Right now, in midsummer, the grain crops are at full maturity, and at the same time this is the moment when farmers begin planning the autumn sowing. Given that summer weather is becoming ever harder to forecast, and that rain or even hail with strong winds can give way to heat in a matter of days, the choice of suitable seed material is becoming an increasingly pressing question. Data from the Central Statistical Bureau show that last year the total winter cereal harvest increased by 321.4 thousand tonnes, or 15.3%, compared with 2023, reaching 2.4 million tonnes. The average yield of winter cereals rose from 41.3 centners per hectare in 2023 to 47.5 centners in 2024. If that growth in total harvest is to continue this year as well, the sowing period chosen and the crop's ability to overwinter are decisive, as is suitable weather over the summer.
Latvian summers can catch farmers out with prolonged rain, high rainfall totals, hail, strong winds and even frosts, followed by heat. This can harm crops and lead to heavy yield losses. Many will remember August 2023 all too well, when large hailstones smashed not only farmland but buildings as well. Such summers are often followed by a warm, drawn-out autumn and a sudden bare frost, which is one of the greatest trials a winter crop can face. It poses a serious risk to the survival of the crop, because there is no snow cover on the field to shield the plants from the sharp cold. As a result the roots are damaged and the parts of the plant above ground are frost-burnt too. Much of Vidzeme and Latgale suffered this kind of frost damage last January, when a large share of the winter oilseed rape crop was lost and winter barley and wheat crops were damaged as well. Does the variety matter? When heavy rain and temperatures of +10 °C are followed by frosts of between -13 °C and -21 °C and strong winds, plants have very little chance of surviving overall, though of course some varieties are hardier than others, and every farmer has to assess the situation in their own region and choose the ones best suited to it.
When the weather sets the rules
Although every variety has a recommended sowing period, it is the weather that really points to the best time to sow winter crops. If summer-like air temperatures and humidity persist into early autumn, when the new crop is due to be sown, it may well be worth waiting. In such conditions the growing season continues, and the plants may become overgrown, start to tiller and move on to a stage of development that in normal weather would only be reached once spring returned. Sowing too early in the autumn can leave a farm having to apply extra growth regulators and fungicides, because growth will need to be checked and the warm weather may bring on the first symptoms of disease. These plants will also "breathe" more over the winter, which, when they are lying under a thick layer of snow, can lead to the crop drying out and to snow mould developing.
Yields suffer both from a lack of snow cover and from persistent snow cover without frozen ground, because the moisture and warmth encourage so-called snow mould. This weakens the leaves and promotes the growth of snow mould on their surfaces, so that the leaves die off beneath the snow – which harms both the potential yield and the money already invested. And, given the need to slow growth and reduce disease symptoms, growth regulators and fungicides may have to be used in the autumn. It has to be stressed, though, that planning the sowing is a double-edged sword: sow too late, and the plants may not reach the necessary stage of development in time and so fail to overwinter, reducing the yield potential overall. It is therefore advisable to keep a regular eye on how the weather is changing in your particular region of Latvia. I would also recommend paying closer attention to the views and insights of specialists in the field – listen to them and put their experience to work for you. Several seed suppliers run independent trials, sowing crops at different sowing dates and analysing the resulting data over a number of years.
Will my crop overwinter?
This question comes up every autumn as the sowing season approaches, but no company supplying seed material to the Baltic market will include in its range varieties that risk failing to overwinter in our climate. Unpredictable, risky weather is quite another matter – weather that is not typical of winters in our region but is becoming the norm: frost with wind and no snow, long spells of mild, wet weather alternating with a week of frost and then warmth again. The broad seed market on offer makes it possible to find both winter oilseed rape and cereal varieties suited to your own farm and climatic conditions. Visiting farms and talking to farmers day in, day out, we have repeatedly seen that it is precisely the choice of certified seed material that makes the difference if you want to stop worrying about whether the crop will overwinter and develop evenly. One of the guarantees offered by a certified winter variety is winter hardiness – during the breeding process various winter conditions are deliberately created and simulated, so that it is clear well in advance whether the variety will suit Baltic conditions. We test how varieties overwinter, for example, by clearing the layer of snow off the crop.
Matching the variety to how the farm operates
Choosing a variety that suits the way the farm operates matters just as much. Extensive farms are best advised to favour varieties that are easier to manage and more resistant to the weather while still delivering a high yield potential under those growing conditions – for example the winter wheat varieties “Balitus” and “Delawar”. Farmers who practise intensive management, on the other hand, I would encourage to choose more demanding, higher-yielding winter wheat varieties, bearing in mind the intensity of mineral fertiliser and plant protection product use – for example the winter wheat varieties “Etana”, “LG Nida” and “Asory”. “Dotnuva ANE”, meanwhile, is a blend of three winter wheat varieties that can deliver a good yield potential both in changeable weather and where the soil structure is uneven.
Recent years have brought bare frosts, overly long and mild autumns, and winters of changeable weather – these are the challenges a farmer has to face when growing winter crops. That is why it is important not only to follow the weather closely, but also to pick a suitable winter variety – the one best suited to your own farm and region, which will guarantee both successful overwintering and a stable yield potential. Although a good many farms have grown used to gambling with their finances and their yield potential by choosing to sow uncertified seed material, I would urge farmers to insure at least part of the farm against those risks and buy certified seed.