With lack of snow cover and most of the state experiencing single digit temperatures last week, there have been a few questions regarding the condition of winter wheat in Ohio. Right now, most of the wheat in Ohio looks fine. In northwest Ohio and in the Wooster area, most of the wheat was in good condition before winter began and fortunately there have been minimal periods of standing water and ice. However, in western Ohio, there have been some reports of leaf “burn” from cold winds.
Air temperatures are on the rise early this week followed by cooler conditions by the end of the week. Warm-up followed by cold weather can negatively affect yield, especially if wheat was planted late. In the fall, wheat stores some carbohydrates in the crown. Late-planted wheat does not have time to produce and store as much carbohydrate before the weather turns cold. Warm-up/cold cycles tend to use up stored carbohydrates and reduce winter-hardiness.
However, winter wheat is a cold season grass that can tolerate fairly harsh weather conditions. Wheat “hardens” in the fall to acclimate to cold conditions. Cold acclimation is variety-dependent and requires a period of growth when temperatures are between 30° and 60°F followed by slowly declining soil temperatures. After hardening, wheat can tolerate temperatures between 0 and 10°F especially when there is good snow cover. The growing point of wheat is below ground until conditions are warm in the spring, but extremely cold conditions can still cause damage to the plant. However, plants are only killed by low temperatures if the crown (lower stem) is damaged.