Hands On Digital Data Managment Demonstration at Winter Wheat Workshop

Doug Johnson. Extension Entomologist, University of Kentucky

Grain Production Colleagues:

You are probably aware that the UK Wheat Science working group will be holding its annual Winter Wheat Workshop on January 6, 2015 at the Christian County Cooperative Extension Office.

(Note: this is a change of location from the original announcement.)

This year a part of the program will include two out-of-state guests, Dr. Brian McCornack and Dr. Wendy Johnson, from Kansas State University. They will be presenting a true workshop, with hands-on activities of interest to not only small grain growers but also corn and soybean growers. After all, many of Kentucky's grain farmers produce two and some, all three of these crops. In any case, at this Wheat workshop, the techniques Brian and Wendy will discuss have application to all our grain crops.

Palmer Amaranth on the Move in Kentucky

JD Green and Jim Martin, Extension Weed Scientists, University of Kentucky

Fig. 1 Young Palmer amaranth plant

Palmer amaranth (Amaranthus palmeri) continues to march across Kentucky. Initially this weed was thought to be present primarily in the west end of the state (Purchase region), but sightings have been reported within several Kentucky counties that border Tennessee and the lower Ohio River in the past few years. Last year Palmer amaranth was found on a farm in Hardin County and two additional fields in Mercer and Garrard counties. Last week a population of this weed was discovered in a corn field in Shelby County. These sightings would indicate that Palmer amaranth is a growing threat to grain crop production within the state.

Armyworm & Cutworm Moth Flights Rather Ordinary

Doug Johnson, Extension Entomologist, University of Kentucky

Black cutworm moth

Capture of both armyworm and cutworm moths have decreased during the previous trap week. At present the data indicate that neither pest is set for a big outbreak. Of course this can change especially if we get a sustained week of good weather. This does not mean that there are no pests around, there certainly are. Nevertheless, flight patterns compared to the rolling five year average do not show any sign of an elevated risk of outbreak.


 

Armyworm moth

Even though we have a good outlook for the short term we still need to remember that “only about 15 percent of corn has been planted which is well behind last year’s 73 percent and the five year average of 32 percent” (KY Weekly Crop & Weather Report Apr. 22, 2013). Remember, both black cutworm and armyworm are migrating to KY from more southern states, and the timing of their migrations are dependent upon temperature just as are planting and corn development. So it is still very possible that larger populations of either or both of these pests could show up in the early vegetative stages of corn development.So, for the moment things look good, but one best pay attention to future developments.

Tracking moth flights isn’t your only preparation option. With both insects but black cutworm in particular providing a weed free seed bed for at least two weeks prior to planting can make a big difference. Early preplant herbicide programs have shown a positive impact in the prevention of cutworm and common stalk borer infestations. Removing weeds especially grass weeds by whatever mechanism, ahead of planning is a good strategy for these early arriving insects.

Armyworm Flight Begins

Doug Johnson, Extension Entomologist

 

  Figure 1. Armyworm moth Spring must really be here as armyworm (aka true armyworm) moths have taken flight. Only a few moths have been captured thus far, but it does signal the beginning of insect season in the field crops and the current year’s capture is in line with the outbreak year of 2008. It is still too early to get real excited but important enough to be aware.

In Kentucky, armyworm can be an important pest of corn and wheat. Corn products that contain a Bt trait that provides protection from caterpillar feeding (See: Insecticide recommendations for corn:   http://pest.ca.uky.edu/EXT/Recs/ENT16-Field%20corn.pdf, pages 6-7) will likely be protected. However, non-Bt types including field corn refuge, popcorn, food-grade corns, and sweetcorn along with wheat will be at risk.

We are several weeks from any damage caused by armyworm as the adult moth is not the damaging stage. Monitoring this stage just gives us a “biofix” or heads-up that the pest is about. It is the caterpillar in which we are interested. You may want to check the flight graphs each week for the progress in this population. These may be found at:  http://www.uky.edu/Ag/IPM/ipm.htm. It only takes a few seconds to check and this can give you an idea of the relative risk of this pest for this season. On the graph you can see displayed the current year’s capture (green), the rolling five-year average (blue), and known populations that have resulted in outbreaks (red and/or black) This will give you a rough estimate of the current year’s relative risk. As these graphs represent moth flight, the relative population size can be seen before the damaging stage, the caterpillar, develops.

If populations appear to be indicating an elevated risk, I will use a temperature-based model to predict when the caterpillar stage will appear. This model will NOT predict which fields will be infested. One must scout fields to know if the armyworm is present, but the model will provide an estimate of when the field should be scouted. Remember, the model predictions will be based on the capture and temperatures at the UK-REC in Princeton (Caldwell Co.) KY. In areas to the south and southwest of the UK-REC caterpillar development will be ahead and areas to the north and northeast of the UK-REC will be a bit behind.  I will post, and you may review, the results of these model runs each week in this publication. So, if you are the pest manager for wheat or corn this spring, keep yourself tuned to this outlet for “Early Warnings” about this pest.