Group Title: Circular
Title: Black shank of flue cured tobacco
Full Citation
Permanent Link:
 Material Information
Title: Black shank of flue cured tobacco
Series Title: Circular
Physical Description: 1 folded sheet (6 p.) : col. ill. ; 23 cm.
Language: English
Creator: Whitty, E. B
Mullin, R. S ( Robert Spencer ), 1915-
Miller, C. R
Clark, Fred
Dean, Charles Edgar, 1929-
University of Florida -- Agricultural Extension Service
Publisher: Agricultural Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1967
Subject: Flue-cured tobacco -- Florida   ( lcsh )
Flue-cured tobacco -- Diseases and pests -- Control -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: prepared by E.B. Whitty, R.S. Mullin and C.R. Miller ; in cooperation with Fred Clark and C.E. Dean.
General Note: "November, 1967."
 Record Information
Bibliographic ID: UF00084348
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 79274956

Full Text




-Cross section of tobacco stems showing
ank damage.



Black shank of tobacco was first identified
in Florida in 1924 in shade-grown tobacco in
Gadsden county. It has since
HISTORY persisted there as a serious
tobacco disease. It was dis-
covered in flue-cured tobacco near Winston-
Salem, North Carolina in 1931 and in South
Carolina in 1948. Outbreaks occurred in
Georgia in 1959 and on several flue-cured
tobacco farms in Florida in 1961. By 1966,
the disease, which is a major obstacle to
successful production of flue-cured tobacco in
Florida, had appeared in every major
tobacco-growing county in the state.

Black shank is caused by the soil-borne
fungus, Phytophthora parasitica var. nico-
tianae. The disease almost al-
CAUSE ways makes it first appearance
in low areas of a field. Once in-
troduced into a field, it is able to survive in
the soil for five or more years.

Tobacco may be attacked by the black
shank fungus at any stage of its growth.
Wilting is the first symp-
SYMPTOMS tom; however, since other
organisms may also cause
tobacco to wilt, this alone is not sufficient to
identify the disease. Part or all of the large
lateral roots of plants infected with the black
shank fungus may be blackened and dead.
As the disease progresses, the leaves die and
turn brown, and the stalk becomes black near
the soil line. In some cases, this stalk dis-
coloration may extend well above the soil line.
In advanced stages, the pith in the dark-
ened stem area becomes wafered or separated
into discs. This wafering of the pith is a
good symptom for identification of black
shank. Once the fungus gains entrance, sus-
ceptible varieties seldom survive, and death
may occur within one week after the first
symptoms appear.
Symptoms in the plant bed are similar to
those in the field, in that wilting is accom-

. Should your farm become infested
ack shank, switch to a variety of
having high resistance to thi

le was prepared by E. B. Whitty, Assistant
ist, R. S. Mullin, Plant Pathologist and
ler, Assistant Plant Pathologist, in cooper-
th Fred Clark, Agronomist, Agricultural
ent Stations, and C. E. Dean, Associate
ist, North Florida Experiment Station.

(Acts of May 8 and June 30, 1914)
A tural Extension Service, University of Florida
I States Department of Agriculture, Cooperating
M. O. Watkins, Director

Fig. 3-Death of
plants caused by
Black Shank.

Fig. 2-Black Shank
infestation at early I
stage of tobacco

panied by a blackening of all or part of the
root system.

The black-shank fungus may be spread in
a number of ways. It can be carried from
an infested plant
DISSEMINATION bed to the field by
diseased s e e d -
lings. The disease can be spread from an in-
fested field by equipment, on shoes, by wind
and water erosion or by any other means that
result in the transportation of soil particles
from one area to another. Fields irrigated
with water from contaminated ponds or
streams may become infested.

If a grower observes wilted plants in his
field, he should immediately contact the
county agent and get the
CONTROL cause determined. If black
shank is identified as the
cause of wilting, precautions should be taken
not to carry infested soil out of the field on
tools, trucks, tractors or other equipment, or
on the feet of men or animals. Except for
harvesting, plants or plant parts should not
be removed from infested areas.

county agent. Black
Cited from an area by
iety, but losses from
iced by following a
and growing a re-

r be carried from the
on seedlings, every
w his own plants to
ad of this disease.
I bromide at recom-
roy the pathogen in
)ns must be taken to
i, which may occur
isted earlier. All to-
umigated for nema-
itode injury predis-
hank infection.

-e disease of tobacco.
nation of your farm
owing your own
; s, practicing crop
n and keeping off
f wilting of tobacco

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