Pheno-climatography of spring peach bud development


Richardson, E.A.; Seeley, S.D.; Walker, D.R.; Anderson, J.L.; Ashcroft, G.L.

HortScience 10(3): 236-237

1975


A model has been developed that relates the stages of spring bud development of 'Redhaven' and 'Elberta' peaches (Prunus persica (L) Batsch) to an accumulation of growing degree hours following rest completion. The accumulation of growing degree hours is based on a lower limit of 4.5°C and an upper limit of 25°.

Pheno-climatography
of
Spring
Peach
Bud
Development'
E.
Arlo
Richardson,
Schuyler
D.
Seeley,
David
R.
Walker,
J.
LaMar
Anderson,
and
Gaylen
L.
Ashcroft
Utah
State
University,
Logan
Abstract.
A
model
has
been
developed
that
relates
the
stages
of
spring
bud
development
of
`Redhaven'
and
`Elberta'
peaches
(Prunus
persica
(L)
Batsch)
to
an
accumulation
of
growing
degree
hours
following
rest
completion.
The
accumulation
of
growing
degree
hours
is
based
on
a
lower
limit
of
4.5°C
and
an
upper
limit
of
25°.
The
susceptibility
of
peach
trees
to
cold
damage
becomes
greater
as
the
buds
develop
in
the
spring.
Peach
buds
may
survive
-27°C
during
midwinter,
but
as
warmer
weather
occurs
after
completion
of
rest,
growth
begins
and
cold
hardiness
rapidly
dissipates
(5).
In
a
previous
paper
(6)
an
equation
was
presented
for
modeling
rest
using
orchard
temperature
data.
This
chill
unit
model
developed
by
Richardson
et
al.
has
been
used
to
determine
the
time
when
the
accumulation
of
growth
units
should
begin.
In
this
paper
a
model
is
presented
that
allows
a
forecast
of
the
approximate
timing
of
stages
of
bud
growth
and
development
after
a
tree
has
completed
its
interval
of
rest.
After
rest
completion
temperature
above
some
base
level
will
result
in
growth
and
bud
development.
In
general,
the
amount
of
development
that
occurs
in
a
given
day
increases
with
temp
above
the
base
level.
We
assume
no
growth
in
buds
held
below
their
base
temp.
Many
citations
can
be
found
which
relate
the
phenological
development
of
different
plants
to
some
form
of
heat
unit
or
growing
day
accumulation
(e.g.
2,
3,
7).
Two
li
mitations
occur
in
early
models
developed
for
fruit
trees.
First,
the
accumulation
of
energy
is
begun
on
a
fixed
calendar
date
for
each
given
location
and
second,
it
is
assumed,
that
within
the
range
of
temp
normally
found
in
the
free
air,
the
rate
of
growth
continues
to
increase
with
temp.
Studies
at
Utah
State
University
have
shown
that:
1)
The
time
a
tree
completes
winter
rest
may
vary
by
as
much
as
8
weeks
between
seasons.
2)
Peach
trees,
which
had
completed
rest
fail
to
show
signs
of growth
after
being
held
for
several
months
in
chambers
1
Received
for
publication
September
25,
1974.
Published
with
the
approval
of
the
Director
of
the
Utah
Agricultural
Experiment
Station
as
No.
1901
of
the
Journal
series.
Supported
in
part
by
a
grant
from
the
Four
Corners
Regional
ConMinion
under
project
No.
422-300-039.
controlled
at
4.5°C
(40°F).
3)
Peach
twigs
that
had
completed
rest
show
the
maximum
rate
of
bud
development
between
26°
and
27°C
in
growth
chambers.
The
fact
that
the
linear
increase
in
growth
rate
with
increasing
temp
holds
only
over
a
li
mited
range
and
varies
for
different
plants
was
recognized
by
researchers
several
years
ago.
For
these
reasons
a
new
growing
degree
day
model
for
corn
was
developed,
which
used
a
50°F
lower
limit
and
an
86°F
upper
limit
(1).
This
model
has
been
accepted
by
the
industry.
Another
model
for
cool
-temperature
crops
uses
a
base
of
40°F
and
an
upper
limit
of
77°F
(8).
The
studies
at
Utah
State
University
indicate
that
`Elberta'
and
`Redhaven'
peaches
respond
quite
closely
to
the
model
proposed
for
cool
-temp
plants
and
these
limits
have
therefore
been
used
in
the
model
proposed
in
this
paper.
As
the
phenological
development
of
peach
trees
was
observed
in
greenhouse
and
growth
chamber
studies,
we
recognized
the
need
for
a
smaller
scale
energy
unit
than
the
growing
degree
day
(GDD)
and
developed
the
growing
degree
hour
(GDH)
model.
This
model
uses
the
same
limits
as
the
growing
degree
day
model.
One
growing
degree
hour
Celsius
(GDH°C)
is
defined
as
1
hour
at
a
temp
1°C
above
the
base
temp
of
4.5°C.
GDH's
are
calculated
by
subtracting
4.5°
from
each
hourly
temp
between
4.5°
and
25°.
All
temp
above
25°
are
assumed
equal
to
25°;
thus
t
he
greatest
accumulation
for
any
1
hou
r
i
s
20.5
GDH's.
The
use
of
the
GDH
in
place
of
the
GDD
model
becomes
even
more
significant
when
the
accumulatio
n
of
energy
units
obtained
by
using
th
e
two
models
early
in
the
growing
seas
on
is
compared.
A
comparison
of
the
accumulations
obtained
using
n
ormal
temp
at
the
Salt
Lake
City
Airport
between
March
1
and
April
18,
indi
cates
1/3
more
energy
units
accumulated
using
the
GDH
than
the
GDD
m
o
d
el,
Since
the
tree
responds
to
energy
minute
by
minute
and
not
just
day
by
day
this
difference
is
quite
important.
In
this
present
study
6
`Redhaven'
peach
trees
(5
years
old)
w
ere
transplanted
into
27
-gallon
containers
early
in
the
fall.
After
leaf
drop,
th
e
trees
were
placed
in
a
cold
storage
room
at
4.5°C
until
their
chilling
requirements
were
satisfied.
The
trees
were
maintained
at
this
temp
until
needed,
and
then
allowed
to
develop
in
a
fiberglass
greenhouse
maintained
at
15.5
±
4°C.
Temp
were
recorded
with
standard
Weather
Service
thermograph
s.
P
h
e
n
o
1
o
g
i
c
al
stages
published
by
Washington
State
University
were
used
(4).
In
the
first
test,
2
trees
placed
in
the
greenhouse
at
2
PM
on
Dec.
26,
1972
reached
full
bloom
Jan.
13,
17
days
later
(Table
1).
Comparable
trees
in
a
second
test
initiated
Jan.
10,
1973
at
4:30
PM
reached
full
bloom
on
Jan.
28,
1973.
The
averages
of
the
growing
degree
hours
obtained
in
these
2
tests
(Table
1)
were
used
to
develop
our
model.
To
evalute
the
model
in
the
field,
dates
of
full
bloom
of
`Redhaven'
peach
trees
in
Logan
and
Salt
Lake
City,
Utah
during
the
1971-72
season
were
related
to
their
GDH
accumulations
after
Table
1.
Pheno-climatography
of
`Redhaven'
peaches
grown
in
the
greenhouse.
Stage
description
Test
1
accumulation
(GDH
°
C)
Date
Test
2
accumulation
(GDH
°
C)
Avg
accumula
Date
(GD11
°
Development
begins
Bud
swell
Green
calyx
Pink
tip
First
bloom
Full
bloom
1981
2580
3710
4174
4926
0
Dec.
26,
'72
Jan.
I,
'73
Jan.
3,
'73
Jan.
8,
'73
Jan.
10,
'73
Jan.
13,
'73
0
Jan.
10,
'73
0
2705
Jan.
19,
'73
2643
3623
Jan.
22,
'73
366
7
4234
Jan.
24,
'73
4204
4918
Jan.
28,
'73
492
2
Table
2.
Calculated
and
observed
phenological
dates
for
`Redhaven'
peaches
1971
and
I
Rest
Location
completion
datez
Calculated
full
bloom
date
Salt
Lake
City,
Utah
Jan.
10,
1972
Logan,
Utah
Jan.
24,
1972
March
23,
1972
April
25,
1972
Observed
fill
bloom
date
March
25,
191
2
.
April
27,
1
97
zDetermined
by
the
chill
unit
model
(6).
YDetermined
by
greenhouse
studies,
see
Table
I.
236
HORTSCIENCE,
VOL.
10(3),
JUNE
lir
Ta
peaches.
pearh
es.z
Pilen°
-
climatology
for
"Elberta'
.
nt
stag
e
o
develo
pme
Fiat
Swe"
CalYX
green,
c
a
lyx
red
sc
a
pink
First
bloom
pull
bloom
p o
st bloom
...-----
/Ba
sed
on
climatological
and
phenological
data
for
'Elberta'
peaches
from
Prosser,
wsshington
for
the
years
1962-1964,
1
965.196
7
;
data
supplied
by
E.
L.
Proebsting.
yG
r
owing
degree
hour
accumulation
after
comp
letion
of
rest
as
determined
from
time
comp
l
e
tion
790
chill
unit
accumulation
(4).
Growing
degree
hr
°
C
accumulationY
SD
2167
2617
3056
3717
4239
5110
5972
650
533
509
674
658
447
559
com
pletion.
The
difference
in
each
case
between
the
observed
and
calculated
dates
of
full
bloom
Was
2
days
(Table
2).
Hourly
temp
for
this
and
other
field
studies
were
estimated
from
the
daily
maximum
and
minimum
values
(6);
GDH
were
calculated
from
these
hourly
estimates.
`Elberta'
peach
phenology.
Nine
years
of
phenological
data
for
`Elberta'
peaches
at
the
Prosser,
Washington
Experiment
Station
were
obtained
from
E.
L.
Proebsting.
Using
climatological
data
from
this
station
the
accumulations
of
GDH's
for
each
developmental
stage
were
computed.
Average
values
of
these
accumulations,
and
their
standard
deviations
are
shown
in
Table
3.
A
comparison
of
the
data
for
`Redhaven'
peaches
in
Table
1
with
those
for
`Elberta'
in
Table
3,
indicates
that
their
recognizable
stages
of
fl
ower
development
correspond
closely
for
any
given
energy
accumulation.
19
73-74
field
tests.
To
further
evaluate
the
model
for
both
peach
cultivars
relative
to
field
conditions
in
Utah,
weekly
phenological
observations
were
taken
during
the
Springs
of
1973
and
1974
in
13
peach
orchards
along
the
Wasatch
Front
(Payson
to
Brigham
City,
Utah).
Due
to
the
severe
cold
weather
in
Dec.
1972
many
trees
were
killed
and
those
that
survived
had
very
few
viable
blossoms.
Fortunately,
seven
orchards,
that
were
fairly
close
to
climatological
stations
in
the
U.S.
Weather
Service,
contained
sufficient
blossoms
to
permit
determination
of
most
of
the
phenological
dates.
The
same
orchards
were
used
in
1974.
In
almost
every
case
the
more
recognizable
stages
of
development
occurred
within
a
few
days
of
the
dates
predicted
by
the
model.
The
standard
deviation
of
the
difference
between
observed
and
calculated
full
bloom
dates
for
these
2
years
of
data
at
the
seven
orchards
was
3.3
days.
Conclusions.
Field
tests
of
the
combined
chill
unit
-growing
degree
hour
model
have
proved
its
usefulness
in
predicting
stages
of
phenological
development.
The
model
permits
an
evaluation
of
the
probable
effects
of
various
cultural
practices
in
an
orchard•
on
tree
development.
It
is
also
possible
to
predict
the
delay
in
bloom
development
that
can
be
obtained
by
cooling
the
buds
with
overhead
sprinklers.
The
model
was
used
during
the
past
2
years
in
this
manner
and
the
predicted
delay
of
the
full
bloom
date
was
within
1
day
of
the,
observed
date
during
both
years.
Literature
Cited
1.
Anonymous.
1969.
Total
growing
degree
days.
Weekly
Crop
and
Weather
Bul.
May
5.
2.
Anstey,
T.
H.
1966.
Prediction
of
full
bloom
date
for
apple,
pear,
cherry,
peach
and
apricot
from
air
temperature
data.
Proc.
Amer.
Soc.
Hort.
Sci.
88:57-65.
3.Arnold,
Charlesy. 1960.
Maximum
-minimum
temperatures
as
a
basis
for
comparing
heat
units.
Proc.
Amer.
Soc.
Hort.
Sei.
76:682-692.
4.
Ballard,
James
K.,
E.
L.
Proebsting,
and
R.
B.
Tukey.
1971.
Critical
temperatures
for
blossom
buds,
peaches.
Wash.
State
Univ.
Ext.
Cir.
373.
5.
Proebsting,
E.
L.,
Jr.,
and
H. H.
Mills.
1961.
Loss
of
hardiness
of
peach
fruit
buds
as
related
to
their
morphological
development
during
the
pre
-bloom
and
bloom
period.
Proc.
Amer.
Soc.
Hort.
Sci.
78:104-110.
6.
Richardson,
E.
A.,
S.
D.
Seeley,
and
D.
R.
Walker.
1974.
A
model
for
estimating
the
completion
of
rest
for
`Redhaven'
and
`Elberta'
peach
trees.
HortScience
1:331-332.
7.
Ross,
R.
C.,
and
E.
H.
Artington.
1966.
The
effect
of
varying
temperature
regimes
on
degree
days
to
bloom
in
"Elberta'
peach.
Proc.
Amer.
Soc.
Hort.
Sci.
88:239-244.
8.
State
Climatologist,
Idaho.
1972.
Definition
of
growing
degree
days.
Weekly
Crop
and
Weather
Report
Supplement
for
Idaho.
A
Method
for
Selecting
the
Optimum
Maturity
Distribution
for
Mechanical
Harvesting
of
Clingstone
Peaches
for
Processing'
B.
L.
Tyson,
G.
G.
Dull
2
U.S.
Department
of
Agriculture,
Athens,
Georgia
and
B.
K.
Webb
3
Clemson
University,
Clemson,
South
Carolina
Abstract.
High
speed
reflected
light
ectrophotometry
was
used
to
determine
an
'Received
for
publication
November
12,
1
974.
Agricultural
Engineer
and
Research
Chemist,
lespectively,
Richard
B.
Russell
Agricultural
Research
Center.
3
Agricultural
Engineer,
Agricultural
Engineering
Department.
Use
of
a
compuny
or
product
name
does
not
imitate
a
guarantee
or
warranty
of
the
toduct
by
the
U.S.
Department
of
iculture,
and
does
not
imply
its
approval
the
exclusion
of
other
products
that
may
be
suitable.
We
thank
Dr.
G.
F.
Leeper
for
assistance
with
statistical
analysis.
optimum
maturity
distribution
of
mechanically
harvested
clingstone
peaches
(Prunus
persica
(L.)
Batsch)
for
processing.
Succinic
acid-2,2-dimethylhydrazide
(SADH)
applied
at
pit
-hardening,
advanced
the
optimum
harvest
date
from
3
to
5
days
and
increased
the
yield
of
processable
fruit
from
62%
for
the
control
trees
to
80%
for
the
treated
trees.
Mechanical
harvesting
of
clingstone
peaches
is
a
once-over
operation
which
results
in
the
harvest
of
a
wide
and
continuously
changing
range
of
maturities.
This
often
is
the
most
serious problem
in
harvest
mechanization
(2).
Sims
et
al.
(7)
reported
on
effects
of
SADH
on
color
development
(at
a
given
firmness)
for
freestone
fruit
but
did
not
consider
its
effect
on
the
maturity
distribution
of
clingstones.
The
relationship
between
maturity
distribution
and
optimum
processing
recovery
can
be
critical:
if
too
much
fruit
is
immature,
total
recovery
of
processable
fruit
and
processed
quality
will
be
reduced;
if
immature
fruit
are
allowed
to
ripen,
the
quantity
of
over
-ripe
and
tree
-dropped
fruit
increases
and
total
recovery
decreases.
The
objective
of
this
study
was
to
develop
a
method
for
selecting
the
most
advantageous
time
for
once-over
harvest
by
determining:
1)
the
maturity
distribution
of
fruit
on
individual
trees
during
the
harvest
period
by
use
of
a
rapid
sorting
technique
and
2)
the
effects
of
SADH
on
maturity
distribution.
A
block
of
26
mature
trees
of
'Baby
Gold
7'
clingstone
peaches,
located
in
Greer,
South
Carolina,
was
used
for
this
work.
At
the
pit
-hardening
stage,
half
the
trees
were
sprayed
with
2000
ppm
SADH
at
15
liters/tree.
The
remainder
served
as
border
trees
and
controls.
Two
SADH
treated
and
2
control
trees
were
harvested
with
the
Clemson
peach
RTSCIENCE,
VOL.
10(3),
JUNE
1975
237