In short
There is no single date for sowing winter wheat.
Published guides run from the end of August in a dry district of southern Kazakhstan to early November through mid-December in the east Mediterranean of Turkey. The goal is a stage, not a date: enough tillers before winter dormancy. Planva keeps the planned and actual sowing for each field, so you can see which date you really used and what followed.
Dates from sourced zonal guides
The rows below come from published agroclimatic calculations and field trials. They are examples of how much the window moves between zones, not recommendations for your field. Not every country has a comparable published guide, so treat missing zones as unknown and ask your regional research institute.
| Zone | Window in the source | Basis |
|---|---|---|
| Saudakent, Zhambyl region, Kazakhstan (dry) | 28 August to 7 September | Agroclimatic calculation from 1981 to 2000 data |
| Merke, Zhambyl region, Kazakhstan | 14 to 24 September | Same study, average years |
| Burno-Oktyabrskoe, Zhambyl region, Kazakhstan | 7 to 14 September | Same study, average years |
| East Mediterranean, Turkey | Early November to mid-December | Field trial, 1997 to 1999, seven dates from 9 October |
In the Kazakhstan study, wet and warm years allow sowing after the dates shown: after 24 September at Merke, after 14 September at Burno-Oktyabrskoe and after 7 September at Saudakent. The authors expect plants sown in the windows to enter winter dormancy with three to five tillers and well hardened.
What the date is aiming at
The aim is a plant stage at dormancy, not a calendar day. Three to five tillers would be BBCH code 23 to 25 in the BBCH scale if counted as the monograph counts them. That mapping is ours, and the study may count tillers differently. Sown too early, a crop can run ahead of the season. Sown too late, it can go into winter too small. The date that reaches the target tiller stage moves with temperature and moisture, so it differs between zones and between years.
What a sowing-date trial shows
A trial at Kahramanmaras, Turkey, in 1997 to 1999 sowed three bread wheat cultivars on seven dates, starting on 9 October and about 15 days apart. Sowing date significantly affected grain yield. The first five dates gave statistically similar yields, and the authors put the optimum from early November to mid-December. A Turkish-language abstract of the first season recommends early November to the second week of December, so check the end of that window in the full paper before you rely on it.
A 2014 to 2016 trial in Khorezm, Uzbekistan, compared sowing on 1, 10 and 20 October with three cultivars. Its abstract reports the highest yields at the optimal sowing time but does not say which of the three dates that was.
How to choose a date for your fields
- Start from the regional recommendation. Your research institute or extension service has dates for your zone and your varieties.
- Match the date to the preceding crop and moisture. A field that comes off a crop late, or lacks moisture in the seed layer, may need a different date from the rest.
- Plan the stage, not the day. Decide the tiller stage you want at dormancy and watch autumn temperature.
- Record what you did. Keep the actual sowing date for each field, and the stage the crop reached before winter.
How this works in Planva
- Sowing in agroplans. The Sowing profile holds seed by rate or quantity, planned and actual.
- Season record. Crop rotation holds crop, variety, sowing and harvest dates, yield and total harvest.
- Growth stages. BBCH phenophases are in the reference catalogues.
- What it does not do. Planva records dates and stages. It does not recommend a sowing window.
Next, wheat growth stages explains the codes used above, and wheat yield shows the national levels the crop is judged against.
Sources
- Bultekova L.S., Baisholanov S.S., Agroclimatic conditions of autumn growth and overwintering of winter wheat in Zhambyl region, Hydrometeorology and Ecology, 2005, No. 4
- Dokuyucu T., Akkaya A., Yigitoglu D., Effect of different sowing dates on growing periods, yield and yield components of bread wheat in the east-mediterranean region of Turkey, Journal of Agronomy, 2004
- Gandjaeva L., Effect of sowing date on yield of winter wheat cultivars in Khorezm region, Bulgarian Journal of Agricultural Science, 2019
- Meier U. (ed.), BBCH Monograph, 2nd edition, 2001
Common questions
It depends on zone. The guides we verified run from 28 August to 7 September at a dry site in southern Kazakhstan, to early November through mid-December in the east Mediterranean of Turkey.
The real Planva interface, shown with test data.
