The optimum period to plant wheat in the northern mountain and Laurel Highlands regions is upon us (Sept 20 – Oct 3). The optimum period for the hill and valley and the western lake plain regions is September 25-Oct 8. In the area southeast of Blue Mountain the optimum time is October 1 to 15. Planting wheat too early increases the risk of powdery mildew and barley yellow dwarf virus infections. We don’t think about the Hessian fly very much but you do avoid that insect by planting after those dates as well as reducing winter annual weed pressure. In Oklahoma, research indicates that test weight is lower if planted earlier than the optimum date.
Not much wheat is planted back-to-back, but sometimes it is, especially in fields where it got too late to double crop soybeans or in anticipation of a late corn and/or soybean harvest. This invites diseases such as Staganospora, take-all, and powdery mildew, particularly when old straw and chaff remain on the surface. Any volunteer wheat in the field should be eliminated at least two weeks before planting.
Most wheat is planted following corn and soybeans. The “red zone” to avoid is wheat planted no-till in cornfields with a lot of stalks on the surface. There is more potential for head scab next year than if it were soybean ground or even corn ground with more of the stalks tilled in or under. Yields following soybeans tend to be higher than after corn, even in years when head scab isn’t a problem.
Fields testing low in phosphorus are not as scarce as some people think. Make sure that you fertilize fields accordingly if any of yours are in that category. pH is more critical for barley than wheat but don’t take that as an excuse to let it drop down too low.
The recommended planting rate is 1.5 to 1.7 million seeds per acre with the lower end in longer season areas and the higher end in shorter season areas. There is a table in the Agronomy Guide (Table 1.7-3) showing the number of seeds per foot of row needed for various plant populations and row widths. Adjust for seed size. For example, a seeding rate for 1.4M would require 100 lbs/ac of seed with 14,000 seeds per pound. But it would take 127 lbs. of seed to achieve the same number if a seed lot contained 11,000 seeds per pound and 82 lbs. if there were 17,000 per pound. Increase seeding rate to compensate for factors such as cloddy soil or no-till/heavy residue.
Uniform depth of planting (1-1.25”) resulting in even emergence is very important.
Figure 1. Which field would you rather call yours?
Considerations for late planting will be addressed in Part 2 in the next edition of the Field Crop News. Eleventh Hour Reminders for Wheat Planting - Part 2