The recommendation is “No”. Does that stop producers from seeding winter wheat into spring wheat stubble? The answer again is “No”.
If rotation limitations have you considering seeding winter wheat into spring wheat stubble, here are some management tips and key things to keep in mind.
- If seeding into wheat stubble, diseases can become a big issue. Diseases such as tan spot and septoria survives on wheat stubble and straw. Both can be severe and begins earlier where winter wheat has been planted into wheat stubble. Fungicides can be used to help control these diseases so make sure to pencil in a fungicide application early in the season. Even more important though here in Manitoba is fusarium head blight (FHB). Like tan spot and septoria, FHB overwinters on cereal stubble so a break of at least one year – preferably two years – is advised between cereal crops. Most winter wheat varieties are either susceptible or moderately susceptible to FHB. However, there have been advances made and there are varieties coming to the market place with improved resistance to FHB, including Emerson (Resistant or R rating) and AAC Gateway (Intermediate or I rating). Plus there is CDC Buteo which is rated as moderately resistance or MR.
- Seed into weed free conditions to manage another disease – Wheat Streak Mosiac. This recommendation actually applies to any type of stubble but is more critical when seeding winter wheat into spring wheat stubble. Eliminate any green cereal growth prior to seeding in order to reduce the ‘green bridge’ that can transmit the wheat curl mite and the wheat streak mosaic virus it carries. At least 10 days between the dry-down of spring cereal crops and the emergence of winter wheat is necessary to prevent problems with the disease, as the wheat curl mite needs a live cereal plant for a host at all times.
- Make sure straw has been properly managed during the spring wheat harvest to reduce interference with seeding and stand establishment. Light harrowing can help spread straw and chaff around. Cereal stubble will provide lots of stems to catch snow and reduce the risk of winter injury; however, you must be careful in managing straw and chaff as the stubble needs to remain standing to be of benefit.
- Volunteer spring wheat in the winter wheat crop next year can cause problems. If any spring wheat volunteers produce grain, this may increase the possibility of downgrading of the winter wheat crop due to mixing of wheat classes. Result can be marketing problems and price discounts.
So, if seeding winter wheat into spring wheat stubble is the only option available, manage your yield and quality expectations.
Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture