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

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
Frog eye leaf spot on soybean
FungicidesMake The Case For Fungicides In 2014
February 3, 2014
New products are looking good, but will growers bite with lower crop prices? Read More
FungicidesMANA Introduces Custodia Premix Fungicide For Row Crops
January 14, 2014
New fungicide for corn, soybeans, and wheat contains the two most complementary systemic active ingredients available today in an optimized ratio to deliver both preventive and curative disease control. Read More

Trending Articles

Green Valley Ag facility
Retail FacilitiesGreen Valley Ag Adopts A.J. Sackett’s Precision Fertilizer Blending® Technology At New Facility
July 8, 2014
Sackett's Precision Fertilizer Blending® Technology is making huge strides around the world. Green Valley Ag adopts the technology at its new facility to support its advancing agronomic needs. Read More
Retail FacilitiesWaconia Manufacturing Builds Facility Designed For Speed, Efficiency
July 7, 2014
To make its new hub facility more efficient, Cooperative Elevator enlisted the aid of Waconia Manufacturing. Read More
EquipmentSummer Show Preview 2014: Superior Sprayers Take The Field
July 3, 2014
In this final installment of our coverage of the major categories of Big IRON that retailers can expect to test-drive at this summer’s events, here is a look at 19 sprayers. Read More
Scouting a soybean patch at Green Valley Ag.
EmployeesCropLife Compensation Survey: Battling Talent Drain
July 2, 2014
Retailers too often lose employees to companies outside of agriculture, while recruiting efforts are most often limited to competitors and other ag-focused organizations. Read More
HerbicidesDow AgroSciences Introduces SureStart II Herbicide
June 16, 2014
The enhanced formulation has improved viscosity and increased stability under heat and controls more than 60 high-anxiety grasses and broadleaf weeds found in corn fields. Read More
HerbicidesBASF Investing $270 Million To Expand U.S. Herbicide Production
June 11, 2014
BASF has invested more than $270 million to expand herbicide production capacities in the U.S., including more than 20 new products to be launched over next two years. Read More

Latest News

StewardshipMonsanto Joins Panel Of Innovators To Advance Research …
July 30, 2014
Monsanto Co. and The Climate Corp., its division, recently joined a roundtable of experts at the White House to share ideas and research approaches to help the world’s farmers manage and adapt to the impact of climate change on the global food supply. Read More
Crop InputsSoybean Checkoff Produces Big ROI
July 30, 2014
Under the soy checkoff program, all U.S. soybean farmers contribute a small percentage of their gross soybean sales for research and marketing projects that maximize their profit potential. Read More
CropLife 100Learfield Sports, CHS Agree To Football-Centric, Colleg…
July 30, 2014
CHS Inc. will embark on a highly integrated collegiate sports sponsorship platform with 24 Division I universities in 19 states designed to reach the farmer-owned cooperative's rural owners and customers. Read More
LegislationUSDA Implements Key Farm Bill Crop Insurance Provision
July 30, 2014
The new Supplemental Coverage Option, available through the federal crop insurance program and set to begin with the 2015 crop year, is designed to help protect producers from yield and market volatility. Read More
CropLife 100Wilbur-Ellis Forms New Organizational Structure For Its…
July 30, 2014
The new structure will provide more responsive internal support and will allow regional vice presidents and area managers to spend more time with customers, on talent development and on operational excellence across branches. Read More
Palmer pigweed in cotton
HerbicidesNew Training Modules On Herbicide Resistance Now Availa…
July 30, 2014
The Weed Science Society of America has announced the availability of three new education modules on herbicide resistance in weeds. Read More
HerbicidesWillowood To Market Glufosinate
July 28, 2014
Willowood USA recently announced that Federal EPA has approved its technical registration for glufosinate. Read More
InsecticidesHow To Scout For Corn Earworms In Corn
July 28, 2014
In her weekly report, University of Missouri Agronomy Specialist Jill Scheidt discusses what to look for when scouting for corn earworm. Read More
Crop InputsDuPont Pioneer, Weyerhaeuser Enter Technology License A…
July 28, 2014
The agreement brings together agricultural and forestry know-how to sustainably improve crop productivity for corn growers around the world. Read More
EquipmentAGCO Launches Global iPad App
July 28, 2014
The free AGCO Global iPad App can be downloaded from the Apple iTunes Store and features the full family of RoGator self-propelled sprayers and TerraGator high-floatation spreaders. Read More
Eric SfiligojYuma Centennial Ag Supply Earns 2014 National Environme…
July 28, 2014
Colorado-based ag retailer receives top trophy in 24th annual DuPont Crop Protection/CropLife ceremony. Read More
CropLife 100Pinnacle Forms Alliance With Wildlife Managment, Seed O…
July 25, 2014
The strategic alliance will provide Tecomate with key wildlife products, processing facilities, distribution centers and sales through Pinnacle’s ever-growing retail network. Read More
ManagementFranken Presses White House On RFS Support
July 25, 2014
Al Franken and a group of Senate democrats recently met with senior White House official John Podesta to urge the administration to change its position on an EPA proposal. Read More
ManagementASA, FarmLink To Launch ‘Operation Benchmark̵…
July 25, 2014
The American Soybean Association (ASA) and FarmLink are teaming up to help farmers close the $11 billion gap between what they harvested in 2013 and what they could harvest annually. Read More
StewardshipNorthey: Farmers Commit $1.4 Million to Try New Water Q…
July 25, 2014
The practices that are eligible for funding include cover crops, no-till or strip till and using a nitrification inhibitor when applying fall fertilizer. Read More
Precision AgFarmers Learn How Changing World Will Impact Iowa
July 24, 2014
Technology and understanding global consumer demand for Iowa farm products brought hundreds of farmers and agribusiness leaders to Ames recently for the annual Iowa Farm Bureau Federation Economic Summit. Read More
HerbicidesPurdue: Late Season Weeds May Require Manual Removal
July 24, 2014
Hand-rouging and pulling late season weeds by hand may be the best way to remove them, more so than using a herbicide, a Purdue Extension weed scientist says. Read More
Soybean Field
InsecticidesTransform WG, Closer SC Insecticides Receive R&D 10…
July 23, 2014
Dow AgroSciences has received the award from R&D Magazine for Transform WG insecticide and Closer SC insecticide with Isoclast active. Read More