of October, significant precipitation is expected, which will further hinder seasonal agrotechnical activities. Better conditions for carrying out pre-sowing soil tillage and sowing of winter crops are expected during the first half of the second and during most days of the third ten-day period.

The drought and the subsequent significant, in places intensive, precipitation at the end of summer and the beginning of autumn were the reason for missing the optimal sowing dates in September for winter rapeseed. A significant part of the planned areas will be sown in October, after the agrotechnical deadlines. Due to these objective reasons, there is a likelihood that the late-sown rapeseed stands will not manage to form a rosette (7–8 leaves) during their autumn vegetation – the phase in which the plants overwinter successfully.

October is the optimal period for sowing winter cereal crops. During the first ten-day period is the agrotechnical deadline for sowing wheat in Northern Bulgaria, from 15 to 25 October – in Southern Bulgaria, and at the end of the month –  in the areas along the Black Sea coast.

During the month, the initial stages of vegetation of the sown winter crops will proceed at moderate rates, given the presence of good moisture reserves in the upper soil layers. At the end of October, in wheat, depending on the sowing dates, the emergence and third leaf stages will be observed. In the earliest sown stands, at the end of September and the beginning of October, the beginning of the tillering stage will also be observed. In rapeseed, leaf formation will predominate.

The forecast thermal conditions in October, close to the norm, are a prerequisite for an increase in the population of the common vole – one of the dangerous pests in winter crops. By the end of the month, winter stands must be inspected for the presence of the pest, and if its density exceeds the economic threshold of harmfulness (2 active colonies per decare), timely plant protection measures are necessary (poisoned baits placed at the entrances of the colonies).

At the end of October, conditions will allow the implementation of certain phytosanitary activities in orchards. Apple and pear orchards affected by scab, after harvest, must be treated with a 5% urea solution to reduce the infection. In stone fruit species, after mass leaf fall, spraying with a 2% Bordeaux mixture is recommended against the causal agents of shot-hole disease, early brown rot and peach leaf curl.

Source: NIMH