On-Farm Research Protocols:
Hail and wind damage occurred throughout the area I serve last week. Overall, I’ve been encouraged by the regrowth observed on corn and soybean plants affected by the June 14th storm. We were blessed with warmer weather and sunshine that allowed for regrowth to occur in many situations other than some fields around the Deweese area.
You can look for regrowth on leaves within the whorl of corn plants and on the axillary buds of soybeans. Even what appeared to be soybean ‘sticks’ may show regrowth by now.
The concerns I have for plants affected by these storms is all the stem bruising on both corn and soybeans and the potential for bacterial diseases to affect corn.
For those of you affected by June 16th storms, we recommend to wait a week to assess damage and any decisions. I realize we’re also at a critical stage for replant decisions as we continue later in the season. Ultimately, decisions need to be made on a field by field basis.
- CropWatch Hail Damage Resources
- Resources from storm damage in 2014
- Fungicide Use After Hail or Wind
There’s no good research to Dr. Tamra Jackson-Ziems or my knowledge to support this. Fungicides only control fungal diseases. Bacterial diseases are favored after hail events and we have already seen bacterial leaf streak in the area prior to the storm. From past-years’ experience of prior wind/rain events, we can expect to see more of it in about a week. Fungicides won’t help that disease nor Goss’s wilt which is another we often see come in after hail events.
However, if you’re considering this, I’d like to have several farmers prove it to yourselves with on-farm research this year so we do have data for the future. It’s this simple. All you do is 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. Fungicide Protocol for Hailed Corn and Soybean. Please let me know if you’re interested in this!
Timing of fungicide app: ISU did a 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 increase in 12 of the 20 fields.
Herbicide application: I spoke with Dr. Amit Jhala, Extension Weed Specialist for his thoughts regarding this. He said ultimately herbicides shouldn’t be applied to stressed weeds in order to achieve greatest efficacy. The concern for many including me right now is how well the weeds survived the hail and how quickly they are regrowing compared to the damaged corn and soybeans. This again is a field by field assessment regarding how well your corn and soybean regrowth is occurring and how rapidly your weeds are. I watched one palmer plant in one field after June 14 storm: 1 day post hail and 2 days post hail put on two sets of leaves in that time period. I also took pictures of soybeans reduced to sticks while waterhemp in that field was virtually untouched. I think many are trying to wait 5-7 days post-hail to apply herbicides but there were some fields I was suggesting to apply over the weekend with the recovery already occurring and less damage.
Corn replant: The biggest concerns with corn would be stands, eventual stalk rot/downed corn due to stalk bruising, and bacterial diseases. I’ve essentially watched stands reduced over the course of the growing season after early-season hail storms mostly due to bacterial diseases like Goss’ wilt. It will be important to have your crop insurance adjuster look at the field again prior to harvest. Splitting the stems of damaged plants across the field can help you assess any damage to growing points; they should be white/yellow and firm not brown and soft. Tattered leaves that are wrapped around the whorl should eventually turn brown and break off with the wind. They can sometimes impede new growth from the whorl as well though.
Soybean replant: Soybeans can compensate so greatly for reduced stands. From hail at this stage in the past, we’ve said to leave stands of non-irrigated at 60,000 plants per acre and irrigated at 75,000 plants per acre. Some soybeans reduced to sticks are shooting axillary buds. My biggest concern on soybeans is the stem bruising which isn’t accounted for in hail adjustments. If you want to prove replanting or not to yourself, consider slicing in soybeans next to the old row in strips across your field. Be sure to inoculate the soybeans and be sure to take prior stand counts. Soybean Replant Protocol.
There’s nothing like doing these studies and seeing the results on your own ground or from your peers’ farms. In 2006, I worked with a grower in the Lawrence, NE area on a non-irrigated soybean plant population study where he tested seeding rates of 100K, 130K, and 160K seeds/acre. He received hail at the cotyledon stage and because he was non-irrigated, chose to leave the stand. His actual stand counts were 74.4K, 89.4K, and 97.9K plants/acre respectively for the previous mentioned seeding rates which resulted in yields of 38.6, 40.6, 42.7 bu/ac respectively. Another soybean replant study occurred near Columbus, NE where the grower had an average plant stand of 75,000 plants per acre on June 11th. He chose to replant five strips across the field at a diagonal to the existing rows. The replanted soybeans ended up yielding 1 bu/ac less than the original plant stand. I realize it’s hard to want to do these extra steps for on-farm research, but this is why it’s important; it’s the way to answer these questions for yourself! Please contact one of our team members if you’re interested in on-farm research this year!
Memorial Day storms hit us again this year, this time with the EF2 tornado in Edgar. I checked NE Rain, and for the month, Clay County received between 5.9-9.7″ of rain with nearly 3/4 of that coming in the last 6 days !
Even with the saturated soils and localized flooding, there is still potential for drought. It was this way last year at the end of May before the rains shut off in early June.
I’ve received questions regarding potential storm damage to crops. Normally I’ve found that waiting a week helps with determining regrowth and decisions. Overall, we’re fortunate that crops were so small. Much of the corn was V1-V3 and the soybeans were anywhere from not planted to cotyledon stage. The majority of damage occurred where emerged plants were silted over with soil and/or residue, standing in water for periods of time, of left with stems due to high wind and/or hail.
According to Purdue University Agronomist, Bob Nielsen, it takes around 48 hours for oxygen to be completely depleted from saturated soils. Plants that are emerged above the water have a better chance of survival than those below it; however, it’s hard to tell exactly how long plants can survive in those conditions. We also have several areas where plants were standing in water for a few days, the water receded, and now they’re standing in water again. Only time will tell how those plants will fare.
Because the growing point of affected corn plants is below ground, in many situations, plants should recover if the growing point remained healthy. Hopefully only small areas will need to be replanted. For crop insurance decisions and options, please check out the following CropWatch article.
Some emerged soybeans that were at cotyledon stage have been reduced to stems leaving gaps between healthy plants. Soybean plants can compensate for reduced populations; however length of gaps and final stands do need to be assessed for replant decisions. UNL on-farm research has shown less than 1.4-2.0 bu/ac yield difference between planting 90,000 and 180,000 seeds/acre. (See report.) In our research, 90% of the planted stand was achieved at both seeding rates in irrigated 30-inch rows in no-till and ridge-till fields.
Consider what was found in 2006 in one dryland field in Nuckolls County where seeding rates of 100,000, 130,000, and 160,000 seeds/acre were planted. This field was at the cotyledon stage when it was hailed. Some plant stands dropped to 67,000 plants/ac. Yield was 4 bu/ac less than in the 160,000 seed/acre planting that had a final stand of nearly 98,000 plants/ac. The average yield in the field was 40 bu/ac. While this is only one field and one year of research, it is an example of how soybean plants can compensate for reduced populations by branching and how August rains in dryland can still allow reasonable yields to be produced. Based on our on-farm research, leaving dryland stands of at least 65,000 plants/acre and irrigated stands of 90,000 plants/acre is likely a better choice than replanting, in the event that the gaps between plants are not large and are fairly even.
Many of the soybeans worst affected were reduced to stems. Last year we watched as soybeans continued to develop plumules after the hail events and soil crusting in our area. The plumule, which is the seedling stem tip and its undeveloped leaves above the cotyledonary node, may remain, but without the cotyledons to serve as a carbon and nitrogen source, development of new seedlings with small leaflets will be slow. These plants may not become competitive with surrounding plants in terms of pod and seed production. Therefore, when counting seedlings to determine plant stand, count only the seedlings that have at least one cotyledon. You can count seedlings missing cotyledons if they have large unifoliolate leaves that will soon unroll as in this picture.
we will monitor damage early next week to help with replant decisions. Overall, I feel we are fortunate that the crops were so small and crop damage does not appear to be severe other than all the pivots that need to be replaced. We will also need to watch for potential disease damage in weakened plants. For crop insurance decisions and options, please check out the following CropWatch article.