To Control Head Scab In Barley

On May 06, 2019

To Control Head Scab In Barley

A cold fall and overcast and wetter than average spring have kept small grains short in many areas, but that hasn’t stopped crop development.  Some barley varieties have headed in the southern parts of PA, and others are not far behind.   Extension Plant Pathologist Alyssa Collins reports the environment has been generally unfavorable for the development of many of the fungal diseases we usually deal with during the Spring.  

Nonetheless, now is the critical time to prepare to control Fusarium head blight (FHB) also called head scab.  If you intend to protect your barley from scab be prepared to spray a fungicide at 50% heading or shortly thereafter.  As many of you know, this is a disease of wheat and barley that can lead to the production of vomitoxin (DON) in grains.  

Once your crop begins heading, there is about a 5-to-6 day window to apply a fungicide. The labels state the last stage of application is mid-flower and there is a 30-day to harvest restriction.  Do not use any of the strobilurins (Quadris, Headline), or strobilurin/triazole (Twinline, Quilt, Stratego) combination products at flowering or later. There is evidence that they may cause an increase in mycotoxin production. 

At this point in the season, the only way to reduce the scab problem is to spray. But in general, do not rely solely on fungicides, as they will provide at most a 50–60% reduction in scab severity and vomitoxin. Start with selecting resistant varieties, and time sprays properly to achieve greater control.

A new fungicide, Miravis Ace, has been labeled for the control of head scab in barley and wheat, and university trials have found it to provide disease suppression similar to existing products, but using a different chemistry.    Caramba or Prosaro are our traditional scab products and, along with Miravis Ace, give good control of most leaf and head diseases, in addition to suppressing scab. They do not need to be tank mixed with another product to control these diseases.  Spray nozzles should be angled at 30° down from horizontal, toward the grain heads, using forward- and backward mounted nozzles or nozzles with a two directional spray, such as Twinjet nozzles.  

As our season progresses, keeping an eye on the FHB Risk Assessment Tool will become critical for those farmers who are trying to make the decision to spray small grains or not.  This forecasting site,, is an online model that helps us predict infection risk levels everywhere in the state. It works best in the Mozilla Firefox browser and updates each day around 10am.  Visit it at your convenience or sign up to have updates e-mailed or texted directly to you. 

To Learn About Shitake Mushroom Production

The Shiitake Mushroom School will be held at Penn State Extension Lehigh County, 4184 Dorney Park Road, Allentown, on May 14 from 6 to 9 p.m.

This hands-on school will cover the primary information needed to grow Shiitake mushrooms on natural logs. Topics include Mushroom 101, Tree Selection, Log Inoculation, Stacking/Fruiting and Marketing/Business Planning.

The instructors and organizers of this program are John Pecchia, Penn State University; Maria Gorgo-Gourovitch, John Wodehouse, Megan Chawner and Christi Graver from Penn State Extension.

Each participant will get to take home one inoculated log. Please bring a pair of outdoor work gloves for use during the hands-on process.

The cost to attend is $85 and includes all materials needed.

To register, visit or call Penn State Extension Customer Service Team at 1-877-345-0691.

To Monitor Black Cutworm Moths 

The black cutworm is a cosmopolitan pest that poses an economic threat to many agricultural plant species. In Pennsylvania field crops, it is most often a pest of corn, but can also cause trouble in wheat and tobacco. It will also attack some vegetable crops, including sweet corn, and can be problematic in turf grasses. While black cutworm has the potential to be a very serious pest, it is sporadic with major outbreaks being relatively rare (1980 was a particularly bad year in Pennsylvania with at least 5,000 acres of corn being decimated). Nevertheless, it warrants attention because losses can be severe if it infests fields at the right time.

Again this year Penn State Extension and the Department of Entomology are monitoring black cutworm populations with pheromone traps. Extension Entomologist John Tooker reports as moths arrive, if we capture eight or more moths over the course of two nights (a “significant flight”), there is an elevated risk in that particular area of cutting damage by caterpillars later in the spring. Early last week, we detected a significant flight of moth in Potter County (near Ulysses). In other parts of the state, thus far we have detected low numbers of moths, and none that have exceed eight moths over two nights. We continue to trap for others but will now begin degree-day accumulations to predict the timing of cutting for Potter County to inform folks when they should be scouting fields for damage. 

The degree-day accumulations for Potter County is around 20 and cutting damage tends to occur once we reach 300 degree days, so the time to scout has yet to arrive. When you do scout your fields, note that black cutworm caterpillars can damage corn from first emergence up to V4 or V5. For young plants, cutworm damage can look like a series of symmetrical holes through the leaves. Remember that if cutting damage is found, rescue treatments are usually the most efficient and economical tactic for managing black cutworm. For more information see our fact sheet:

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