The Dickinson press., 1913-02-08
CHAR CTER OF D0DDER1
on Host for Support and
It's Food Supply
At First Growth 70 Apparently ln,Io.
"'"eant, but With Rapid Inersass
+; IN Branching Soon Becomes
f. Hard 70 Control.
(By =. H HuLAANl

Dodder 10 q parasite deriving its
1ood not from the soil. but directly
from the crop plants which it ipfests
In this respect 1t L. unlike the ordi.
nary weeds Of the farm. It starts
from a seed. at first deriving it,
nourtshment from the food supplv
stored within the seed. During this
period 1t develops a slender, thread.
IKE and leafless stem. It Is the habit
OF the dodder to climb by twining, and
the young stem swats about In search
OF a support. Failing to find q suit.
able support it dies when the food
stored within the seed is exhausted.
II a suitable support. such as the
stem. leaf stems. or even leaf blades
OF a clover. is found, the dodder ran.
idly twines about It, sending out from
Its stem numerous suckers which
penetrate the tissues of the plant upon
which 1t rests, termed the host plant.
The dodder Is subsequently dependent
on Its host for both its mechanical
support and it's food supply. The twin
Ing of the dodder stem and the cling.
Ing eject of the suckers secure the
mechanical support necessary, while
the penetration Of the suckers to the
sap-conveying tissues Of the host
plant insures direct communication
with the food prepared by the latter
TOR its own use.
After becoming established on the
host plant the part Of the dodder
plant below the point Of attachment
dies. Above this point the plant
makes rapid growth, branching re.
peatedly. its branches ultimately
forming a tangled mass of threadlike
hlaments when under conditions
favorable for luxur1ant growth. At
first the growth is apparently insig-
niacant. but with the rapid increase
In the branching the total growth
soon become very conspicuous, and
In some instances progresses with ex-
cepttonal rapidity, rendering its con
troll very difficult.
Dodder depends on prepared food.
Independent food manufacture be-
comes unnecessary. and consequently
the plant Is devoid Of leaves, as we'll
as of root. and usually Is devoid Of
the green color common to other
plants. Certain species are strongly
ttnged with green, however, and
doubtless are capable Of food produc-
ton to some extent.
Sections Of the dodder stems re-
moved from the main plant retain
their vitality and power Of coiling
and producing suckers for several
days at least Under favorable condi-
ions. In consequence Of this, If
pieces of plants are allowed to re-
main in contact with a suitable host
plant for a short time they become at
to the latter and form new
centers Of growth. In this way new
of the pest may become e.
in the field.
Dodder plants are to be distinguish
ed by their slender. threadlike steams,
which are lemon yellow, orange, or
pink. They may appear to confne
their attack to a single plant in a
place or may spread uniformly from
plant to plant. either near the ground
or from the tops of the plants. Small
white flowers, mostly in clusters, are
produced by midsummer. The flowers
may be few and scattered, or, owing
to thrifty growth, they may be more
numerous and. becoming crowded.,
form dense punches.
Seeds ripen throughout the central
States from the middle of July
into September. AS a rule, the dod-
ders are profuse seed producers. but
seed production is strongly Influenced
by the character Of the host, its
as a crop. and by the con-
dition of the weather during the flow.
ertng season Of the dodder.