Extension Update by Gary Zoubek [June 28, 2012]

Coming Events
July 12, 2012 – 9:30 a.m. – Herbicide Resistant Weed Management Field Day, David City
July 23, 2012 – 7:00 p.m. – Extension Board Meeting, Extension Office, York

Cropping Update
For the second week in a row it was nice to get some more rain.  We had right at an inch for the week!  The ETgages that I’ve been monitoring dropped between 1.65 – 1.70″ for the week.  The early planted corn field I’m monitoring is in the 12-13 leaf stage.  The crop coefficient for 12 leaf corn is .88, so for the week we used 1.50″, so we lost a little ground for the week considering the rainfall we received.  To estimated crop water for various stages of corn, we multiplying the crop coefficient for your crops stage of growth by the ETgage drop for the week!

As your crop continues to grow, we need to remember that the root system is also expanding below the soil. When corn is at the 14-16 leaf stage, we’re using a rooting depth of 2.5’ to schedule irrigations; at silk stage, we’re use a rooting depth of 3’ and at the blister stage and beyond, we’re using a rooting depth of 3.5’.

Different soil types store different amounts of soil water, our Hasting Silt Loam soil hold about 2.2”/foot of soil, but we really utilize only 50% of it, so we have 1.1”of available water/foot or 3.3” for a three foot profile!  Since we all have crops of different stages of growth and the ET rates vary across the state due to temperatures, wind and humidity, it important to monitor your soil water along with ET estimates to schedule irrigations in your field or fields!

Have you figured your well’s capacity?  Chuck Burr, Extension Educator shared a good conversion factor for you to remember; a 450 gallon per minute well applies 1 acre-inch of water every hour, so if your well pumps 900 gpm, you are applying 2 acre-inches every hour.  For a 133-acre pivot, you can apply about 1.1 inches of water every three days.  Calculate your application capacity and keep in mind how much stored soil moisture you have when scheduling your next irrigation.

It sounds like the forecast is for the warm or should I say hot temperatures to continue for the next few days!  If your humidity’s stay up, hopefully it will be a little easier on the crops but harder on us!  Tom Hoegemeyer, Chuck Burr and I have prepared a couple articles for CropWatch.  They include: “How Does Hot, Dry, Windy Weather Affect Corn Plants Now?” and “Managing Soil Water with Higher than Normal Temperatures.”  You can check them out along with the latest forecast at CropWatch:  http://cropwatch.unl.edu.  This week’s edition also includes an update on Goss’s Wilts as well as information about the upcoming herbicide resistant weed management field day.

Our UNL Weed Science Extension Specialists and Educators have put together a field day July 12th  in the David City area to discuss limiting the development and spread of herbicide-resistant weeds.  Guest speaker will be Jason Norsworthy, associate professor in the University of Arkansas Department of Crop, Soil, and Environmental Sciences. Norsworthy, a national speaker on the problem of herbicide resistance, will address how glyphosate-resistant weeds are changing agriculture in the southern U.S. and what that may mean for weed control in the northern Great Plains.

The program will begin with registration at 9 a.m., a welcome, and tours beginning at 9:30 a.m. The keynote speaker will be during the noon hour, with the program expected to end by 1:30 p.m.  The event is free but preregistration is required by July 6 so plans can be made for the complimentary meal, teaching resources, and tour logistics. Register online at http://agronomy.unl.edu/weedresistmgt

Topics include:
Glyphosate Dose Response. See how resistant weeds respond to increasing rates of glyphosate.
Management Systems. Study various herbicide programs and their effectiveness at controlling a glyphosate-resistant weed population.
Liberty Link Soybean. See how Liberty Link Systems can be used to sustainably manage weeds.
Dicamba-Resistant Soybean. View demonstrations of how dicamba-resistant soybean can provide another post-emergence tool for weed management.
Carrier Rate. See the impact of carrier rate on several herbicides. This stop will also address the importance of effective herbicide applications to manage the development of weed resistance.
This program is sponsored by UNL Extension and the Nebraska Soybean Board. Directions to the David City location: From Hwy 15 in David City, turn west on East A St., then continue west for 2 blocks and look for the UNL field signs.  It should be a great session, I hope you’ll plan to attend!

Yard & Garden
The ETgage in front of our office with a #30 grass cover dropped 1.35″ this past week!  So for the week, we averaged .19″ per day!  The good news is we received nearly 1” of rain, so we only use .35” for the week! rain!  

County and/or State Fair Volunteers Needed
It’s hard to believe, but the fair season will soon be upon us!  I could sure use a few volunteers to help us in Ag Hall and I’m sure we have other spots that could use some extra help.  If you’d like to help contact me at 402-362-5508 or email me at gzoubek1@unl.edu!

The Nebraska 4-H program is also seeking volunteers to help with exhibit entry day, judging, and serving as 4-H exhibit building hosts and greeters. Volunteers will be needed for educational activities in the 4-H building, serving as the Lil’ Green Mascot and assisting with all 4-H contests and events throughout the fair. State Fair 4-H volunteers will receive a fair pass for the day(s) they volunteer.

If you’d like to help at the Nebraska State Fair in the 4-H area, check out this link: http://4h.unl.edu/nebraskastatefair.  Check out the volunteer information link!