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).
Crop Updates: It was nice to see corn greening up and getting some growth this past week! Also on people’s minds is the 45 day post-planting application deadline for RUP dicamba herbicides. The announcement that Risk Management Agency (RMA) adjusted the 2019 final haying and grazing date from Nov. 1 to Sept. 1 for prevented planting this year opened up additional options for our farmers affected by flooding and/or excess rain. An additional option was that “silage, haylage, and bailage should be treated in the same manner as haying and grazing this year. Producers can hay, graze or cut cover crops for silage, haylage or baleage on prevented plant acres on or after September 1 and still maintain eligibility for their full 2019 prevented planting indemnity.”
So how did this change things? Many I talked with, including my family, were originally planning on going with cool season covers like oats planted the first week of August. However, with the ability to harvest a cover crop for forage on Sept. 1, interest increased in utilizing warm season cover crops. For those planning on haying, our forage specialists recommend using millets. The regrowth after haying could then be used for grazing in the late fall/winter. They also said if you’re planning on a mix, don’t add brassicas into whatever you decide to hay as they don’t dry down and tend to create a moldy spot within hay. If you’re looking at grazing only, sudangrass, sorghum sudan, millets, and/or mix with other species are great options. Forage sorghum is a great option for silage.
The other consideration is that some of this ground going into prevent plant already had PRE herbicides applied, making legal options for cover crops that could be grazed or hayed difficult. So Friday was kind of a crazy day for me walking people through options. Honestly, sometimes corn or milo for silage ended up being the most feasible option based on labels. There are also acres of corn and bean fields that were drowned out due to recent flooding and are now considered a “failed crop” by FSA. Herbicides that were applied can make planting covers in those fields difficult too. Some farmers had contracts with seed companies providing free seed for replant. Thus, once again, corn for silage seemed like a feasible and economical option. So, I called Jeff Peterson at Seward Co. FSA to see if this could be an option. He said that it would be a feasible option in 2019 if it was also approved by the person’s crop insurance agent. The first step is to contact your crop insurance agent to discuss your options for prevent plant and/or failed crop. Then go to your FSA office and fill out their form for failed crop and/or prevent plant. Your crop insurance company may require a letter from Extension stating that corn can be used as a forage crop for silage. Again, it will be important to talk with your crop insurance agent and your FSA office about your options for the fields in your counties as I can’t guarantee these are options for every situation.
Tree Problems: The rain and humidity have allowed for numerous fungal diseases on our evergreen and deciduous trees. On deciduous trees, leaves with black/brown spots may be found. We don’t typically recommend fungicides for them and if the diseases get bad enough, the leaves may eventually fall off the trees early. A new flush of leaves typically follows 10-14 days later. On evergreen trees, we’re seeing a number of needle blights and shoot tip blights. We do recommend fungicide applications for them (typically in April or May). However, it is recommended to repeat them every 3-4 weeks when frequent rains occur. Product options for most evergreen diseases include chlorothalonil or a product containing Copper that is labeled for evergreen tree diseases. Bordeaux mixture is often recommended, but I have a hard time finding anyone that carries that.
Also, be checking trees for bagworms. They’re later this year and just forming new bags. In order to see them, what I do is walk up to the trees (especially cedars or spruces) and just watch the branches for any movement occurring on them. If you’ve had a bagworm problem in the past, what you’ll see is tiny, new brown bags moving as the larvae is building a new bag. I have more info and a video to help visualize what to look for: https://jenreesources.com/2015/06/27/bagworms-in-evergreens/. The best time to spray them is when the bags are less than ½ inch in size. More info and products can be found here: https://go.unl.edu/rgju.