Poor emergence or plant stands are leaving many producers wondering if their winter wheat crop will survive the winter, what type of stands they might expect in the spring, and whether the crop will undergo the necessary processes to produce a head next year.   Unfortunately at this stage there isn’t much that can be done except understand the potential impact to crop production if the crop didn’t emerge or has just emerged.

The stage of crop development in the fall influences not only winter survival and yield potential but also crop competitiveness, maturity and the risk of infection with diseases such as rust and fusarium head blight (see Table 1 below).

Table 1:  Potential impacts of fall growth stages on winter wheat production factors

* Competition factor: 5 = most competitive, 1 = least competitive

As the table illustrates, there may be minimal impact to yield potential of a crop that didn’t emerge in the fall but maturity will likely be delayed.  Crop competitiveness may be decreased so early season nitrogen application to encourage tillering, as well as timely weed control, will be very important.

In regards to vernalization concerns and whether the crop will produce heads next year, the key points to remember are:

• Neither fall seedling growth nor tillering is required for vernalization to occur.  This process can begin in seeds as soon as they absorb water and swell.  Hence, late planted wheat that has not emerged prior to winter should be adequately vernalized.
• Vernalization may also occur under cool spring conditions.

If next spring winter wheat fields whose stands are extremely variable with large patches of dead or weakened plants, replanting may become a more realistic option.  If you are considering reseeding and before destroying any wheat fields, you will need to contact your local MASC insurance agent.  For more information on winter wheat insurance information, please visit MASC’s website at: http://www.masc.mb.ca/masc.nsf/program_winter_wheat.html

There are numerous articles on MAFRI’s site dealing with dry conditions and poor germination, including “What Happens if my Winter Wheat did not Emerge?”, “Spring Germinating Winter Wheat” and “Concerned About Your Winter Wheat Stand?”.  For more information on winter wheat production, please visit MAFRD’s website at: http://www.gov.mb.ca/agriculture/crops/production/winter-wheat.html

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD