[Fhb-update_ma] FHB Update from MD, 04/28/11
FHB Updates - Mid Atlantic SWW Region
fhb-update_ma at scabusa.org
Thu Apr 28 14:08:20 PDT 2011
Wheat is beginning to head in some parts of Maryland. Flowering is estimated to begin as early as 250 to 300 degree days (base 32F) after the heads start splitting the boot. Depending on the temperatures that can be anywhere from 1 to 2 weeks. Once the heads are fully out flowering can begin in a day or two when warm or up to 5 days later if cool. Flowering for these earlier developing fields is expected to begin sometime next week.
Current scab risk is relatively low. The model is predicting that spore development is only now beginning to get into gear due to favorable conditions in the last 3 to 4 days. But most of the past serious scab epidemics were preceded by longer periods of favorable conditions. It is advisable to keep an eye on this website for any changes to the risk level as your crop approaches flowering.
Fungicide use for scab management is not recommended at this time. Remember, the recommended products, Prosaro and Caramba, will not suppress scab if applied before heading. The best performance of these products is achieved when they are applied at the beginning of flowering. Recent research indicates that applications up to 5 days after flowering may still be able to suppress scab development. However, applications are generally less effective after infection becomes established so it is critical to make the application as close to flowering as possible. There is also a 30 day pre-harvest restriction.
--Arv Grybauskas, Extension Plant Pathologist, University of Maryland
For more details, go to the FHB Risk Assessment Tool at http://www.wheatscab.psu.edu/riskTool_2011.html
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