STRAIGHT FROM THE HORSE'S MOUTH

Duane A. Lienemann, UNL Extension Educator, Webster County May 8, 2010 Edition As I sit down to write this column it is the beginning of Mother’s Day Weekend, which for many schools in the area also marks high school graduation. I would be remiss if I didn’t take this opportunity to wish all of the moms out there a very happy Mother’s Day and to remind everybody how important that our mothers are in our lives and our society. To our area graduates – Congratulations and good luck as you start your first steps towards your chosen career paths. I think back to all of the graduations that I have attended and can remember all kinds of weather that we have experienced including the beautiful day following a morning freeze on May 8. That is the sedge way into this week’s column – the weather. Frost on the Pumpkin? Well, that term is mostly used for the first frost in fall but you heard those words in coffee shops Saturday morning after we woke up from a chilly night, to frost on the windshields and even ice in the dog’s water bowl. Did anyone forget to dump out their rain gauge? I have already fielded quite a few questions about the effect on newly emerged corn and beans and particularly on alfalfa. The quick answer is – “I don’t think it got cold enough, long enough to do much damage”. That being said however, there could be some tissue damage to cold sensitive crops like newly emerged soybeans and even alfalfa that was located in low land areas (especially in early bloom), but I doubt enough to do major damage, and corn should have avoided any damage, since the growing point should still be below the surface. I am actually more worried about the effect that “crusting” may have on the corn and beans that are trying to emerge. How about the wheat? Wheat in South Central Nebraska is in several stages of development depending upon where it is located and how early it was planted. Just like every other year, the wheat in the southern third of the southern tier of counties along the Kansas border is further along with flag leaf showing and even some wheat in the boot stage while further north we are seeing flag leaves, but are a bit behind with boot. I know that we lost some wheat in southeast Webster County and southwest Nuckolls County to hail and wind. I feel bad about that happening, but I guess it shows us that we don’t have any control on that phase of our production cycle. Since the wheat does look pretty good this year, people are worried that the frost could affect their wheat. I always refer to an old rule of thumb for wheat. – It has to be 24 degrees for 2 hours for wheat in the jointing stage to be lethal and 28 degrees for 2 hours if it is in the boot stage. Once again, I don’t believe that we experienced this in our part of the country. Producers should know by the time they read this in the paper! Yellow wheat: I believe that the higher degree of moisture, cool soil and air, and lack of optimum growing conditions have caused an environmental problem for our crops. I know a lot of you have looked at the wheat this past week and have noticed the wheat fields with yellow areas. My gut feeling is that we are seeing the results of environmental stress. I would say that about 50% or more of our wheat fields have yellow or at the very least light green patches across the fields. It seems to me that a lot of those spots were on side-hills. I know that several producers were concerned that these spots were disease, but in reality it is more environmental. Most is a simple lack of nitrogen or at the very least tied up nutrients, including nitrogen. I know that most people put on what they thought was adequate N, but others assumed that wheat on soybeans didn’t need much nitrogen. Still others have told me that they put on more N this year than usual. Let’s assume that it is a lack of N causing the anomaly. Lack of N symptoms are primarily caused by three things: under-application of N fertilizer needs; leaching of nitrate after heavy rain or above average rainfall or perhaps runoff from heavy snows; or loss of N as a gas after water ponding (sound familiar?) or in compacted soil sites. It may also be because we just haven’t had the growing degree days and warm sunlight needed for photosynthesis and thus the stress expression. I think in most cases, let Mother Nature work. Good growing conditions, warmth and sunlight are the best medicine. Disease in Wheat? I think we are starting to find some signs of disease in our wheat. I have found some powdery mildew on lower leaves, but primarily in irrigated wheat fields. In those cases, it is recommended that you consider spraying your fields with a fungicide at flag stage if the mildew persists. Speaking of flags, the bulk of the wheat fields I have looked at are actually in early flag stage. We are going to see flags waving proudly across our wheat fields this coming week. That means that boot stage is very close, in fact I have found some heads migrating up the stems in the southern portions of our region. It won’t be long! We are starting to see Tan Spot, Septoria Leaf Blotch, and Leaf Rust and some Stripe Rust has been reported. With the high degree of dew in the mornings and if we eventually see some warmth, conditions will be ripe for fungal disease. Take a moment and walk through your fields, kneel down and take a look at the lower leaves, grab a flag leaf and hold it up to the sun. You may be surprised at what you see or hopefully don’t see. If you are not quite sure of what you are looking for, please feel free to give me a call or stop in. I put together a pictorial guide that may be of some help. You may also want to consult http://cropwatch.unl.edu for weekly reports and information on wheat and other crops. The thing to remember is that the flag leaf is responsible for 75% of your potential yield, so that is what we have to check and protect. Here’s hoping that your flag leaves are bright, green and clear. Last but not least….. Check your Alfalfa: The alfalfa looks great, but you may want to do a sweep, I am getting reports of weevil and pea aphids working in alfalfa fields, especially in the southern parts of Nuckolls, Webster and Franklin Counties. Oh, why not? The preceding information comes from the research and personal observations of the writer which may or may not reflect the views of UNL or UNL Extension. For more further information on these or other topics contact D. A. Lienemann, UNL Extension Educator for Webster County in Red Cloud, (402) 746-3417 or email to: dlienemann2@unl.edu or go to the website at: http://www.webster.unl.edu/home