[Fhb-update_ma] FHB Update from MD, 04/29/16

FHB Updates - Mid Atlantic SWW Region fhb-update_ma at scabusa.org
Fri Apr 29 10:59:17 EDT 2016


Wheat is beginning to head in southern Maryland and appears to be in early
boot on the lower Eastern Shore. The susceptible period to scab is from the
start of flowering through early stages of dough development. The fungicide
application window for scab and for the reduction of the toxins that develop
in scabby grain, is a 5 day period beginning at early flower (50% of the
tillers just beginning to extrude anthers from the head). We are now
experiencing a string of days with scattered rainfall, high humidity and
overcast skies. An extended period of moist conditions prior to the start of
flowering is one key component to scab outbreaks. However, temperatures are
currently too low for extensive fungal development so spore production will
be minimal. Expect to see the risk assessment remain low unless temperatures
increase and frequent showers continue. Continue to monitor this website as
your fields approach flowering to help determine if a fungicide application
is warranted. Note that stripe rust has been found in pockets on the Eastern
shore and has also been reported from Southern Maryland (St. Mary’s
County). Cool moist weather is ideal for stripe rust to increase and spread.
As long as rust infection levels remain low you may be able to hold off
spraying for stripe rust until early flower to get activity against both
diseases. Pre-flower applications of fungicides will have no benefit in the
reduction of scab. It is important to closely examine your fields. There are
many sites with leaves exhibiting yellow stripes and blotches that are not
infected with a fungal disease. Many of these have a viral disease that
cannot be managed with a fungicide.

--Arv Grybauskas, Extension Plant 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 http://www.scabusa.org



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