Extension Update by Jenny Rees

Grateful for the nice weather last week for post-emergence spraying! As crops continue to rapidly grow, a reminder for proper growth staging using the leaf collar method. A collar develops at the leaf base near the stalk after each leaf fully expands. Think about collars like the collar on a button-down shirt. The collar flares slightly at one’s neck, just as a true exposed leaf collar flares at the base of the leaf at the stem. Start counting leaves at the base of the plant with the smallest rounded-tip leaf with a collar as #1. From there count every leaf with a true collar. Leaves that are still wrapped in the whorl around the main stem without exposed leaf collars are not counted. You can also paint a certain leaf of the plant, such as V5 or V6, inside the field (not endrows), so you can continue to count leaf collars as the lower leaves start to slough off.

It may also be helpful to get irrigation scheduling equipment installed soon. For those with watermark sensors, we’d recommend to soak the sensors in water for 24 hours and then read them to make sure they’re under 10 kilopascals. Then allow them to dry out to 199. Before installing, soak again (but only needs to be like 5 min.), and they should still read less than 10 kpa before installing. Last year I made a video regarding installation if it can help (https://youtu.be/4r5gn2pvvB4). For those looking for telemetry options, there are options available for watermark sensors too. One option from Servi-Tech is called the Profiler through their STEPS program. Another option is from Irrometer who makes watermark sensors. For those who use ET gages, remember to use distilled water when filling the main column, prime the small tube with the stopper and ensure there’s no air bubbles, and remember to fill the ceramic top with water before adding the stopper. With Dr. Suat Irmak’s departure from UNL to Penn State, the ET gage site has been decommissioned. ET information can also be found at UNL’s CropWatch website at:  https://cropwatch.unl.edu/et_resources.

Weed Management Field Day: Growers, crop consultants and educators are encouraged to attend Nebraska Extension’s Weed Management Field Day from 9 a.m. to 1 p.m. June 23, 2021 at the South Central Agricultural Laboratory near Clay Center. The field day will include on-site demonstrations of new technology and new herbicides for corn, soybean, sorghum, and sweet corn. An early morning tour will focus on weed management in soybean and sorghum followed by a tour of weed management in field corn and sweet corn. Field experiments will provide information for weed control options with various herbicide programs. Three Certified Crop Advisor (CCA) Continuing Education Units are available in the integrated pest management category. There is no cost to attend the field day, but participants are asked to preregister at http://agronomy.unl.edu/fieldday. The South Central Agricultural Laboratory is five miles west of the intersection of Highways 14 and 6, or 13 miles east of Hastings on Highway 6. GPS coordinates for the field day site are 40.57539, -98.13776.

Bagworms: Have received a few questions regarding if bagworms have emerged yet. The very cold winter hopefully may have impacted bagworm survival since they weren’t as insulated on trees. I haven’t checked trees yet, but here’s a trick to help know. If you have last year’s bags on your trees that are sealed (don’t have an open hole at the top), you can pick off some bags, place them in a ziplock bag, and place it outdoors on the south side of your house. When/if you see larvae emerge, it’s a good indication to start checking your trees in the next weeks. The larvae are really small and hard to see. Stand still and watch the tree. If bagworm larvae are present, you will see very tiny movements as they begin the process of building new bags. I have pictures and a video at: https://jenreesources.com/2015/06/27/bagworms-in-evergreens/. For more info., please see: https://go.unl.edu/rgju.