New Information:
Animated Maps
Animated maps that show the progress of this disease through the main hazelnut production areas of the Pacific Northwest from 1958 to 2005 have been developed. A survey map shows the location of infected orchards or nursery stock as they were actually discovered while a biology map shows the same information but modified to when we think infection occurred. You may need to download the newest version of "flash player" and then restart your browser to get the animation to work correctly. Just follow the link on the animated maps page. ANIMATED MAPS
Orbit and Tilt
Orbit and Tilt (propiconazole) have received a registration for use on hazelnuts for the control of eastern filbert blight (EFB) spring 2007. Ground or air applications at 5 to 8 fl oz product per acre are legal. Use every 14 days for a maximum of 4 applications (32 fl oz/A/season) and the last one must not be within 60 days of harvest. Orbit has a 24 hr reentry while Tilt has a 12 hr reentry. The following link has our information on this chemical. ORBIT/TILT
When is Bud Break?
(or when do I begin spraying?)
Fungicide applications to control eastern filbert blight are supposed to start at bud break. The fungus is able to infect the immature green portions of the shoot. After bud scales begin to separate and leaf tips become visible, spores of the fungus can gain access to the immature shoot. But not all buds break and begin to grow at the same time. Some are a few days ahead of the majority and some are a few days behind. Count 100 buds and when 50 or more show green leaf or shoot tissue it can be considered bud break.The weather must also be considered when making a spray application decision. Fungicide applications should be made when we have dry calm weather. The fungus is active during long wet periods. If only 40 buds have broken but its about to rain for the next several days you might miss a good spray opportunity. It would be better to spray too early than to spray too late.
Bud Swelling - Buds scales lengthen and turn
green but leaf tissue not quite visible yet.
Photo by Jay W. Pscheidt, 1990.
Bud Break - Green leaf tips begin to poke out of
swollen green buds.
Photo by Jay W. Pscheidt, 1990.
Advanced Bud Break - New leaves small, not
unfolded but easily seen. Highly susceptible to the Eastern Filbert Blight
fungus.
Photo by Jay W. Pscheidt, 1990.
Early Shoot Growth - First leaves are fully open
and shoots begin to get longer. Tip of shoot points down in a
characteristic manner. Shoot tip still susceptible to Eastern Filbert
Blight fungus.
Photo by Jay W. Pscheidt, 1990.
For more information
contact
OSU Faculty.