Re: [apple-crop] spectrum instruments
Hello All,
I have a few Spectrum machines and have seen the discrepancies between the
different models. As someone else mentioned, one of the reasons is probably
related to the issue on how to decide if 2 or more wetting events should be
considered one continuous wetting event. The NEWA (Network for Environment and
Weather Applications), http://newa.cornell.edu site says Two successive
wetting periods are considered a single uninterrupted wetting period if the
intervening dry period is 24 hours. When I compare the NEWA data from an
orchard in CT to nearby orchards with Spectrum machines, the NEWA site has
indicated infections when the Spectrum machines did not.
Do Plant Pathologists agree on how to decide if 2 wetting periods should be
combined?
Thanks,
Lorraine Los
Entomologist and Fruit Crops IPM Coordinator
University of Connecticut
From: apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] On Behalf Of Jon Clements
[jmcext...@gmail.com]
Sent: Sunday, April 24, 2011 7:02 PM
To: Apple-crop discussion list
Subject: {SPAM?} Re: [apple-crop] spectrum instruments
Yea, look at me, given my old(er) age -- the NRVART (Newspaper
Readability Venturia Ascospore Release Threshold) depends on: the
light level (civil twilight, nautical twilight, astronomical twilight?
see: http://en.wikipedia.org/wiki/Twilight) , distance reading the
Newspaper (far is probably better I am farsighted, oh not really,
actually I am presbyoptic,
see:http://en.wikipedia.org/wiki/Presbyopia), font size (obviously),
and whether or not I can find my eye glasses. (Forgetfullness, sorry,
not in Wikipedia, but my bi-focal glasses are no-line TransitionsTM,
CriizalTM no-glare/reflections, about $250 each at Costco or WalMart
if I buy the cheaper frames.) Oh, and does the NRVART include reading
the newspaper on an iPad?
But BTW, I can perfectly relate to the PDBA fireblight index!
Sorry to downgrade an otherwise excellent discussion!
:-)
Jon
On Sun, Apr 24, 2011 at 6:20 PM, Dave Rosenberger da...@cornell.edu wrote:
Hey, Dan --
I believe that the reading a newspaper threshold for ascospore
discharge was a verbal comment from either Gadoury or MacHardy. Given my
failing memory, I can't be absolutely certain that my recollection is
correct. Anyway, this may be one of those rules of thumb that never make
it into the scientific literature, probably for the same reasons that my
personal discomfort model for timing strep sprays for blossom blight will
never make it into a refereed journal. After all, we're concerned about
trying to calibrate leaf wetness meters: Just think about trying to
calibrate humans as biological sensors!!
David,
The original night-time release study was published by MacHardy and
Gadoury in 89. It's here:
http://www.apsnet.org/publications/phytopathology/backissues/Documents/1989Articles/Phyto79n03_304.pdf
In 98, Gadoury, Stensvand and Seem revised this to take into account some
night-time release, saying that in high inoculum orchards night-time release
could be a problem. That article is here:
http://apsjournals.apsnet.org.silk.library.umass.edu/doi/pdfplus/10.1094/PHYTO.1998.88.9.902
I've been looking all over for the source article for Dave Rosenberger's
Newspaper Readability Venturia Ascospore Release Threshold, but haven't
found it. I did, however, find his Personal Discomfort Blight Alert for
blossom blight:
... severe blossom blight infection periods often occur on days when
moderate physical activity causes me to break into a noticeably
uncomfortable sweat. The discomfort comes from a combination of high
temperature, high humidity, and lack of acclimation to summer temperatures.
If I sense PDBA conditions when trees are in bloom, then I know that a
blossom blight spray is needed immediately.
http://www.scaffolds.entomology.cornell.edu/2007/070507.html#disease
Degree days and leaf wetness sensors are interesting and helpful, but
sometimes nothing beats the low-tech approach!
Dan
On Apr 21, 2011, at 11:33 PM, David Doud wrote:
thank you Dave for the time and effort you put into this post -
short of input from specmeters, I'll slightly exaggerate and say that
the Cornell model will predict scab infection after a short heavy dew, while
the WA model requires rainforest conditions for a couple of days before it
indicates concern - I made the assumption that if growing McIntosh in NY one
had better be very careful, while desert conditions don't provide the
humidity or inoculum to result in scab infections except under the most
severe circumstances - I talk to growers at the Ohio River and south and
they don't worry much about scab, it's a minor consideration in their
climate -
the Mills table (and modified Mills - I attended a number of the MI IPM
schools in the '80s when Jones and Howitt and Bird and crew was cutting
edge) has been reliable here and referred to
[apple-crop] RE : spectrum instruments
Hello ms Los.
In a nutshell: pathologists seldom agree on anything.
;-)
More seriously, 24 hrs was suggested by MacHardy based on different sources and
is a OK value.
However, there is field data on potted plants that show SOME ascospore survival
for many days.
That's one of the many reasons why yes/no rules cannot be used for scab
models. Instead, the relative risk of each component should be treated as a
population process with a average and deviation: some spores are quicker, some
are more tolerant, etc.
... that's how RIMpro calculates risk
Vincent
De : apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] de la part de Los, Lorraine
[lorraine@uconn.edu]
Date d'envoi : 26 avril 2011 10:25
À : Apple-crop discussion list
Objet : Re: [apple-crop] spectrum instruments
Hello All,
I have a few Spectrum machines and have seen the discrepancies between the
different models. As someone else mentioned, one of the reasons is probably
related to the issue on how to decide if 2 or more wetting events should be
considered one continuous wetting event. The NEWA (Network for Environment and
Weather Applications), http://newa.cornell.edu site says Two successive
wetting periods are considered a single uninterrupted wetting period if the
intervening dry period is 24 hours. When I compare the NEWA data from an
orchard in CT to nearby orchards with Spectrum machines, the NEWA site has
indicated infections when the Spectrum machines did not.
Do Plant Pathologists agree on how to decide if 2 wetting periods should be
combined?
Thanks,
Lorraine Los
Entomologist and Fruit Crops IPM Coordinator
University of Connecticut
From: apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] On Behalf Of Jon Clements
[jmcext...@gmail.com]
Sent: Sunday, April 24, 2011 7:02 PM
To: Apple-crop discussion list
Subject: {SPAM?} Re: [apple-crop] spectrum instruments
Yea, look at me, given my old(er) age -- the NRVART (Newspaper
Readability Venturia Ascospore Release Threshold) depends on: the
light level (civil twilight, nautical twilight, astronomical twilight?
see: http://en.wikipedia.org/wiki/Twilight) , distance reading the
Newspaper (far is probably better I am farsighted, oh not really,
actually I am presbyoptic,
see:http://en.wikipedia.org/wiki/Presbyopia), font size (obviously),
and whether or not I can find my eye glasses. (Forgetfullness, sorry,
not in Wikipedia, but my bi-focal glasses are no-line TransitionsTM,
CriizalTM no-glare/reflections, about $250 each at Costco or WalMart
if I buy the cheaper frames.) Oh, and does the NRVART include reading
the newspaper on an iPad?
But BTW, I can perfectly relate to the PDBA fireblight index!
Sorry to downgrade an otherwise excellent discussion!
:-)
Jon
On Sun, Apr 24, 2011 at 6:20 PM, Dave Rosenberger da...@cornell.edu wrote:
Hey, Dan --
I believe that the reading a newspaper threshold for ascospore
discharge was a verbal comment from either Gadoury or MacHardy. Given my
failing memory, I can't be absolutely certain that my recollection is
correct. Anyway, this may be one of those rules of thumb that never make
it into the scientific literature, probably for the same reasons that my
personal discomfort model for timing strep sprays for blossom blight will
never make it into a refereed journal. After all, we're concerned about
trying to calibrate leaf wetness meters: Just think about trying to
calibrate humans as biological sensors!!
David,
The original night-time release study was published by MacHardy and
Gadoury in 89. It's here:
http://www.apsnet.org/publications/phytopathology/backissues/Documents/1989Articles/Phyto79n03_304.pdf
In 98, Gadoury, Stensvand and Seem revised this to take into account some
night-time release, saying that in high inoculum orchards night-time release
could be a problem. That article is here:
http://apsjournals.apsnet.org.silk.library.umass.edu/doi/pdfplus/10.1094/PHYTO.1998.88.9.902
I've been looking all over for the source article for Dave Rosenberger's
Newspaper Readability Venturia Ascospore Release Threshold, but haven't
found it. I did, however, find his Personal Discomfort Blight Alert for
blossom blight:
... severe blossom blight infection periods often occur on days when
moderate physical activity causes me to break into a noticeably
uncomfortable sweat. The discomfort comes from a combination of high
temperature, high humidity, and lack of acclimation to summer temperatures.
If I sense PDBA conditions when trees are in bloom, then I know that a
blossom blight spray is needed immediately.
http://www.scaffolds.entomology.cornell.edu/2007/070507.html#disease
Degree days and leaf wetness sensors are interesting and helpful, but
sometimes nothing beats the low-tech approach!
Dan
On Apr 21, 2011, at 11:33 PM, David Doud wrote:
Re: [apple-crop] spectrum instruments
The 24 hour time frame used in NEWA was decided on by Bill Turechek when he was
the extension tree fruit pathologist at Cornell and is primarily based on the
work by Becker and Burr on interrupted wetting events. Prior to that NEWA had
used 8 hours.
The tricky part comes in combining a combined event with another event... when
does one stop combining events. In some cases, if a dew period is counted,
then the infection event could go on and on and on.
Julie
NEWANEWANEWANEWANEWA
Juliet E. Carroll, PhD
Project Leader, NEWA
Network for Environment Weather App's
NYS IPM Program, Cornell University
630 W. North St., Geneva, NY 14456
315-787-2430, j...@cornell.edu
NEWA Pest Forecasts, newa.cornell.edu
-Original Message-
From: apple-crop-boun...@virtualorchard.net
[mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of Vincent Philion
Sent: Tuesday, April 26, 2011 12:11 PM
To: Apple-crop discussion list
Subject: [apple-crop] RE : spectrum instruments
Hello ms Los.
In a nutshell: pathologists seldom agree on anything.
;-)
More seriously, 24 hrs was suggested by MacHardy based on different sources and
is a OK value.
However, there is field data on potted plants that show SOME ascospore survival
for many days.
That's one of the many reasons why yes/no rules cannot be used for scab
models. Instead, the relative risk of each component should be treated as a
population process with a average and deviation: some spores are quicker, some
are more tolerant, etc.
... that's how RIMpro calculates risk
Vincent
De : apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] de la part de Los, Lorraine
[lorraine@uconn.edu] Date d'envoi : 26 avril 2011 10:25 À : Apple-crop
discussion list Objet : Re: [apple-crop] spectrum instruments
Hello All,
I have a few Spectrum machines and have seen the discrepancies between the
different models. As someone else mentioned, one of the reasons is probably
related to the issue on how to decide if 2 or more wetting events should be
considered one continuous wetting event. The NEWA (Network for Environment and
Weather Applications), http://newa.cornell.edu site says Two successive
wetting periods are considered a single uninterrupted wetting period if the
intervening dry period is 24 hours. When I compare the NEWA data from an
orchard in CT to nearby orchards with Spectrum machines, the NEWA site has
indicated infections when the Spectrum machines did not.
Do Plant Pathologists agree on how to decide if 2 wetting periods should be
combined?
Thanks,
Lorraine Los
Entomologist and Fruit Crops IPM Coordinator University of Connecticut
From: apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] On Behalf Of Jon Clements
[jmcext...@gmail.com]
Sent: Sunday, April 24, 2011 7:02 PM
To: Apple-crop discussion list
Subject: {SPAM?} Re: [apple-crop] spectrum instruments
Yea, look at me, given my old(er) age -- the NRVART (Newspaper Readability
Venturia Ascospore Release Threshold) depends on: the light level (civil
twilight, nautical twilight, astronomical twilight?
see: http://en.wikipedia.org/wiki/Twilight) , distance reading the Newspaper
(far is probably better I am farsighted, oh not really, actually I am
presbyoptic, see:http://en.wikipedia.org/wiki/Presbyopia), font size
(obviously), and whether or not I can find my eye glasses. (Forgetfullness,
sorry, not in Wikipedia, but my bi-focal glasses are no-line TransitionsTM,
CriizalTM no-glare/reflections, about $250 each at Costco or WalMart if I buy
the cheaper frames.) Oh, and does the NRVART include reading the newspaper on
an iPad?
But BTW, I can perfectly relate to the PDBA fireblight index!
Sorry to downgrade an otherwise excellent discussion!
:-)
Jon
On Sun, Apr 24, 2011 at 6:20 PM, Dave Rosenberger da...@cornell.edu wrote:
Hey, Dan --
I believe that the reading a newspaper threshold for
ascospore discharge was a verbal comment from either Gadoury or
MacHardy. Given my failing memory, I can't be absolutely certain that
my recollection is correct. Anyway, this may be one of those rules of
thumb that never make it into the scientific literature, probably for
the same reasons that my personal discomfort model for timing strep
sprays for blossom blight will never make it into a refereed journal.
After all, we're concerned about trying to calibrate leaf wetness
meters: Just think about trying to calibrate humans as biological sensors!!
David,
The original night-time release study was published by MacHardy and
Gadoury in 89. It's here:
http://www.apsnet.org/publications/phytopathology/backissues/Document
s/1989Articles/Phyto79n03_304.pdf
In 98, Gadoury, Stensvand and Seem revised this to take into account
some night-time release, saying that in high inoculum orchards
night-time release could be a problem. That
[apple-crop] RE : spectrum instruments
Hi! Thanks Julie: I had forgotten about this other limitation of the old
style calculations: Where to stop?
With the RIMpro approach (boxcar cohort programming) this is never an issue
because the proportion of spores that survives multiple drying, etc becomes
nil and drops out of the calculations. Yet another advantage of handling
proportions and probabilities instead of yes/no rules.
Vincent
De : apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] de la part de Juliet Evelyn Carroll
[j...@cornell.edu]
Date d'envoi : 26 avril 2011 13:12
À : Apple-crop discussion list
Objet : Re: [apple-crop] spectrum instruments
The 24 hour time frame used in NEWA was decided on by Bill Turechek when he was
the extension tree fruit pathologist at Cornell and is primarily based on the
work by Becker and Burr on interrupted wetting events. Prior to that NEWA had
used 8 hours.
The tricky part comes in combining a combined event with another event... when
does one stop combining events. In some cases, if a dew period is counted,
then the infection event could go on and on and on.
Julie
NEWANEWANEWANEWANEWA
Juliet E. Carroll, PhD
Project Leader, NEWA
Network for Environment Weather App's
NYS IPM Program, Cornell University
630 W. North St., Geneva, NY 14456
315-787-2430, j...@cornell.edu
NEWA Pest Forecasts, newa.cornell.edu
-Original Message-
From: apple-crop-boun...@virtualorchard.net
[mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of Vincent Philion
Sent: Tuesday, April 26, 2011 12:11 PM
To: Apple-crop discussion list
Subject: [apple-crop] RE : spectrum instruments
Hello ms Los.
In a nutshell: pathologists seldom agree on anything.
;-)
More seriously, 24 hrs was suggested by MacHardy based on different sources and
is a OK value.
However, there is field data on potted plants that show SOME ascospore survival
for many days.
That's one of the many reasons why yes/no rules cannot be used for scab
models. Instead, the relative risk of each component should be treated as a
population process with a average and deviation: some spores are quicker, some
are more tolerant, etc.
... that's how RIMpro calculates risk
Vincent
De : apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] de la part de Los, Lorraine
[lorraine@uconn.edu] Date d'envoi : 26 avril 2011 10:25 À : Apple-crop
discussion list Objet : Re: [apple-crop] spectrum instruments
Hello All,
I have a few Spectrum machines and have seen the discrepancies between the
different models. As someone else mentioned, one of the reasons is probably
related to the issue on how to decide if 2 or more wetting events should be
considered one continuous wetting event. The NEWA (Network for Environment and
Weather Applications), http://newa.cornell.edu site says Two successive
wetting periods are considered a single uninterrupted wetting period if the
intervening dry period is 24 hours. When I compare the NEWA data from an
orchard in CT to nearby orchards with Spectrum machines, the NEWA site has
indicated infections when the Spectrum machines did not.
Do Plant Pathologists agree on how to decide if 2 wetting periods should be
combined?
Thanks,
Lorraine Los
Entomologist and Fruit Crops IPM Coordinator University of Connecticut
From: apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] On Behalf Of Jon Clements
[jmcext...@gmail.com]
Sent: Sunday, April 24, 2011 7:02 PM
To: Apple-crop discussion list
Subject: {SPAM?} Re: [apple-crop] spectrum instruments
Yea, look at me, given my old(er) age -- the NRVART (Newspaper Readability
Venturia Ascospore Release Threshold) depends on: the light level (civil
twilight, nautical twilight, astronomical twilight?
see: http://en.wikipedia.org/wiki/Twilight) , distance reading the Newspaper
(far is probably better I am farsighted, oh not really, actually I am
presbyoptic, see:http://en.wikipedia.org/wiki/Presbyopia), font size
(obviously), and whether or not I can find my eye glasses. (Forgetfullness,
sorry, not in Wikipedia, but my bi-focal glasses are no-line TransitionsTM,
CriizalTM no-glare/reflections, about $250 each at Costco or WalMart if I buy
the cheaper frames.) Oh, and does the NRVART include reading the newspaper on
an iPad?
But BTW, I can perfectly relate to the PDBA fireblight index!
Sorry to downgrade an otherwise excellent discussion!
:-)
Jon
On Sun, Apr 24, 2011 at 6:20 PM, Dave Rosenberger da...@cornell.edu wrote:
Hey, Dan --
I believe that the reading a newspaper threshold for
ascospore discharge was a verbal comment from either Gadoury or
MacHardy. Given my failing memory, I can't be absolutely certain that
my recollection is correct. Anyway, this may be one of those rules of
thumb that never make it into the scientific literature,
