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Freeze injury update – worse than we thought

On April 4th I toured southwest Oklahoma and surveyed freeze injury to wheat. In my experience, most freeze events are overhyped; however, this one was the real deal Holyfield.  I traveled a route from Faxon to Chattanooga to Altus to Blair and ended up at Apache. Damage was similar at all sites, with injury ranging from 50 to 80%.

The best looking wheat was the hardest hit. Particularly troubling are some fields in the Altus area that easily had 80 bushel potential prior to the freeze. In most of these fields we are too far past the tillering stage to have yield compensation from secondary tillers. Late-emerging fields that were jointing or smaller escaped the freeze with little injury. Fields that had been heavily grazed and/or under-fertilized also escaped with relatively minor injury.  Conditions improved slightly when I checked wheat in the Chickasha area and injury was more in the 10 – 30% range.

I am frequently asked if the injured wheat head will go ahead and “push through” as the season progresses, and the answer is no. So, if you see heads emerging out of the boot in a few weeks, they are likely not damaged and a head count at this stage will be a reasonable estimate of fertile heads. Since there will not be additional stem elongation in freeze injured wheat, it will not accumulate as much tonnage as in a ‘normal’ year.

I have posted a few pictures below showing freeze injury symptoms. Freeze injury can vary greatly among fields and even within a field. So, it is important to check several sites within a field and split several stems when determining the percent injury. Check early maturing varieties such as Jackpot, Billings, and Everest first, as they are most likely to have injury.


Endurance wheat collected from plots at Chattanooga, OK. The two top heads are freeze damaged and will not recover. Note the shriveled, white appearance of the wheat head. The bottom head was not injured and is healthy green.

A healthy head of Endurance  from Apache, OK.

A healthy head of Endurance from Apache, OK.

Even though this wheat was just past jointing, it was injured by the freeze and the head was lost.

Even though this wheat was just past jointing, it was injured by the freeze and the head was lost.

Freeze injured Billings from the Altus research station

Freeze injured Billings from the Altus research station

A sign of the drought. Wheat seed still easy to find on a sample from near Altus, OK April 4.

A sign of the drought. Wheat seed still easy to find on a sample from near Altus, OK April 4.

First hollow stem update 03/08/2013

We are not progressing towards first hollow stem as quickly as I anticipated, but most varieties are getting close. The drought has likely slowed onset of first hollow stem. Keep in mind that drought stressed wheat might need longer to recover from grazing, so it will likely be better to remove cattle a little early in 2013.


                 cm of hollow stem

Variety           03/06/13

Jagger             .

Endurance       0.46

Deliver             0.43

Pete                 0.4

Ruby Lee         1.3

Garrison           1.44

Duster              0.49

Gallagher        .

Iba                   0.78

Fuller               1.99

Everest           .

Jackpot            1.69

Doans              0.55

Greer               .

CJ                    0.38

Razor               .

Armour             1.7

WB-Cedar        0.82

WB-Redhawk    2.71

T153                2.27

T154                2.44

T158                0.5

OK08328         0.36

*Average of ten hollow stem measurements in wheat sown 09/20/12 at Chickasha, OK


                 cm of hollow stem

Variety            03/05/13

Jagger                 1.1

Endurance          0.2

Deliver                 0.7

Pete                    0.3

OK Bullet            0.5

OK Rising            0.7

Centerfield          0.3

Ruby Lee             2.4

Garrison               1.6

Duster                  .

Gallgher              0.7

Iba                       0.1

Billings                0.4

Fuller                   1.8

Everest                .

Jackpot                1.5

Doans                  1.7

Greer                   0.5

CJ                        0.2

Razor                   2.8

Armour                1.2

WB-Cedar            1.1

WB-Redhawk       0.9

WB-Duece CL+    .

WB-Grainfield      0.7

Winterhawk          1.2

WB-4458             .

T153                   1.7

T154                   2.0

T158                   0.1

LCS Mint             0.1

LCH08-80            0.1

LCH08 – 109        0.3

T173                   0.4

Byrd                     0.1

Brawl CL+            0.1

TAM 113             0.4

OK09915C          0.4

OK09935C          0.4

OK09634             0.5

OK09125             0.4

OK09528             0.2

OK09729             0.4

OK08328             0.1

*Average of ten hollow stem measurements in wheat sown 09/18/12 at Stillwater, OK


Onset of first hollow stem was affected by severe drought stress

First hollow stem update – 03/01/2013

The OSU Small Grains Extension team checked first hollow stem at Chickasha and Stillwater this week. Measurements from both locations are provided in the tables below. Varieties with 1.5 cm or more of hollow stem are considered to be at first hollow stem. Numbers have not changed much at Chickasha due to the cold weather; however, with temperatures climbing into the 60’s next week we should see rapid progression of first hollow stem. Although planted a few days earlier, Stillwater is about a week behind Chickasha in terms of first hollow stem. This is due to severe drought stress at Stillwater. In fact, there were a few times I questioned wether or not the Stillwater plots would survive. In this situation it is important to not only consider first hollow stem but also the amount of green leaf area remaining after grazing. Wheat with less than 60% ground cover at jointing will likely not achieve full grain yield potential, even if cattle were removed prior to first hollow stem.


                     cm of hollow stem

Variety               02/28/13

Jagger                   2.5

Endurance             0.1

Deliver                   0.3

Pete                       0.2

Ruby Lee               1.1

Garrison                 0.8

Duster                    0.5


Iba                         0.4

Fuller                     1.5

Everest                 –

Jackpot                  0.7

Doans                    0.4

Greer                     1.6

CJ                          0.8

Razor                     4.0

Armour                   1.0

WB-Cedar              1.1

WB-Redhawk          1.1

T153                      1.2

T154                      1.0

T158                      0.3

OK08328               0.4

*Average of ten hollow stem measurements in wheat sown 09/20/12 at Chickasha, OK




                     cm of hollow stem

Variety               02/27/13

Jagger                     0.4

Endurance              0.1

Deliver                     0.7

Pete                        0.3

OK Bullet                0.1

OK Rising                0.4

Centerfield              0.3

Ruby Lee                 1.2

Garrison                   0.5

Duster                      0.0

Gallgher                  0.3

Iba                           0.0

Billings                    0.2

Fuller                       0.5

Everest                    2.3

Jackpot                    0.8

Doans                      0.5

Greer                       0.4

CJ                            0.0

Razor                       0.6

Armour                    0.1

WB-Cedar                0.6

WB-Redhawk           0.9

WB-Duece CL+        4.2

WB-Grainfield          0.4

Winterhawk              0.6

WB-4458                 1.6

T153                       0.9

T154                       0.7

T158                       0.1

LCS Mint                 0.1

LCH08-80                0.0

LCH08 – 109            0.2

T173                       0.0

Byrd                         0.2

Brawl CL+                0.2

TAM 113                 0.3

OK09915C              0.1

OK09935C              0.1

OK09634                 0.0

OK09125                 0.1

OK09528                 0.0

OK09729                 0.2

OK08328                 0.1

*Average of ten hollow stem measurements in wheat sown 09/18/12 at Stillwater, OK


Onset of first hollow stem was affected by severe drought stress

How dry is it?

It was too nice of a day to stay in the office yesterday, so I checked on our wheat variety plots. I started at McLoud, moved west to Kingfisher, and ended up at Marshall. As indicated by the pictures and captions below, neither the wheat nor my mood improved as I traveled west. I am sure if I had traveled farther west, this would have gotten worse. The bottom line is that we are in desperate need of moisture in Oklahoma. Early-sown wheat is backpedaling quickly and cannot hold on too much longer. Much of the later sown wheat has yet to emerge. We are certainly not on our way to a record year, but everything could still turn out okay……..if it rains.