August 23, 2014

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Time for farmers to scout for pests PDF Print E-mail
Wednesday, June 04, 2014 8:34 PM


Putnam County Extension

Ag Educator


This article was written by Ed Lentz and revised and updated by Jim Hoorman.

The wheat crop is generally looking good this year but farmers should start scouting for pests.

The wheat crop will produce no more leaves or tillers by the time the grain heads have emerged from the stems. The existing leaves will have to provide all the photosynthetic energy the plant and grain need until harvest.

One leaf on the wheat stem provides most of the energy for the developing grain. It is the last leaf to emerge and the first leaf below the grain head called the flag leaf since it is the highest of the leaves and resembles a flag. Grain yields will be significantly reduced if pests or nature damages this leaf early in the grain fill period since it provides 80-85 percent of the wheat’s carbohydrates.

To prevent yield losses, farmer may use fungicides to protect the flag leaf against foliar diseases such as septoria and powdery mildew. Farmers will also scout fields to insure that insects are not damaging the flag leaf and use an insecticide if the insect population is above an established threshold level. The most common insect problems are armyworms and cereal leaf beetles.

Many wheat fields are now flowering and the pollination process generally is completed in three to five days. During flowering, the wheat head is susceptible to infection from a serious disease called Fusarium head scab. Infected kernels may produce a toxin called vomitoxin that is harmful to humans and livestock. This same Fusarium fungus also infects corn stalks and becomes the source of Fusarium head scab in wheat. The amount of fungal spores produced is dependent on spring temperatures and spores will not infect wheat heads except during extended periods of rain and high humidity during flowering.

Resistant wheat varieties are the best control against Fusarium head scab. However, these varieties generally yield significantly less than non-resistant varieties. In recent years, fungicides have become available. However, they are expensive, have to be sprayed at flowering to be effective and still only provide about 50 percent control. It can be difficult to apply fungicides if it rains during wheat pollination.

Plant pathologists (including Ohio State University Extension) have developed a computer program that predicts the risk of head scab. Farmers and consultants use this program to determine the need of a fungicide for head scab. The program may be found at At this time the program has shown low risk for head scab across the state of Ohio.

The wheat crop in general looks good in our area with only a few pest problems. Wheat is shorter than normal so straw may be in short supply again this year. If Mother Nature cooperates, a respectable crop should be harvested in about 30 to 40 days. (Lentz, 2014)

Wheat is a cool season grass so if temperatures remain below 80 degrees Fahrenheit, wheat generally produces higher yields. Once the temperature gets above 80, wheat starts to die and the plant produces less carbohydrates and sugars, so the wheat yield goes down.

Sam Custer, Darke County Extension, provided the following information.

Barry Ward, Leader, Production Business Management in the Department of Agricultural, Environmental and Development Economics has announced the release of the 2014 Ohio Field Crop Enterprise Budgets. OSU Enterprise budgets help track farm income and expenses to determine the most profitable enterprise(s) and if you have met your farm goals.

Budgeting is often described as “penciling it out” before making financial decisions and committing resources to a plan. OSU Extension has developed “Enterprise Budgets” for many years as a starting point in the budgeting process. Newly updated 2014 Enterprise budgets are available at New 2014 Enterprise Budgets include: Corn-Conservation Tillage, Soybeans-No-Till (Roundup Ready) and Wheat-Conservation Tillage.

Users can input their own production and prices levels on downloadable Excel spreadsheets to calculate their own numbers. The spreadsheets were easy-to-use macros and color-coded cells that allow producers to plug in their own numbers to calculate their bottom line for different scenarios. Detailed footnotes help explain the methodology behind the budget numbers. Budgets include a date in the upper right hand corner of the front page to indicate when the last update occurred. (Custer, 2014)


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