The life Span and Number of Leaves Produced by Sugarbeet Plants Infected with Cercospora beticola
1
G. L.
CRANE" AND
L.
CALPOLZOS"
I n trodlIction
lJelicola SacCo is all
tel fmd no pLl bl"
disease affects the
Such in formation
contribute to a
of the injury caused
this leaf spot disease.
how Cercospora
spot affects the life
span o[
leaves and the total number of leaves producecl by infected
plants.
Although
I eaves, we
ot
COLl
:VI aterials and Methods
The varieties used
and 6322-0
in the
Iowa.
rows surrounded
'which were
these were
small plots
Ten
spaced 22 inches
and ten
of the
\Ve measured life span
once a 'week
ence. The
ance in the
In this
Scientific Journal Series,
~rjnnCSOia
"with the Crops Rcs'--'arclt Diyi:"ion or the t',
Department of PI;ml P.:Hholog~"t UnIversity
at Yoder Brothers
Inc, Fort '\Iyc"r~, Flurida.
;} Department
J
in
now
OF THE
each week. even
week. In addition
the death of
estimate the
the season
dried
remnants,
A. S. S. B. T.
1-6 leaves a
each
we recorded
thus vve were able to
Total leaf production for
all living and dead
at harvest, October 6.
Results
The
of d [sease
leaves killed
disease
treatments at different dates:
with
other
By
there was severe
on the susceptible umprayed plants and moderate disease inci­
dence on the other
l\o leaves .
of the treatments
died due to
senescence; the
leaves which died
were killed by leaf
disease.
The total num her of leaves.
was counted on the
H when the
di {Ferellces
f-
z
« III
...l
CL
"­
(f)
w
>
10
9.
8:
«
7
...l
w
6
5
(..')
(..')
4
w
0
«
f­
0
«
w
0
3
2
I
0
2'(
JUNE
6
II
JULY
AUG.
SEPT
DATES OF OBSERVATION
,vert:
line
maneb.
with
sus·
VOL
16, No.1,
APRIL
43
1970
these two groups of
Total number of leaves 'was also
counted on the two varietie~ and the spray treatments at harvest
when the
was at its maximum. T'he average number
61 for
or
o{
lIn~prayed
treatments.
span
leaves. Some of the earliest
leaves sur­
vived to harvest; these leaves (U weeks old) were only on the
and resistant plants. and
these lea\'es
or no disease
the season. The earliest
leaves on the
all Sll bkilled hy
harvest.
it appears that leaves with 1
alive for ;It least I;l
and had we
than June 27. we may have found that the
free leaves would he even longer than 1;) weeks.
age of the leaves still alive was 1-;) 'weeks on the
plants and 7-L) weeks in the other trealments.
estimated the life span of leaves in a commercial
plants located at Hollandale, Minnesota. AI­
01 a
ran­
per
leaf
harvest.
Discussion and Conclusions
V\Y e assume that the Hum bel' oj
leaf scars present at harvest indicates the tolal
for the season
the
of the
first one or two
leaves).
we
our data obtained at harvest in .Masoll (
W indicate
and
diseased plants total leaf
the same, even
two
involved.
OF THE
A. S. S. B. T.
to
leaf spot disease
than could be' accounted
Literature Cited
(I)
R, E" D, E, FARt:S, L
cides for conlrol 01
Beet TechnoL 1,1
I-"1:\K:\VR,
SOl~;E,
1
J 9(j(j, Evaluation of
leal spot of sugar beets, J. Am, Soc.
(;Al,POUZOS,
0, C. 1966. Simulated hail
to sugar heets,
Sw" Croobton, Minnesota 21 p, (mimeo,
:"Jumbcrs in parentheses refer to literature" cited.
l},
of Minn,