North American Fruit Explorers mailing list at ibiblio

[<dmnorton@royaloakfarmorchard.com>]

Neil,

Plum curculio become active at a base temperature of 43 degrees F.  So in 
any temp above 43, they can become active.  They are mostly active at night 
and will begin to migrate into trees from overwintering wooded areas at 
about 113 degree days, base 43.  Their migration is almost always based on 
tree phenology, which in turn, is based on degree days.  Therefore, a degree 
day model is best for timing their movement.  In Maryland, they may start to 
migrate a bit earlier, possibly at or just before tight cluster.  Surround 
is only a repellant and you need to make multiple applications starting 
before bloom to achieve complete coverage.  They will remain active in rain, 
especially if they have been overwintering below the soil line. For a 
complete look at PC control and their life cycle based on a degree day model 
for both apples and cherries you can download the PDf at 
http://www.treefruit.msu.edu/extension/CAT/21_14b.pdf which I use for all of 
my PC timing.  Hope this helps.

Dennis Norton
Royal Oak Farm Orchard
Office (815) 648-4467
Mobile (815) 228-2174
Fax (609) 228-2174
http://www.royaloakfarmorchard.com
http://www.theorchardkeeper.blogspot.com
http://www.revivalhymn.com


----- Original Message ----- 
From: "Neil Lewis" <lewisn@georgetown.edu>
To: <nafex@lists.ibiblio.org>
Sent: Sunday, May 03, 2009 8:48 PM
Subject: [NAFEX] plum curculio in cold and wet


> Does anyone know the answers to the following questions regarding plum 
> curculio: (1) Are they active in temperatures under about 60 degrees? (2) 
> Are they active in the rain? I have been using Surround on my fruit trees 
> this year for the first time, but continuous rain here in suburban 
> Maryland has washed most of it off today and rain and temperatures in the 
> high 50s and low 60s are forecast for the next few days. The curculio are 
> definitely about, as they have already scarred some apples and sour 
> cherries.
>
> Neil Lewis
> Beltsville, MD