Category Archives: hail
*The York and Seward County Extension offices are now open to the public. We ask that visitors please wear a mask when entering the buildings.*
This past week was interesting to say the least! For those who experienced hail and/or wind damage, the following site provides guidance via information and videos for early-season hail damage: https://go.unl.edu/u5ns. We do say to be patient and wait 4-7 days to determine recovery and warm temps can help. For home owners, there was also a great deal of tree and plant damage. Make clean pruning cuts and don’t treat/paint over cuts, don’t add fertilizer, and leave as much leaf area as possible.
Most of this week’s questions centered around soybeans. The past two weeks, the
majority of my soybean questions have been around emergence problems. Two common things I’m finding: many were planted around May 18-19 and they have a great deal of PPO-inhibitor injury to hypocotyls. In touching base regarding what we were seeing, John Mick with Pioneer shared that some soybean varieties are more sensitive to PPO-inhibitor injury. ‘Sensitive varieties’ means later on plants appear stunted and chlorotic in appearance. These plants also tend to have wavy leaves with some leaf cupping, which may have been mis-diagnosed as off-target growth regulator injury in the past. I’ve seen those symptoms for several years but just told people the plant was working to metabolize the pre-emergence herbicide and it was most likely taking longer due to the environmental conditions at the time. So, in a way, it was correct, but now we can all be more aware there are sensitive varieties to PPO-inhibitors. Thus, it’s important to talk with your seed dealer/agronomist about their variety ratings (if they exist). If planting a sensitive variety, it’s better to apply your pre-emergence application a week or so before planting to reduce the herbicide load on that germinating seedling. I’ve put a lot more explanation and pictures in this CropWatch article and the pics also on my blog.
The pre-emergence products did a great job for the most part. Thus, a common
question/discussion this week was around spraying essentially ‘contact’ herbicides in the absence of weeds. Could appreciate those thoughts. Regardless if the farmer wanted to apply glyphosate, liberty, or dicamba, we did talk about the importance of spraying earlier than one thinks is necessary and the need for residual products. I was going to share more about that here, but Amit Jhala wrote a very good article in this week’s CropWatch at: https://go.unl.edu/y3r8. He explains which products are options to consider at this point depending on if you have emerged weeds or not, what growth stage they can be applied, and some label restrictions. There’s a picture on my blog for soybean development stages. The cotyledons are not counted. The unifoliolates are counted as V1 only when the trifoliolate leaf edges above them are no longer touching. This continues up the plant. New nodes with leaves will be produced every 3.75 days. Note that early planted soybean may flower soon; they don’t have to wait till June 21 (longest day of year) to do so.
Because of that, for those near the 45 day window for post-dicamba application to soybean, be sure to check fields as the label states 45 days after planting or R1 (at least 1 flower on any node), whichever occurs first. Follow label instructions and I’m also recommending documenting development stage via picture/video on all post- applications to crops this year. Regarding use of soybean dicamba, Nebraska Dept. of Ag Director Steve Wellman stated, “The Nebraska Department of Agriculture has not issued a stop sale order and will enforce the sales and applications of these products as they are currently registered in Nebraska.”
Thistle caterpillars are being observed in some early planted soybean fields. Threshold for pre-flowering is 30% defoliation.
Corn post-herbicide applications: Said I’d share on this, but ran out of room; I
wrote a CropWatch article here: https://go.unl.edu/jz9v. Recommendations for any applications this year: Go into the field (beyond the endrows) and document growth stage of the plant via picture/video using the leaf collar method and/or split stalks (once reach V6 due to leaves sloughing off). Do this before any applications are made to the field. If the growth stage isn’t correct for the application, don’t spray. How I explain the split-stalk method of development staging: The growing point emerges above ground around V6. Dig a plant without breaking the stalk. Carefully split the stalk down the middle through the root ball. At the base of the stalk is an inverted triangle that contains Nodes 1-4 (but they can’t be differentiated). Next look for the white area above that (about ½-3/4”) followed by the next visible band. The white area is the internode with the band being the 5th node (V5). There’s about an inch of internode between V5 and V6. After that, internode length is more dependent upon air temperature instead of soil temperature. Every leaf is attached to a node. Pull off the fully collared leaves and follow them back to where they break off at a specific node. Count the nodes on the stalk to the highest collared leaf that breaks off at a node to determine the growth stage.
Crop Update and Hail Damage: While I don’t remember numbers as well, calendar dates are something I tend to remember. And, in agriculture, there’s numerous dates that accumulate over one’s life from hail, tornado, blizzard, flood, and wind events. I was reflecting on the Aug. 6th hail storm that occurred in Merrick, York, and Seward counties in 2018. This past week on August 7th, some woke up to hail/wind damage in Adams, Clay, and Nuckolls counties. The tree damage was incredible. Michael Sindelar, Clay Co. Educator, and I surveyed damage a day later. My estimation of the worst hit crops: corn around 80% defoliation with varying percentages of greensnap above/below ear and soybeans around 50% defoliated/broken off/with at least 50% pods on the ground. Where hail stones hit the ears, the kernels are mushy and mold is already setting in on corn at milk stage. There’s also mold setting in on soybean pods hit with hail stones. It’s hard to receive crop damage any time. The good news is that nothing appears to be a total loss; the majority of what we looked at was less than 40% defoliated and in general, the hail did not seem to penetrate the stalks, thus early stalk rot doesn’t appear to be setting in. Pictures at https://jenreesources.com.
Tree Problems: The majority of my questions the past 10 days were regarding tree leaves turning yellow and dropping from trees. They look stark against green grass. In general, what’s happening is the fact that we’ve had high humidity for a period of time now and we’ve had rain throughout spring and summer. Fungal pathogens thrive in these conditions. So, ornamental/flowering pears have pear rust; crabapples and apples have scab and also cedar-apple rust (depending on varieties); maples, ash, sycamores are showing anthracnose; and a number of other fungal leaf spots are observable on shade trees in general. Evergreen trees show various fungal needle spots. Ultimately, we don’t recommend doing anything for these diseases this time of year. We typically don’t recommend to spray shade trees in general, but fruit and evergreen trees should be sprayed in the spring if fungal diseases have occurred in the past. So, fungal diseased leaves may drop early and you may or may not observe a new flush of leaves yet this year. These fungal diseases won’t kill deciduous trees. They can kill evergreen trees over a period of years.
Oak leaves turning brown in clusters was also observed this past week. Sometimes
browning of leaves can be due to a fungal disease called anthracnose. Most of what I’m seeing, I believe, is environmental. It could be due to changes in hot/cool and periods of heavy moisture followed by lack of moisture on trees that had a huge flush of leaves due to moisture this spring. I really don’t know the cause for sure, but it doesn’t appear to be disease related from what I can tell. We wouldn’t recommend doing anything for the trees at this time.
UBBNRD Public Hearing: The Upper Big Blue NRD will hold a public hearing and informational open house on Aug. 19 at 7:00 p.m. at the Holthus Convention Center. The purpose is to receive comments on proposed changes to District Rule 5 – Ground Water Management Area Rules and Regulations. A complete copy of Rule 5 and the proposed changes are available at the district office and at www.upperbigblue.org/publichearing. The public will have the opportunity to learn more about these proposed changes and their effects, and address NRD board members about their concerns or support.
The proposed changes would stipulate that an approved nitrification inhibitor must be applied at the manufacturer’s recommended rate with pre-plant nitrogen fertilizer in the following situations: The application of anhydrous ammonia prior to March 1; The application of all nitrogen fertilizers other than anhydrous ammonia after February 29. In addition to these requirements, in Phase II and Phase III areas pre-plant application of nitrogen fertilizer shall not exceed 120 lbs. per acre. The remaining nitrogen fertilizer may be applied post plant. Prior to applying nitrogen fertilizer, but no later than April 1 of each year, each operator in the management area will be required to report information regarding the use of best management practices. For more information, visit www.upperbigblue.org or call (402)362-6601.
York County Corn Grower Plot Tour will be held Aug. 20th from 5-7 p.m. at 1611 Rd. 14 east of York. Pizza and refreshments will be provided and check out the latest hybrids. Guess the winning yield without going over and win a $50 gas card. All are welcome!
*End of News Column. Hail damage photos below.
Prevent Planting and Herbicides for Cover Crops: This past week, corn for silage was approved as a cover crop in prevent plant situations, primarily because of the herbicide restrictions on cover crops for forage. A team of us wrote an article about how to understand herbicide rotation restrictions and also shared the information from NRCS regarding corn as a cover crop in this week’s CropWatch. You can see these and more articles about soybean gall midge and Japanese beetles at http://cropwatch.unl.edu.
Hail Damage: For a ‘slight chance’ of rain, it was interesting to have the hail and 4” of rain in the gauge Wednesday morning! It appears we had hail from the York area through Cordova area and I heard there was also hail in Butler and Platte counties. The larger hail appeared to have damaged crops into Kansas through Superior, south and west of Lawrence through Blue Hill and Holstein. What was encouraging was not even 24 hours after the storm, signs of recovery could be seen in corn and soybean. Warm temps, no rain, and sunshine make all the difference in recovery after hail compared to cool, wet, cloudy conditions. I went back to look at fields in the southern tier of counties into Kansas and in York area southeast on Friday and was further encouraged by the regrowth. You can view photos on my blog at https://jenreesources.com. The bruising on stalks and stems can allow stalk rot to set in on corn and soybean stems to become brittle and break off with wind…so keep this in mind towards harvest and plan to get these fields out first if possible. What’s hardest is wheat fields that were nearing harvest that shattered or were totaled due to hail. Also difficult is the fact we’ve lost so much canopy in crops at the peak of palmer growth for those who have fields with palmer problems. And speaking of palmer, a reminder of the palmer amaranth field day near Carleton on July 10th. View herbicide options for palmer control and listen to keynote speaker Dr. Jason Norsworthy from the University of Arkansas. Registration at: http://agronomy.unl.edu/palmer.
So, this may sound crazy, but I was curious about the potential of interseeding a cover in these corn fields with extreme canopy missing right now. I was standing in one field of V11-12 corn with all the leaves gone listening to the growers tell me how much of a palmer problem this field has, even though it is clean right now. We know from research that interseeding at this growth stage typically doesn’t work due to canopy closure, but I’m wondering if it could help with weed pressure since the remaining leaves may be more upright and may not completely shade the rows? The keys to this consideration would be the herbicides used and considering rotation restrictions if you plan on using the stalks and cover for forage after harvest. If you don’t plan to use the cover for forage, there wouldn’t be restrictions as you’d assume planting at your own risk. We can’t predict if it will keep raining for non-irrigated fields. It would also be wise to talk with your crop insurance agent about this.
Fungicides in Hail Damaged Crops: Several have asked about fungicide use on hail damaged crops. There’s no good research to support this and fungicides only control fungal diseases. Bacterial diseases such as bacterial leaf streak and Goss’ wilt are favored after hail events. We’ve already seen both of these diseases in this part of the State due to heavy rains. Fungicides at some point may help with stalk strength with all the bruising and we may need fungicides later this season for disease if the humidity and rains continue.
The available research had fungicides applied at tassel instead of the earlier growth stages we’re currently at. ISU did a one-year study to simulate hail damaged corn at tassel stage within an average of 3 or 8 days post-hail. They didn’t find the timing to provide any yield effects. They also didn’t find a statistical yield increase (90% confidence level) in fungicide application to hail damaged plants vs. those which weren’t hailed (although they also reported a numerical yield increase in 12 of the 20 fields). A study was also conducted by Carl Bradley at the University of Illinois in 2007-2008 to evaluate the effects of fungicide applications at tassel in simulated hail-injured corn on gray leaf spot severity and yield. In that study, fungicide applications did not statistically increase yield when applied on corn that was damaged to simulate hail injury.
If you’re considering a fungicide now, you could consider an on-farm research study depending on equipment, ability to get in the field, and crop height. Spray fungicide in enough width to complete 2 combine passes. Then skip an area for 2 combine passes. Then treat again and repeat across the field. View: Fungicide Protocol for Hailed Corn and Soybean. Some talking about this wondered about aerial applications. If we had enough people who left a check, we could look at combining the data to make up for lack of reps in one field. Please let me know if you’re interested in either of these options.
Butterflies and Soybean Defoliators: Painted lady butterflies and others like sulfur butterflies can be seen flying around as they’re emerging from soybean fields. I really wish they’d move on but I’m seeing butterflies in my gardens now too, so we’re just going to have to keep scouting fields. There’s also a lot of yellow striped armyworms out there of various larval stages. If your soybeans don’t seem to be growing or you seem to be losing canopy beyond hail damage and ‘burner’ herbicides, be looking for various larvae. In this heat, if you have a lot of residue in the field, they may be hiding under it, so be sure to look there too if you have a spot in the field especially affected.
NOTE: End of News Column. Photos below to document recovery.
Soybeans with new growth seen in axillary buds and/or main shoot within 24 hours of June 26 hail storm (first two photos) and 3 days after hail storm (last two photos). Soybeans were V4 to R1. Note, temperatures were hot with sun and dry conditions post-hail.
Wheat grain shelled from heads and broken heads in both early and later planted wheat. Warm season forages may be a good option to consider in totaled out wheat fields.
First photo is corn west of Lawrence on July 26 and showing regrowth in second photo 3 days later. Third photo is corn near York on July 26 showing growth in whorl not damaged. Last photo is worst hail damaged area I saw near Webber, KS. There was nothing left of soybean in the nearby fields.
Hail damage on stems may be only on the outer surface of leaves with no bruising below that (as in first two photos). Or, it can be more severe where bruising is leading to rot setting into the stem (as in last two photos).