Winter Wheat Must be Seeded on Time

It’s the end of August and with harvest of spring crops well underway we head right in to seeding winter wheat. Good stand establishment is critical for winter survival and early spring vigor. Producers need to consider the following factors when sowing this crop.

Winter wheat must be sown into stubble to reduce the risk of winterkill. Standing stubble traps snow, keeping soil temperatures warm enough to allow the crop to overwinter. How you deal with residue from the previous crop will affect seedling establishment and winter survival. The snow-trapping ability of the stubble must be adequate, ie tall enough and uniform across the field to trap a loose, insulating blanket of snow over the winter. Residue must be managed so it doesn’t interfere with seeding operations and needs to be evenly distributed to allow good stand establishment and uniformity of crop development. Care must also be taken to avoid excessive traffic on the field during harvesting as to avoid trampling down stubble. Canola stubble is an ideal choice but you can seed into other crop residue as long as there are enough stems of decent height to trap snow. Producers should be aware of MASC – Insurance coverage on winter wheat in relationship to seeding into “eligible stubble”. Contact your local MASC agent for full details. Water can be a limiting factor in crop production and the trapped snow will melt and become available for crop use in the spring.

Winter wheat must be seeded shallow since deep seeding results in weak, spindly plants, leading to winterkill, poor weed competition, later maturity and lower yield. Soil moisture demand from the previous crop usually creates a dry seedbed, and seeding deeper does not necessarily get the seed into moisture. Soils are cooler in the fall and with less evaporation off the surface light rains can soak into that top inch of soil and be accessed by the seed. As little as 1/3 inch of rain is often enough to successfully establish winter wheat. The crown will develop ¾ to 1 inch below the surface, so seed placement at that depth is ideal. Deep seeding means the plant has to expend extra energy to move that crown up. Seeding rate should be 1.5 to 2.5 bu/acre to achieve a target plant population of 20-30 plants/square foot. Information is available on the MAFRI website to calculate seeding rates by plant population:

(http://www.gov.mb.ca/agriculture/crops/cropproduction/faa03s00.html ).

Winter wheat must be seeded on time, ideally between August 25 and September 5. Crop Insurance deadlines are August 20 to September 15, with reduced coverage to September 20. Seeding too early allows the crown to get too big and then is more susceptible to freezing injury. Seeding too late usually results in poorly established plants with lower winter survival potential. We want plants to have a well-developed crown and about 3 leaves going into the winter. This year’s leaves and roots will die off but the crown survives to initiate new growth early next spring.

Always use starter fertilizer with winter wheat. Phosphorus is important for root growth, winter survival of the crown, and recovery from winter injury. Generally 30-40 lbs P2O5 is sufficient. Do not seed-place nitrogen with winter wheat as the risk of winter injury is increased. Nitrogen can be side-banded or mid-row banded, or applied after seeding in fall or spring. Potash can be applied as KCl, potassium assists with stem strength and chloride helps with disease resistance. Apply sulphur according to soil test recommendations as it aids in production of amino acids, the building blocks of protein. If your winter wheat protein is low despite adequate N fertilization, or if you have high S-using crops in rotation then adding 5-7 lbs S/acre can help.

Employ a proper weed management program in the fall. It is important to control biennial and perennial weeds, either in the previous crop or prior to seeding, as they can very competitive during establishment. To eliminate the risk of Wheat Streak Mosaic Virus, it is imperative that any volunteer spring or winter cereal plants be completely controlled prior to seeding winter wheat. Fall germinating winter annuals such as stinkweed, flixweed and shepherd’s purse can be controlled through the proper use of post-emergent herbicides in late fall. By removing early weed competition, the result will be a well established winter wheat crop which has better ability to survive the winter.

Written by Kim Brown-Livingston, Farm Production Advisor, Carman, & Pam de Rocquigny, Business Development Specialist – Feed Grains, Carman with information from the MAFRI web site and the Winter Wheat Production manual.

 

For further information, contact your GO representative.