More than 25 years ago, Fred Below witnessed 300-bushel corn and that motivated him to research the specific factors that affect crop yield. A professor of Plant Physiology in the Department of Crop Sciences at the University of Illinois, Dr. Below recently launched a new website that makes his findings readily available at www.7WondersOfCorn.com.
Each management practice has been categorized into a “wonder.” The higher up on the list, the more control that factor exerts over the Wonders that follow, Below explains in a recent Hoard’s Dairyman article. When combined, Below says all of these factors contribute to big-yield gains:
On the new 7WondersOfCorn.com website, Dr. Below narrates video segments dedicated to each Wonder. The “News” section provides updates on Below’s real-world plots at the upcoming Farm Progress Show in Decatur, Ill. In addition, there is a 7WondersOfCorn Facebook page where growers can share their own photos and experiences.
Goss’s Wilt, which has plagued Nebraska corn fields since 1969, has been spotted in Iowa this season. Iowa farmers are searching for ways to protect yield potential yet this season, as well as avoid the problem in 2012, says ISU Plant Pathologist Alison Robertson.
There are three products that Robertson says she’s heard Iowa corn growers are trying to treat Goss’s Wilt: Procidic, Kocide and Intercept. Procidic is advertised as a broad spectrum fungicide and bactericide. However, Robertson isn’t aware of any published data for the effect of Procidic against bacterial diseases or use on corn. Kocide is not labeled for use on corn to manage Goss’s Wilt, so Robertson said it should not be used. A third product that Iowa growers are reportedly trying is Intercept. There is very little information available on this product, but it’s reportedly been used in Florida to control citrus canker, which is also caused by a bacterium.
Robertson is monitoring a corn field in Gilbert, Iowa, that had an application of Procidic, as well as an earlier application of Stratego YLD. She says she also will be evaluating fields where Intercept has been applied. At the end of the growing season, ISU researchers will study the effect of both products on Goss’s Wilt disease development and general plant health of the corn.
“Continuous corn production together with minimum tillage practices have in part contributed to the epidemic of Goss’s wilt we are witnessing in 2011,” says Robertson in a recent Wallaces Farmer article. “Other factors include susceptible germplasm and stormy weather.”
To avoid Goss’s Wilt in 2012, farmers should keep recommended management practices in mind. Best practices include growing resistant corn hybrids, using crop rotation and crop residue management.
Some people “paint the town.” At Latham Hi‑Tech Seeds headquarters in Alexander, we’re painting the corn fields!
Research Technician Gary Bennett and I used ½-inch paint brushes to apply nearly 500 earworm larvae to approximately 70 ears each of seven different Latham® hybrids. These hybrids featured various technologies and trait packages, including Agrisure Viptera™ 3111 and Genuity® VT Triple PRO™.
Our research objective is to record the level of corn earworm protection offered by the different hybrid traits and technologies. We’ll be taking field notes to record feeding and crop damage every couple weeks. Watch for photo updates soon!
Farmers across the state are starting to see “tipping back,” where kernels aren’t filling all the way to the end of an ear of corn. In this video report, Latham’s Corn Product Specialist explains why high temperatures for prolonged periods during key corn developmental stages have attributed to the amount of tipping back that’s evident this season.
Stress can result in tipping back, agrees Iowa State University (ISU) Extension Corn Agronomist Roger Elmore. Kernels may not have pollinated in the first place or pollinated kernels may have been aborted around milk stage or blister stage. For more information on what causes tipping back, click here to read a related Wallaces Farmer article. To read how tipping back affected yields in 2010, click here.
Night-time temperatures after silking greatly impact yield. Cool night-time temperatures after silking in 2009 resulted in the highest average statewide corn yield ever recorded in Iowa. On the contrary, warm night-time temperatures contributed to lost yield in 2010.
Symptoms of Goss’ Wilt were reported earlier this growing season in Nebraska and Iowa. With all of the storm damage in these areas, including hail and straight-line winds, it’s no wonder that we’re receiving even more reports now of Goss’ Wilt. Stalk bruising and leaf shredding provide ways for pathogens to enter the corn plant. High night-time temperatures, which we’ve also experienced recently, favor the spread of Goss’ Wilt.
Goss’ Wilt causes large lesions that start on the leave’s margins and eventually encompass the entire leaf. These lesions look very similar to Gray Leaf Spot injury. One simple, but not fool-proof, way to diagnose the difference is that Goss’ will have a waxy appearance due to the different
Note the waxy, shiny appearance to the lesions caused by Goss' Wilt
pathogens that cause the disease. Gray Leaf Spot is caused by a fungus while Goss’ is caused by a bacterium, which means Goss’ Wilt cannot be controlled by a fungicide. Effective control measures include crop rotation, tillage and hybrids that show genetic resistance. Latham’s 2012 lineup has a number of hybrids with excellent disease packages, so keep this in mind as you make your seed decisions in the coming months.
The bacterium responsible for Goss’ Wilt may infect the xylem, or water-conducting tissues of the plant, which results in wilting and death.
Seed selection is most likely going to play an even more important role as Goss’ Wilt becomes more prevalent. Bacterial wilt was first reported in Nebraska more than 40 years ago, and the list of states affected keeps growing. Goss’ Wilt has been identified in Kansas, Colorado, Wyoming, South Dakota and Iowa. The disease has also been confirmed in Illinois and Wisconsin, according to a NebGuide article, “Goss’s Bacterial Wilt and Leaf Blight of Corn,” published by the University of Nebraska—Lincoln Extension.
Peter Bixel, Seed-2-Soil powered by Sci Max Team Leader
The effects of this past’s week heat wave on this fall’s corn yields is a main topic of conversation in the countryside. Farmers are wondering if consecutive days of excessive heat will cut yield. It’s true that stress during pollination and silking may result in shorter ears, increased tip back and fewer kernels per ear – all of which contribute to less yield potential. Sometimes.
Fortunately, the availability of pollen is usually not a problem with modern hybrids for a couple of reasons:
At its peak, a plant produces 500,000 pollen grains per day! There is usually more than enough pollen to go around.
Most pollen shed occurs during the morning when temperatures are cooler and moisture stress less evident.
Breeding efforts have significantly improved the stress-tolerance of today’s hybrids. The time between pollination and silking – also known as the anthesis-silk interval (ASI) – is very short with modern hybrids. This shorter ASI results in few barren plants. In older hybrids, however, silking always followed initial pollen shed by at least several days.
The good news iscurrent soil moisture conditions are excellent throughout much of our territory. Likewise, the crop moisture index shows that all of Iowa sits at the midpoint, “Slightly dry/ Favorably moist.” A good share of our soils have high water holding capacity. As the heat spell continues, the differences in mid-afternoon corn leaf rolling between soils with better moisture holding capacities than others will be evident.
High temperature impacts on corn
This heat wave may have a double impact on the crop. The first is the increase in rolling of corn leaves in response to moisture deficiency. By rule-of-thumb, the yield is diminished by 1 percent for every 12 hours of leaf rolling – except during the week of silking when the yield is cut 1 percent per 4 hours of leaf rolling. Unfortunately, most of our crop will be silking next week. The second impact is less obvious initially.
When soil moisture is sufficient, as it is for the most part this July, the crop doesn’t have a measurable yield response to one day of temperatures between 93 F to 98 F. The fourth consecutive day with a maximum temperature of 93 degrees or above, however, results in a 1 percent yield loss in addition to that computed from the leaf rolling. The fifth day there is an additional 2 percent loss; the sixth day an additional 4 percent loss. Data are not sufficient to make generalizations for a heat wave of more than six days, however, firing of leaves becomes likely and very large yield losses are incurred. Generally a six-day heat wave at silking time is sufficient to assure a yield not to exceed trend (Iowa trend yield is near 174 bushels per acre).
Hopefully, this hot-weather trend will end soon! Everything – plants, people and pets – could use a break.
Last week Latham’s Corn Product Specialist Nick Benson posted a video, urging farmers to walk their fields as Corn Borer infestations were spotted in Northeast Iowa. Today he focuses again on European Corn Borer as infestations have risen well over economic thresholds for many producers in the area. His follow-up video further explains why it’s important to catch these pests before they move down the corn stalk.
Click the video link for tips on how to scout beyond the whorl. Make sure you catch your fields before pests move down the plant and “past the point of no return” for foliar-applied control methods.
With foliar-applied insecticides, growers are able to acheive nearly an 80% kill rate. However, when corn borers burrow into the stalk, foliar applications are no longer affective. Growers are then left to rely merely on careful harvest and season management approaches to fight against stalk lodging, ear drop and repeat infestations.
Post-infestation management procedures for harvest and for next season are also included in today’s video by Nick Benson. For more information on scouting for and managing European Corn Borer, contact Latham’s Corn Product Specialist on Twitter @lathamcornguy or contact us directly at this link.
Latham Corn Product Specialist Nick Benson is seeing above-average pressures of corn borer in his northeast Iowa territory. If your acres aren’t protected by a corn borer trait, Nick advises you to check fields as soon as possible for corn borer larvae and consult with an agronomist about treatment if thresholds are met.
Click the video below for information on how to scout your fields for corn borer.
Female moths have dull, buff colored wings while males have brown colored wings.
Corn Borers damage plants when their “boring” tendencies disrupt the plant tissues and interfere with water and nutrient uptake and transfer. Boring into plants creates a wound providing opportunity for infectious disease to enter the plant. Lastly, corn borers can cause weakened stalk and ear strength leading to lodging or ear drop. It’s important to catch these pests early on in the infestation stages to prevent severe damage to the integrity of your plants.
Late-stage larvae commonly tunnel into the earshank of corn.
Management approaches differ according to generation of corn borer, stage of growth in the corn plants and the cost analysis in your field. Iowa State provides these guidelines, but it’s advisable to run an individual analysis and consult with your agronomist for recommendations to suit your unique situation.
For more information on corn borer or management approaches, don’t hesitate to ask questions in the comment box below, or contact us directly.
Nick Benson, Latham’s corn product specialist for the east, has been seeing Twisted Whorl Syndrome in fields.
Corn plant with signs of Twisted Whorl Syndrome
This syndrome is most evident in the late V5 to early V6 stages, when corn has five to six visible leaf collars and is about knee-high. The lowermost leaves appear normal although some may exhibit some crinkled tissue near the base of the leaf blade, according to a newsletter article by Purdue University. Beginning with the sixth or seventh leaf, the whorl is tightly wrapped and bent over at right angles to the ground.
While the cause of Twisted Whorl Syndrome is not fully understood, there are some correlations between weather. This phenomenon is more often
Ribbing on lower leaf results from Twisted Whorl Syndrome.
present when there has been a sharp transition from periods of slow corn development (typically, cool cloudy weather) to periods of rapid corn development (typically, warm sunny weather plus ample moisture).
There is little or no effect on yield from periods of twisted growth. By the time the affected plants reach waist to chest-high, the only evidence that remains of the previous twisted whorls is the crinkled appearance of the most-affected leaves.
Click the video link below for a short “How To” from Nick Benson on identifying Twisted Whorl Syndrome in your fields.
What a difference one week makes! A weekly survey shows 69% of Iowa’s 2011 corn crop was planted as of May 8 compared to only 8% on May 1.
Yesterday, while being interviewed as part of Latham’s Crop Tour, Latham® dealer Mike Aldinger said he finally started planting his corn on Monday, May 2. He finished planting the last of his corn acres Monday, May 9, on his farm near Iowa Falls, Iowa, in the North Central part of this state.
Without delay, Mike started planting his 2011 soybean crop. Going straight from planting corn to soybeans appears to be the trend this season, but it has caused many farmers to question whether it’s the right thing to do. Optimal soil temperatures for soybean germination and growth is a minimum of 55-60 degrees Fahrenheit, and soil temperatures statewide are averaging well above that this week.
“Last year many soybeans were planted in mid-to-late April in absolutely perfect soil and weather conditions. Then cold, rainy conditions followed,” John Holmes, Iowa State University Extension crop specialist at Clarion in north central Iowa, was quoted in yesterday’s Wallaces Farmer article.
That’s why it’s important for farmers to take a look not only at current weather conditions but also at the short-term forecast. If the seedbed is suitable, we’re encouraging our customers to start planting soybeans without delay.
Soil temperatures have climbed an average of 1 degree daily for the past three days in a row in Franklin County, Iowa. And, soil temperatures should only continue to climb thanks to 90-degree temps yesterday and highs in the 80s and 70s forecast for the next two days. The five-day forecast calls for temperatures to cool slightly and for rain to set in late this week, so it appears there is a window of opportunity to plant soybeans now. Why not take it?
More than 25 years ago, Fred Below witnessed 300-bushel corn and that motivated him to research the specific factors that affect crop yield. A professor of Plant Physiology in the Department of Crop Sciences at the University of Illinois, Dr. Below recently launched a new website that makes his findings readily available at www.7WondersOfCorn.com.
