Tag: risk

Fusarium Head Blight Risk: June 1, 2020

Nidhi Rawat, Small Grains Pathologist
University of Maryland, College Park

Fusarium head blight risk to susceptible wheat as of June 1, 2020. Visit www.wheatscab.psu.edu

Flowering is all finished across all counties of Maryland now, except for a few late planted fields in the northern part of MD that may still be flowering. Currently the risk of FHB is high in these areas and so FHB fungicides (Prosaro, Miravis Ace, Caramba) should be applied here. For most parts, wheat is now in the grain filling stage and should be ready for harvesting in the next couple of weeks. We experienced some showers this season, but the temperatures remained low, so symptom development in terms of bleached spikelets will be limited. It is advisable to get the DON content of the harvested grain analyzed before taking it to the market.

This is the last FHB risk commentary of the season, but feel free to contact me (email: nidhirwt@umd.edu) if you have any questions related to wheat diseases any time of the year!

Fusarium Head Blight Risk: May 19, 2020

Nidhi Rawat, Small Grains Pathologist
University of Maryland, College Park

Screenshot of FHB risk as of May 19, 2020. Risk is low across the state
Fusarium head blight risk to susceptible wheat varieties as of May 19, 2020. Image from: wheatscab.psu.edu.

Wheat in the Eastern shore and the Southern part of Western shore of Maryland has finished flowering, except for a few late planted fields. Up in the North-western counties of the state (Frederick, Howard, Carroll, Harford) wheat is flowering currently. Past week’s low temperatures slowed the progress of wheat. Heads emerged but waited for a week or so to flower in several places. The FHB risk for Maryland does not show to be high currently. However, the unusual pattern of weather has caused several other foliar diseases to appear across the state. Fungal diseases such as Stagonospora nodorum blotch, Stagonospora tritici blotch, Tan spot, Powdery mildew and even some viral diseases such as Wheat streak mosaic virus and Soil-borne mosaic virus have been observed in wheat fields this year. It is important to remember that Strobulurin containing fungicides should not be applied at this stage. Fungicides will not be effective against any viral diseases. However, the FHB fungicides (Prosaro/ Caramba/ Miravis Ace) will be able to control the other fungal foliar diseases. These fungicides do not need to be tank mixed with another product for spraying. The fungicide products should be applied at the full rate recommended by the manufacturers. Aerial application at a rate of 5 gallons per acre or ground application at 15 gallons per acre with 300-350 um droplet size is recommended. Spray nozzles should be angled at 30°-45° down from horizontal, toward the grain heads, using forward- and backward mounted nozzles or nozzles with a two directional spray, such as Twinjet nozzles.

Fusarium Head Blight Risk: May 10, 2020

Nidhi Rawat, Small Grains Pathologist
University of Maryland, College Park

Fusarium head blight risk to susceptible wheat varieties as of May 10, 2020.

Wheat in the Eastern Shore of Maryland and Southern Maryland on the west of shore is finishing up flowering. Wheat in the Northern parts is either flowering/ will soon start flowering. The FHB risk for this part of the state (Frederick, Carroll and Harford counties) is predicted to be moderate to high, especially if the wheat variety planted is susceptible. If the planted variety is resistant, the risk is not predicted to be particularly high. The recommended stage for application of fungicides on wheat is at flowering (50% of the main tillers showing yellow anthers) or within 4-5 days of that. The fungicides effective for FHB are Prosaro/ Caramba/ Miravis Ace. These fungicides do not need to be tank mixed with another product for spraying. The fungicide products should be applied at the full rate recommended by the manufacturers. Strobilurin containing fungicides should not be sprayed at this stage. Aerial application at a rate of 5 gallons per acre or ground application at 15 gallons per acre with 300-350 um droplet size is recommended. Spray nozzles should be angled at 30°- 45° down from horizontal, toward the grain heads, using forward- and backward mounted nozzles or nozzles with a two directional spray, such as Twinjet nozzles.

Fusarium Head Blight Risk: April 26, 2020

Dr. Nidhi Rawat, Small Grains Pathologist
University of Maryland, College Park

Wheat in the Eastern Shore of Maryland has started booting and should be heading out soon. Barley is already flowering there. Note that barley does not show any yellow anthers at flowering and is prone to FHB as soon as it heads out of the boots. Wheat is considered to be at flowering when at least 50% of the heads of a field are beginning to show yellow anthers. With the recent rains FHB risk has increased to moderate/high level in the lower eastern shore counties. Growers here should keep an eye on the FHB risk in the coming days, as wheat heads and flowers here in coming weeks. Fungicides Prosaro, Caramba and Miravis-Ace should be effective in minimizing damage due to FHB in wheat, when applied at flowering. Strobilurin containing fungicides should not be applied now, as they might increase the chances of DON content in the grains. So far, no major concern from other diseases like powdery mildew or rusts has been seen in wheat in the state. Some low intensity incidences of tan spot were observed, which the FHB fungicides applied at flowering should be able to tackle. Up in the northern part of the state wheat is at second node to flag leaf stage, predictably around 2-3 weeks away from flowering.

FHB map of Maryland showing low to moderate risk of head scab
Figure 1. Fusarium head blight risk to susceptible wheat varieties on April 26, 2020.

 Let me know if you have any questions or concerns (nidhirwt@umd.edu).

FHB Update: May 3, 2019

Current risk for Fusarium Head Blight development on susceptible wheat varieties (eg Shirley) for May 3, 2019.

Wheat in the Eastern Shore of Maryland is beginning to flower or will do so
in a couple of days. With yesterday’s rains, and more showers coming our
way, the risk of Fusarium Head has increased significantly in this part of
the state. Growers with wheat flowering (50% of the main tillers showing
yellow anthers) are advised to spray head scab fungicides (Prosaro/ Caramba/
Miravis-Ace) at early flowering or within 4-5 days of this stage. These
fungicides do not need to be tank mixed with another product for spraying.
The fungicide products should be applied at the full rate recommended by the
manufacturers. Strobilurin containing fungicides should not be sprayed at
this stage. Aerial application at a rate of 5 gallons per acre or ground
application at 15 gallons per acre with 300-350 um droplet size is
recommended. Spray nozzles should be angled at 30°-45° down from
horizontal, toward the grain heads, using forward- and backward mounted
nozzles or nozzles with a two directional spray, such as Twinjet nozzles. Up
in the North wheat is booting, and still roughly around 2 weeks away from
flowering.

–Nidhi Rawat, Small grains Pathologist, University of Maryland

For more details, go to the FHB Risk assessment tool at
http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab
Initiative, go to https://www.scabusa.org