Apple Pest Report: Monday, May 8, 2006
Vol. 14 No. 4
Scab
The forecast call for an extended rainy period beginning
Tuesday night and lasting into Sunday, May 14. Because of abundant
scab-susceptible young leaf tissue, progressing ascospore maturity, the
duration of the expected wetting, and the accumulation of over 2 inches
rain during this period, this looks to be a serious scab infection event
representing about 40% of the season's total primary scab infection
potential.
Orchards that have not been had fungicide coverage renewed
since Friday, May 5 should receive renewed coverage prior to start of
the rain if possible. The forecast sounds like it might be an
extended period of spotty showers, rather than continuous rain. If
so, and if foliage was not adequately protected going into the rainy
period, it may be possible to make an application during a break in the
rain. One hour of good drying conditions is sufficient for most
contact-surface fungicides (such as captan) to establish residual
protection. A good hour of drying is also long enough for sterol
inhibitor (SI) fungicides and strobilurin fungicides to be absorbed into
leaf tissue.
If neither a preemptive protective application or "break in the rain" application is possible for trees without adequate protection to last through the infection period, then a fungicide with post-infection activity should be applied as soon as possible after the rain stops and leaves are dry enough to retain spray. Fungicides with extended post-infection activity are Nova, Rubigan, Procure (SI group), and Flint, Sovran and Pristine (strobilurin group).
Insects
and Mites
TARNISHED
PLANT BUG activity remains low-moderate at
Highmoor Farm. On traps checked Monday, May 8 at Highmoor Farm,
where McIntosh trees were are full Pink, total accumulations since
Silver Tip in three blocks were 0.75, 1.0, and 2.25 per trap.
Compared to the Pink thresholds of 5 (wholesale) or 8 (retail) TPB per
trap, the population at Highmoor Farm does not require prebloom
insecticide.
Leafminer moths
Leafminer populations remain very low at
Highmoor Farm as of Monday May 8. The cumulative average per trap
in three blocks was 0.25, 0.5, 0.25. These levels are far below
red trunk trap thresholds. But even if they were above threshold,
it would be better to assess the leafminer population by counting the
number of sap-feeding mines a week after McIntosh petal fall.
Apple Pest Thresholds Card
There is a Apple Pest Thresholds card
online you can download to help you keep track of the different pests
and their economic threshold levels. The card is at
Maine apple pest threshold and ID card .
It is a 157K PDF file, so it will take 30-40 seconds to download
with a dial-up modem, and requires the free Adobe PDF reader to view and
print, the reader can be download at
http://www.adobe.com/products/acrobat/readstep2.html
Sincerely,
Glen
Glen Koehler
Pest Management Office
491 College Avenue
Orono, ME 04473
Voice: 207-581-3882
Email:
gkoehler@umext.maine.edu
Web:
PRONewEngland.org
Fax: 207-581-3881
What we call the secret of happiness is no more a secret than our willingness to choose life. - Leo Buscaglia