Last week I was receiving text messages from a few of our farmers about corn harvest results from damaged corn. Low levels of mycotoxins are being detected in samples thus far, thankfully.
Here’s What the Numbers Mean…
For aflatoxin, the U.S. Food and Drug Administration has set a recommended limit of 20ppb (parts per billion) for dairy animals, 100 ppb for breeding animals, and 300 ppb for finishing animals. To put this is simpler terms, a sample would need 20 affected kernels out of a billion kernels to be at the legal limit for dairy animals. So far, most samples are coming up at 5-6ppb which is very low.
For fumonisin, 20ppm (parts per million) is the recommended limit set by FDA for swine, 30ppm for breeding animals, 60ppm for livestock for slaughter, and 100ppm for poultry for slaughter. So, this would mean 20 affected kernels in a million kernels could cause a problem for swine. Again, our levels are averaging closer to 5ppm right now which are low.
Deoxynivalenol (DON) also known as vomitoxin is another mycotoxin being tested from grain samples. This mycotoxin causes reduced weight gain and suppresses animal feeding, especially in swine. Concentrations greater than 10ppm can result in livestock vomiting and totally refusing feed. FDA has recommended that total feed levels of DON not exceed 5 ppm for cattle and chicken, and 1 ppm for swine.
It is very important to sample from several places in the grain to get an accurate sample for damage and mycotoxins. It is also very important that black light tests are not used to determine the presence or absence of mycotoxins. Some of these mold fungi produce a compound that fluoresces under black light, but research has shown that this quality does not consistently predict the presence of mycotoxins (often provides false positives). Finally, before any of your storm-damaged corn is put in a bin, call your insurance agent out to get a sample!
Protecting Your Health with a Mask
There is some great information from the University of Nebraska Med Center on what types of masks to use to protect your health from molds and potential mycotoxins. Some people tend to have more sensitive immune and respiratory systems than others, so I’d highly recommend checking out these short videos.
It’s been an interesting few weeks. Last week I was continuing to receive calls about considerations for drought damaged corn. Then southern rust arrived in the area earlier last week. Followed by the tremendous August 1 storm that affected so much of our County.
is how I’ve felt these past few days-and I can’t imagine how difficult it is for you whose crops were affected! It’s just a sickening feeling walking into field after field and driving around the County seeing the storm damage every day. I’m so sorry for those of you who have lost your crops! As I look at the crops, though, I’m a little puzzled at the way things are laying, the twisted plants….things aren’t all adding up for “straight-line winds”.
In spite of how difficult things look right now, I can’t help but wonder if we were spared from something much greater?
The follow passage in the Bible has been my go-to during times of drought and difficult times in farming. I was going to share this in a drought post…but I feel it still applies with as many partial and total crop losses we’ve experienced in the area.
Though the fig tree should not blossom and there be no fruit on the vines,
Though the yield of the olive should fail and the fields produce no food,
Though the flock should be cut off from the fold and there be no cattle in the stalls,
Yet I will exult in the Lord, I will rejoice in the God of my salvation! Habukkuk 3:17-18
In the midst of trying to provide advice, it’s nice to know that God has everything already figured out and that He’s always in control. Even in the midst of this, He is always good!
The sun has been welcomed and crops are rapidly growing in South Central Nebraska! Corn right now is between V6-V8 (6-8 leaf) for the most part. Quite a few farmers were side-dressing and hilling corn the past two weeks. It never fails that corn looks a little stressed after this as moisture is released from the soil and roots aren’t quite down to deeper moisture.
Installing watermark sensors for irrigation scheduling, we’re finding good moisture to 3 feet in all fields in the area. The driest fields are those which were converted from pasture last year and we want to be watching the third foot especially in those fields. Pivots are running in some fields because corn looks stressed, but there’s plenty of moisture in the soil based on the watermark sensor readings I’m receiving for the entire area. So we would recommend to allow your crops to continue to root down to uptake deeper moisture and nitrogen.
The last few weeks we observed many patterns from fertilizer applications in fields but as corn and root systems are developing, they are growing out of it. We’ve also observed some rapid growth syndrome in plants. This can result from the quick transition we had from cooler temperatures to warmer temperatures, which leads to rapid leaf growth faster than they can emerge from the whorl. Plants may have some twisted whorls and/or lighter discoloration of these leaves, but they will green up upon unfurling and receiving sunlight. This shouldn’t affect yield.
Damping off has been a problem in areas where we had water ponded or saturated conditions for periods of time. We’ve also observed some uneven emergence in various fields from potentially a combination of factors including some cold shock to germinating seedlings.
We began applying sugar to our on-farm research sugar vs. check studies in corn. We will continue to monitor disease and insect pressure in these plots and determine percent stalk rot and yield at the end of the season.
Leaf and stripe rust can be observed in wheat fields in the area and wheat is beginning to turn. We had some problems with wheat streak mosaic virus in the area again affecting producers’ neighboring fields when volunteer wheat wasn’t killed last fall. Alfalfa is beginning to regrow after first cutting and we’re encouraging producers to look for alfalfa weevils. All our crops could really use a nice slow rain right now!
Hope to see you at this weed science field day at UNL’s South Central Ag Lab near Clay Center on July 2nd! No charge. Please RSVP to (402) 762-4403. More information at: http://scal.unl.edu.
With the recent rains in Nebraska, the potential for wheat scab has increased. This video shares more information including a fungicide table of products to consider with product efficacy ratings for scab. For more information, please check out http://cropwatch.unl.edu. Thanks to Rachel Stevens, UNL Extension Intern, for producing this video!
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.
It’s wonderful receiving the rain we did, seeing how quickly planting progress came along, and how quickly corn is popping out of the ground! Being mid-May, it’s time to get our Evapotranspiration (ET) gages out. A reminder to only use distilled water in the gages, make sure to fill up the ceramic top portion of the gage before inserting the stopper, and gently dust off the ceramic top and replace the white membrane and green canvas cover. We recommend replacing those membranes and covers each year so if you need a new one, please let the Natural Resources Districts (NRDs) or me know and we’ll get you a new one! For those of you recording ET information online, please be sure to do so consistently each week to help your neighbors and crop consultants.
Early after crop emergence is the best time to install watermark sensors. For those of you with watermark sensors, read them to ensure they read 199 kpa (dry). Then “prime” them first by soaking them for 24 hours in water to ensure all the air bubbles have been released. The sensors should have a reading of 10 kpa or below to be considered good. If they read higher than that, either continue soaking them another 24 hours and read them again, or plan that they no longer are reading correctly and replace them with others from the NRDs. Remember after soaking sensors that water moves up into the PVC pipe via capillary action, so be sure to dump the water out of the pipe as well.
When installing the sensors, be sure to install them wet, drain excess water, and look for areas that are not compacted, avoid tractor wheel tracks, and look for even spacing of plants. Carefully install without breaking off any plants (thus easier when plants are small!). It’s also important not to install sensors into extremely wet fields. What we have found is that a thin soil layer can cover the sensor when pushing it into the soil of very wet fields. When that soil layer dries, it can provide a reading of 199 saying the sensor is dry when it truly isn’t. If this happens to you, simply remove the sensor, rewet for one minute and re-install. It should be acclimated to field conditions within 48 hours. If you have any questions regarding the installation process, please let the NRDs or your local Extension Educator know. You can also view videos of the installation process and receive additional information to answer your questions.
Dr. Charlie Wortmann, UNL Extension Soil Fertility Specialist, explains the power of statistics for understanding yield and other differences and non-differences for on-farm research.
As I set here writing, we went from wearing t-shirts yesterday to receiving freezing rain and sleet today! The precipitation is much welcomed and it’s nice to see spring bulbs coming up and the grass turning green! But we’re unfortunately not out of the woods yet regarding this drought, and may not be for some time.
This Thursday, April 11, Elizabeth Killinger, UNL Extension Educator in Hall County, will be talking to us about gardening during drought. Come enjoy an evening of learning about drought-tolerant plants and ideas for your landscape! The evening begins with a light supper at 5:30 p.m. and we plan to be finished around 7:00 p.m. There will be no charge for this workshop, so please come and invite your friends and your youth who enjoy gardening as well!
Also, if you would like to bring some plants for exchange, you are welcome to do so and share with others! Please call the Clay County Extension Office at (402) 762-3644 or Jenny at email@example.com to let us know you’re coming so we can plan for the meal. See you then!
For the past ten years I’ve come across farmers who really believed in applications of sugar to reduce their pest populations. Being no research to my knowledge to prove it, I tucked the observation in the back of my head for future reference. With farmers looking to increase yields and looking to other farmers such as Kip Cullers for information, some of our on-farm research producers were curious about sugar applications in their operations with the hopes of increasing yield.
Nebraska On-Farm Research Corn Results
Using the application rates that Kip Cullers uses, one Clay County producer applied 3 lbs of sugar (purchased pallet of cane or beet sugar from the local grocery store) per 10 gallons of water at V7-V8 on corn in 2010-2011. Cullers also tanked mixed the sugar solution with a post-herbicide application like glyphosate but this producer didn’t do that. To simulate any affect of the water or driving through the field, he also drove through the untreated check spraying water only. Two years of research results showed no significant increase in yield. However, there was a noticeable difference in standability at harvest. This producer did not apply a foliar fungicide either year. When it came to harvest, this producer needed the reel in 2010 for the untreated check. Stalk rot ratings were taken using the pinch test two weeks prior to harvest. To him, the $1.25/acre of sugar was worth it to improve standability even if yield was not significantly improved. You can view the full research report here.
Several York County producers have also tried this with one producer finding a non-statistical 2 bu/ac yield difference with the check yielding better while the other producers found a statisically significant 2 bu/ac increase to the sugar treatment. Another producer in Hamilton County is testing this using the corn product he grows-using 1 qt of corn sugar (high fructose corn syrup) per 10 gal of water applied still at V7-v8.
In 2012, a small plot study was conducted at UNL’s South Central Ag Lab near Clay Center to determine any differences between sugar application, fungicide application, and untreated check in corn. All treatments were applied at R2. Because of the drought in 2012, there was minimal disease pressure, thus there were no significant differences between the three treatments regarding area under the disease progress curve. The untreated check did show the most stalk rot (via the push lodging test). The sugar application reduced the lodging rating by half and the fungicide application showed the lowest lodging rating. For yield, there were no significant yield differences with the untreated check yielding the highest followed by the fungicide and sugar applications. The entire study report can be found here.
In Soybeans we have had producers apply 3 lbs sugar in 10 gallons of water at R3 (beginning pod). In all years, there have been no significant differences in yield. Lodging ratings were not taken as that is more variety and water dependent.
has shown that application of sugar to crops increases the numbers of beneficial insects in those fields. South Dakota research entomologists showed that lady beetles benefited from a combination of prey and non-prey foods. In a follow-up study, these entomologists applied sugar sprays to soybeans and quantified the frequency of sugar feeding by analyzing the gut contents of common lady beetles in three states. They found all the tested lady beetles regularly consumed sugar-like nectar in soybean fields, even when it wasn’t applied as a supplement. They also found more lady beetles in the sugar treated plots compared to the untreated plots.
At this time we can’t explain the standability effect we’re seeing from our sugar applications to corn. Our hypothesis is that early application of sugar to corn is increasing beneficial microbes that may be keeping the exposed brace roots and stalks healthier. We hope to conduct more research in the future to answer this question.
the application of sugar to corn and soybeans has not always shown increased yield. However, in nearly all of the corn studies, sugar treated plots have shown increased stalk strength at harvest. Research has also shown an increase in the number of beneficial insects in fields where sugar was applied. Further research is needed to understand the interactions aiding stalk strength in corn.
If you are interested in conducting on-farm research studies in your field, please contact any of our UNL Extension Educators or Specialists! You can also follow the conversations this year via our Facebook page and Twitter feed!