Will Upcoming Cool Temperatures Hurt Winter Wheat?

The short answer, probably not.

Low temperatures may dip to low 30s/high 20s in northern Ohio over the next few days. However, these temperatures should not harm winter wheat at the Feekes 6 to 7 growth stage. [As a side note, I wrote this exact article last year at this time. Temperatures in Ohio were in the low 30s to upper 20s in northern Ohio, but wheat yield ended up being record-high for many famers due to the long grain fill period. Last year, there was even snow on some fields.]

The magnitude of freeze damage depends on: 1) temperature, 2) duration of temperature, and 3) wheat growth stage. A few years ago, we conducted a freeze chamber experiment to examine the effect of low temperature on winter wheat at several growth stages (Table 1). Keep in mind, actual yield reductions in the field can be quite variable depending on the weather for the remainder of the growing season. At Feekes 6 growth stage, temperatures >20°F caused no damage. However, by Feekes 8 growth stage, temperatures of 25°F to 28°F caused a 10 to 25% reduction in wheat yield. These temperatures were from the crown of the wheat plant, not air temperature.

Table 1. Temperature (15-minute duration) at which wheat yield was reduced by 5%, 10%, 25%, and 50% at Feekes 6, 8, and 10.5.1 growth stages. (Data from Alt, Lindsey, Sulc, & Lindsey, 2020).

Feekes growth stage

5% reduction

10% reduction

25% reduction

50% reduction

 

Temperature (°F)

6

20.1

17.9

14.8

11.9

8

30.7

27.6

24.6

21.9

10.5.1

28.7

27.8

26.3

24.1

 

For more information, see our new ‘Freeze Symptoms and Associated Yield Loss in Soft Red Winter Wheat’ FactSheet: https://ohioline.osu.edu/factsheet/anr-93

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.

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