For the record, "cool" spring to us is in the low 70's, as it is not
unusual to have some 100F+ days in April.  This year we even got a rain and
decent mountain snow after Easter.

Our worst FB weather is cool, foggy mornings burning off to hazy days in
the 80's. The hot days we got last week with low RH were accompanied by
pretty stiff winds, the kind of weather that dries your jeans on the
clothesline really fast.  I never saw scab or powdery mildew until I
visited an orchard in Santa Cruz (ewww, what's that stuff?...).

The Uganda nursery is 80F year-round, glad there's no FB there or there
would be no stopping it.  Plenty of scab and PM though.


On Mon, 22 May 2017 12:45:41 -0400, Daniel Cooley <>
> My guess is that it’s not so much the heat as the humidity, Kevin. I
> when you get as dry as it gets in Riverside on a hot day, it may indeed
> kill off the epiphytic bacteria, and make further transmission
> Today and tomorrow it looks like your dewpoint is 47 to 52 F (8 to 11
> Vincent), and RH dips to nearly 20%!  Perhaps the heat/water stress also
> stops progress in infected tress. 
> Dan
>> On May 22, 2017, at 12:36 PM, Vincent Philion
>> <> wrote:
>> Hi!
>> it would be interesting to define “cool” in the southern California
>> context. ;-)
>> Temperature in the mid-90 (35 ℃ for the rest of the planet) (or more)
>> clearly isn’t favorable for blight. Flowers age faster at that
>> temperature, while the bacteria is slowed down.
>> Plus, if the trees are under water stress the bacteria can’t progress
>> normally.
>> Your “cool” is our “warm” and that’s why we struggle with FB, but also
>> scab and CM.
>> Vincent
>>> Le 22 mai 2017 à 00:29, a écrit :
>>> A long, cool spring here in Southern California allowed quite a few FB
>>> strikes, three days in the low to mid-90's stopped it in its tracks. 
>>> Formerly limp shoots with sticky ooze and now crispy and dry, and
>>> stumps do not get re-infection.  That's all I'll see of it until next
>>> spring, weeks of 100+ weather and 5% humidity sees to that. 
>>> Unfortunately
>>> it doesn't slow down the CM a bit, which is my next nemesis on the
>>> calendar.
>>> Kevin Hauser
>>> Kuffel Creek Apple Nursery
>>> Riverside, California
>>> Nakifuma, Uganda
>>> On Mon, 22 May 2017 02:45:06 +0000 (UTC), lee elliott
>>> <>
>>> wrote:
>>>> For the first year ever I havent seen any FB here is western
>>>> could it be th 86 degree days we had burned it out, I believe FB
>>> out
>>>> after a few hot days, some dont believe this but experience has
>>> me
>>>> it is true, Shoot bligt and root sucker blight has allways been a
>>> problem,
>>>> I am sceptical that these antobiotic sprays work at all, only good
>>> the
>>>> blooms and chemical dealers, Copper does work well on young hursery
>>>> non-bearing trees that get shoot blight where your not woried about
>>> fruit
>>>> finish, My person opiniion, low soil levels of copper, (do a leaf
>>> anayisis)
>>>> make the tree stressed and contribute to FB. Just my 2 cents worth,
>>>> Elliott, Upstart Nursery, Winchester Illinois
>>>> _______________________________________________
>>>> apple-crop mailing list
>>> _______________________________________________
>>> apple-crop mailing list
>> _______________________________________________
>> apple-crop mailing list
> _______________________________________________
> apple-crop mailing list
apple-crop mailing list

Reply via email to