If your winter wheat plant stands are poor and you do decide to re-seed after a MASC agent has adjusted your field, a couple of management strategies should be noted. Winter wheat is hard to kill. Tillage and/or burn-down herbicides will not likely control all plants, especially if some are suffering injury and slow spring regrowth. Delay applications until the plants have greened-up and are actively growing. In-crop volunteer cereal herbicides may also be required. Producers should also remember to credit any spring applied nitrogen to the following crop.
If considering replanting to a cereal, wheat streak mosaic may carry over from infected winter wheat fields into spring seeded cereals so caution should be excercised. Spring wheat is the most susceptible of the cereal crop types to wheat streak mosiac, followed by barley, then oat. It is recommended that there be 2 weeks with no living green material to try and mitigate the risk of infection to the reseeded crop – if the risk of wheat streak mosiac is considered to be a concern. Also keep in mind that any winter wheat volunteers that produce grain may increase the possibility of downgrading of your reseeded crop.
Canola, flax and soybean are not susceptible to wheat streak mosaic and may be considered as plant back options into a winter-killed stand. Each crop has potential watch-outs which should be considered, specifically if the stubble that the winter wheat was seeded into was canola.
Canola – you are essentially planting canola on canola. This puts the canola crop seeded at higher risk for disease development of sclerotinia and blackleg as the disease incolumn is at high concentrations in the soil and on the crop stubble from the previous canola crop. To assist in managing the disease risks, a fungicide should be considered at the 2-4leaf stage to suppress blackleg and another fungicide used at the 20-50% flowering stage for sclerotinia management. Canola may still be a consideration, especially if the winter wheat crop is already fertilized with nitrogen, as canola nitrogen needs are similar to winter wheat.
Flax – there is the potential for early season phosphorus deficiency due to reduced arbuscular mycorrhizae in the soil that flax is dependent on for early phosphorus uptake. There are also concerns with controlling volunteer winter wheat plants in flax, as flax is a poor competitor. Finally, if fertilizer has already been applied to the winter wheat crop in excess of 80 lbs/ac, the flax crop will be more prone to lodging and delayed maturity.
Soybean – there is concern about volunteer canola in the soybean crop that cannot be controlled (specifically if the canola stubble crop was Roundup Ready). There is the potential for sclerotinia development, but not as high of risk as seeding back to canola. If the winter wheat was fertilized with nitrogen, soybeans will not nodulate and fix their own nitrogen, which could leave them deficient at the end of the season. It will also cause maturity delays.
Another option may be grain corn. As with flax though, there is the potential for early season phosphorus deficiency due to reduce arbuscular mycorrhizae in the soil. Volunteer RR canola control could be a concern in a RR grain corn system. However, if nitrogen applications have been made, nitrogen should be close to the proper range needed.
For long season crops such as soybeans and grain corn, AgriInsurance seeding deadlines are approaching. Please talk with your local MASC agent or visit their website if you have any questions regarding seeding deadlines and insurance coverage in your area: http://www.masc.mb.ca/masc.nsf/crop_seeding_deadlines.html