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Jim Shroyer Kansas State

In central Kansas,many fields of wheat were covered in a thick coating of ice on April 11. Byitself, a coating of ice on the surface of leaves and stems will usually notcause direct damage unless the wheat is tall enough that the weight of the icebreaks the wheat over and causes lodging. Ice can also cause leaves to becomewater-soaked and mushy, but this will not affect new leaves.

Ice on the surface of leaves and stems doesn't necessarilymean there will be ice inside the stems. Those are two separate issues. Ifthere is ice inside the stems, that may or may not injure the developing heads.You might think ice inside the stems would always cause damage, but anyone whohas seen a lot of spring freeze events knows that wheat's response can beunpredictable.


There have been times when there was ice inside the stems,and it simply melted and the wheat had normal head development afterward. Itmay depend on how cold the temperatures were when the ice formed. Other times,ice will kill the heads or split open the stems, which usually results insevere injury. Oddly, even split stems do not always mean the end of thetiller. In 1997, there were a lot of split stems that surprised everyone byhealing up on their own, due to the wet mild conditions in the weeks followingthe freeze.


Where stems and/or growing points were killed by the freeze,start looking for new tiller growth coming from the crown area. In fact, lookfor new tiller growth even if you think the stems look okay. Sometimes tillerscan be killed but will not show any symptoms for quite a while. In those cases,the first sign that the tillers are dead is the sudden growth of new tillers atthe base of the plant.


There are many possible scenarios after a freeze, and thingsdo not always go according to "the book." So just keep watching your fieldsclosely over the next 7 to 10 days for the following:


* The color ofthe developing head or growing point. As long as heads are light green andturgid, the head in that tiller is fine. If the head is whitish and flaccid, ithas died.

* The color ofnewly emerging leaves. If they are nice and green, that probably indicates thetiller is alive. If newly emerging leaves are yellow, that probably indicatesthe tiller is dead. The color of existing leaves is not terribly important,except for the flag leaf. Existing leaves will almost always turn bluish-blackafter a hard freeze, and give off a silage odor. Those leaves are burned backand dead, but that in itself is not a problem as long as newly emerging leavesare green.

* The integrityof the stem. If there are lesions or crimps anywhere on the stems, that usuallymeans the wheat will lodge at some point during the season. If the stems lookundamaged, that's a good sign.