Avoid planting wheat prior to the fly-safe date because of the possibility of early establishment of foliar fungal diseases and severe damage by barley yellow dwarf virus and Hessian fly (Figure 6-1). The best time for seeding is a 10-day period starting the day after the fly-safe date. Long-term average yields are highest from seedings made during that time (Figure 6-2). Seeding during that time usually produces ample growth for winter survival, and reduces the likelihood of fall disease establishment and at- tack by potentially damaging insects. Occasionally, when freezing weather is delayed until late November or early December, wheat seeded more than three weeks after the fly-safe date is equal in yield to that seeded during normal planting time. Because of reduced fall growth, late seeded wheat is less winter hardy and more susceptible to spring heaving.
Figure 6-1. Hessian fly-safe dates for planting wheat for Ohio counties.
Figure 6-2. Effect of planting date on wheat.