5 Tips To Decide If Corn Needs Fungicide

The use of fungicides in corn has been a hot topic in recent years, pitting some manufacturers that tout the effectiveness of preventive applications vs. many Extension specialists’ concerns. For your grower-customers that did not choose a preventive fungicide application, now is the time of year when they need to decide if a fungicide should be applied, and a Purdue University expert offers five tips to help in the decision-making process.

“Deciding whether to apply a fungicide is not a straightforward question,” says Kiersten Wise, Purdue Extension field crops disease specialist. “There are several things that must be taken into consideration.”

University research from across the Midwest shows consistent yield advantages from a fungicide application occur when there is a significant amount of disease in a field, Wise says. “This is the time to get out there and scout and determine the amount of disease in the field,” she adds. “This will really help you decide if a fungicide application is justified.”

Her top tips on what to look for to determine if fungicide application is needed are:

1. Hybrid susceptibility. Hybrids vary in their susceptibility to foliar disease of corn, and hybrids susceptible to diseases such as gray leaf spot are at a greater risk of disease development than hybrids with moderate or high levels of resistance. “As far as limiting yield potential, gray leaf spot is the main disease we are concerned about,” Wise says. “However, if you see a little bit of gray leaf spot in the field when scouting, that doesn’t necessarily mean you need a fungicide application.”

2. Level of disease in the field. Growers should look through the entire field, consider the type of field and where the lesions are located on the plant. “Check to see if lesions are on the ear leaf or if the disease is on a few leaves below the ear leaf and determine the percentage of plants affected,” she says. “Fungicide application should be considered on fields where the hybrid is rated as susceptible or moderately susceptible and 50 percent or more of the plants display disease lesions on the third leaf below the ear and higher prior to tasseling.”

So far, Wise says she has seen gray leaf spot on lower leaves in some susceptible hybrids.

3. Previous crop and cropping system. When looking at the previous crop and cropping system, it’s important to remember that most fungal diseases, such as gray leaf spot, survive from year to year on crop residue. “Planting continuous corn or planting corn into high levels of corn residue with no-till will increase the likelihood for a disease to develop,” Wise says.

4. Late planting and if weather conditions are favorable for disease development. Late planting across much of Indiana, Illinois, and Ohio this spring means the crop is at increased risk of gray leaf spot development, according to research from Iowa State University. Favorable weather conditions for disease development of gray leaf spot are high humidity and moisture levels, as well as moderate to warm temperatures.

5. Pencil it out. Wise cautions growers to be careful in making the decision about whether to apply a fungicide and also include economics in the list of things to consider. “It’s an added cost, and with the price of corn right now, we need to make sure that the fungicide application will pay for itself,” she says.

Economic return depends on fungicide application costs, drying costs, and the price of corn. Wise says an increase of approximately 10 bushels per acre is needed to pay for the cost of fungicide application with corn priced at $3 per bushel and an application cost of about $30 per acre. As the price of corn increases, the additional amount of yield needed to pay for the fungicide application decreases.

So when corn is at $3.50 per bushel and application costs $30 per acre, a yield increase of about 8.5 bushels per acre is needed to pay for the cost of application. If corn reaches $4 per bushel, then a yield increase of about 7.5 bushels per acre is needed to cover application costs.

(Source: Purdue University)

Leave a Reply

Fungicides Stories

FungicidesSudden Death Syndrome, Brown Stem Rot Reported In Indiana Soybeans
September 3, 2014
Farmers and retailers should be watching for symptoms of these two diseases over the next few weeks as they are best managed through preventative methods. Read More
FungicidesResearchers Target Soybean Disease With Genetic Resistance Study
August 6, 2014
University of Illinois researchers will share new information on controlling sudden death syndrome through genetic resistance at this year's Agronomy Day. Read More
Soybean field
FungicidesValent Launches New Seed Protection Fungicide For Soybeans
July 16, 2014
The INTEGO SUITE System contains the first new, novel seed protection fungicide chemistry registered in 30 years by the EPA for protection against Pythium and Phytophthora. Read More
FungicidesNew Players May Make Pest Headlines In Corn, Soybean
April 1, 2014
The usual insects and diseases took a bit of a break in 2013, but other culprits surfaced — and could return. Read More

Trending Articles

Equipment2014 Product Of The Year Voting
September 19, 2014
Many new products were introduced to the ag retail marketplace this year. From this group, CropLife IRON and its consulting partners have selected five finalists for the Product of the Year award. Please cast your vote today to help us determine the winner. Read More
FertilizerFall Fertility 2014: Forecasting Fertilizer Use
September 7, 2014
Great crops this year have tapped the soil, and fall work is definitely called for, but how challenging will that get? Read More
CropLife 100CHS To Build $3 Billion Fertilizer Plant In North Dakota
September 5, 2014
The fertilizer plant in Spiritwood will be the single largest investment in CHS history, as well as the single largest private investment project ever undertaken in North Dakota. Read More
EquipmentNew Holland Acquires Miller-St. Nazianz
September 3, 2014
The assets of Miller acquired as part of the transaction will become part of New Holland Agriculture, a CNH Industrial brand, building on a successful four-year partnership between the two companies. Read More
CropLife 100Pinnacle Acquires East Kansas Chemical
September 2, 2014
Ranked 82nd on the CropLife 100, East Kansas Chemical will operate as part of Pinnacle's Performance Agriculture brand. Read More
MAGIE 2014 ShowStopper
EquipmentJohn Deere Again Wins MAGIE ShowStopper Award
August 25, 2014
For the second consecutive year, John Deere was honored at the Midwest AG Industries Exposition (MAGIE) for its new R4045 sprayer. Read More

Latest News

FertilizerFertilizer Outlook And Technology Conference Set For No…
September 30, 2014
Conference participants can expect to gain perspective on the outlook for agriculture and major fertilizer materials and inputs from industry experts. Read More
MicronutrientsVerdesian Acquires Micronutrient Supplier
September 30, 2014
Verdesian Life Sciences has acquired QC Corp., a producer and supplier of granular and dry micronutrients and ferrous sulfate products. Read More
Eric SfiligojHearing From Young Ag Voices
September 30, 2014
Potential future leaders in ag retail had the chance to shine at the recent Mid America CropLife Association meeting. Read More
WebinarsUpcoming Webinars
September 30, 2014
Register for one of our upcoming Webinars or access our archive of past Webinars to view recordings of presentations that may be of interest to you. Read More
Crop InputsSyngenta Appoints New Chief Operating Officer
September 29, 2014
Jon Parr will succeed retiring COO John Atkin at the end of the year. Read More
CropLife 100South Dakota Wheat Growers To Add Grain-Agronomy Facili…
September 26, 2014
Planned to be constructed in Kennebec, the facility will be located along the soon-to-be rehabilitated line of heavy-rail service from Chamberlain to Presho. Read More
CropLife 100GROWMARK Announces Vice President Appointments
September 25, 2014
Two individuals have been appointed Vice President positions on the GROWMARK executive team. Read More
FertilizerFertilizer Industry Organizations Join Global Alliance …
September 25, 2014
The Fertilizer Institute, the International Plant Nutrition Institute and the International Fertilizer Industry Association are encouraging the industry to promote the proper use of fertilizer products to minimize their environmental impact. Read More
Precision AgARA Organized Precision Forum Hits Capitol Hill
September 24, 2014
The Coalition for the Advancement of Precision Agriculture (CAPA) hosted its inaugural Precision Ag Forum, Sept. 18, in Washington, D.C. Read More
FertilizerFactors To Consider When Placing Fertilizer With Seed
September 24, 2014
The type of crop, fertilizer source, row spacing and soil environment all affect how much fertilizer can be safely applied with seed. Read More
FertilizerSidedressing Manure Into Corn Has Promising Results
September 24, 2014
Applying manure to growing crops can boost yields, reduce nutrient losses and give livestock producers another window of time to apply manure to farm fields. Read More
FertilizerWhen To Sample Manure For Analysis
September 24, 2014
Because the goal is to collect a sample that represents the manure actually being applied, the best time to sample is during loading or field application. Here's why. Read More
Syngenta
Seed/BiotechSyngenta Faces Second Lawsuit Over Agrisure Viptera Cor…
September 23, 2014
A second company has sued Syngenta AG over sales of genetically modified corn seed not approved by China. Read More
StewardshipCover Crops Field Guide For Farmers Expanded
September 23, 2014
Farmers interested in planting cover crops to improve soil health now have an updated and expanded resource in the second edition of the Midwest Cover Crops Field Guide. Read More
HerbicidesArysta LifeScience Launches Contest For Wheat Growers
September 23, 2014
The Flush after Flush Photo Finish contest encourages farmers across the U.S. to participate through Instagram or Twitter using the hashtag #FlushAfterFlush. Read More
FertilizerCF Industries Confirms Merger Of Equals Discussions Wit…
September 23, 2014
CF Industries Holdings, Inc. has confirmed that it is in preliminary discussions with Yara International regarding a potential merger of equals transaction. Read More
StewardshipProgram To Examine Ag-Related Practices, Policies To Pr…
September 22, 2014
A panel discussion on October 14 will include a significant discussion on key issues and solutions related to all aspects of harmful algal blooms. Read More
Eric SfiligojIt’s Product Of The Year Voting Season
September 22, 2014
Readers of CropLife IRON will choose 2014’s best new product over the next month. Read More