Agrometeorological forecast for February

The high temperatures during the last week of January disrupted the deep dormancy of autumn-sown crops in a large part of the arable regions of the country.

During the first ten-day period of February, the agrometeorological conditions will be determined by temperatures above the climatic norms. At the beginning of the month, weather that is again warm for the season is forecast, with average daily temperatures significantly exceeding the biological minimum required for the resumption of vegetation processes in winter cereal crops. Under the expected unusually high temperatures, up to 17-22°C, there is a high probability that enforced dormancy will be disrupted in early-flowering fruit species (almond, apricot, peach, cherry).

At the end of the first ten-day period, the agrometeorological conditions will undergo a change. The expected substantial drop in temperatures will impede the vegetation of autumn-sown crops and the premature, undesirable development of fruit trees. 

During most days of the second and third ten-day periods, the forecast temperatures, close to the norms for the period, will restrain the development of overwintering agricultural crops in the greater part of the country. Exceptions are possible for winter cereal crops in the extreme southern and southeastern regions during the last week of the month.

In February, the forecast minimum temperatures, down to minus 10°C, are above the critical levels for winter cereal crops in the third leaf and tillering growth stages. These values, in conditions without snow cover and with a more prolonged persistence, will pose a risk only to the most underdeveloped stands, which are overwintering at an initial leaf formation stage (1-2 leaves).

The forecast precipitation during the month, around and below the norm, will improve soil moisture reserves mainly in the 50 cm soil layer. This precipitation will contribute to overcoming the moisture deficit in winter cereal crops in the upper soil layers, which has led to yellowing of part of the wheat stands in places in the eastern regions of the country (Provadia, Devnya, Shabla, Karnobat). In the deeper soil layers, the soil moisture reserves will remain unsatisfactory for the season. In February, in years without climatic anomalies, the soil moisture reserves in the 100 cm layer have usually reached levels close to field capacity.

During the month, more favourable conditions for carrying out seasonal agrotechnical activities — pruning in vineyards and orchards, winter plant protection spraying in fruit plantations, top-dressing of autumn-sown crops with nitrogen mineral fertilizers, pre-sowing tillage of areas intended for sowing with early spring crops (peas, vetch, oats, spring barley) — will occur on most days of the first and third ten-day periods.

During the month, wheat stands must be inspected for the population density of the common vole (EIL – 1 active colony/da), and for the harmful activity of successfully overwintered larvae of the common wheat leaf weevil (EIL – 5 larvae per m²). When pest density exceeds the economic injury level (EIL), chemical control must be carried out at the first opportunity, when conditions permit.

Source: NIMH