The Drought Monitor remains essentially unchanged from last week except that dry conditions are creeping eastward a bit, however, the rest of Kansas is in good shape with moisture. Wheat is still being top-dressed with nitrogen and herbicides as applicators are playing catchup as they are now trying to prepare for corn planting which should start shortly, weather permitting. There are also some wheat fields experiencing cutworm infestations and that is also being addressed. We will address the freezing temperatures shortly. The six to ten day outlook (April 8 to 12) has normal to above normal precipitation and normal to above normal temperatures for the state. Looking out eight to 14 days (April 10 to 16) indicates above normal precipitation and below normal temperatures. The 30 day outlook (April) is for equal chances of normal to above normal temperatures and equal chances of normal to above normal precipitation with the 90 day outlook predicting above normal temperatures and equal chances of below or above normal precipitation. Briefly, let’s discuss the below freezing temperatures this past Friday.
The growth stage of wheat as of this past week is all over the map. Overall, wheat has tillered well and actively growing. Some fields are jointing, i.e. first hollow stem, which means the growing point on those jointed tillers is not above the soil surface. Friday morning, as this is being written, we are below freezing and are staying there for several hours. Did this damage the developing wheat heads? Maybe. For wheat tillers that haven’t yet jointed, likely not as being below the soil surface should protect them, especially those fields with good vegetative cover. In some fields which have jointed, damage is possible, especially on primary tillers. Several things here matter. How far above the soil surface the developing head is. If it is close to the soil surface, the warmer soil can help protect it. Second, the temperatures we see are recorded and meteorological screen height which is 1.5 meters (five feet) and temperatures at the surface are warmer. Lastly, while the primary and some of the secondary tillers may have jointed and been damaged, these more developed fields have other tillers that haven’t jointed. Normally not all tillers will produce a head and kernels. However, if some of the more advanced tillers are damaged they can go ahead and produce heads. One factor in the crops favor is most soils have adequate moisture and this helps the soil maintain heat better. And wheat plants not experiencing drought stress are better able to withstand colder temperatures. Another factor somewhat helpful is air temperatures are predicted to gradually warm up over several days instead of immediately returning to the seventies.
One last quick note on how to determine damage. If a producer is concerned, and most know how to do this, wait several days and allow temperatures to warm back up. Select jointed tillers, remove them and carefully split them in two to reveal the developing head. If the head is a nice healthy green color and not looking “wilted” it should be fine. However, if it looks water-soaked, you can’t miss this once you see it, it has been damaged. One caveat, the head may look fine but the tiller may have sustained damage to the vascular system. The tiller will look fine and develop normally until experiencing moisture stress due to heat, wind, lack of soil moisture or a combination of those factors.
Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207.