Title: Florida plant disease management guide
ALL VOLUMES CITATION PDF VIEWER THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00053871/00013
 Material Information
Title: Florida plant disease management guide
Alternate Title: Ornamentals and turf
Fruit and vegetables
General plant pathology, field crops and pasture grasses, fungicides, adjuvants and application techniques
Physical Description: v. : ; 28 cm.
Language: English
Creator: University of Florida -- Dept. of Plant Pathology
Florida Cooperative Extension Service
Publisher: The Extension
Place of Publication: Gainesville Fla
Frequency: annual
regular
 Subjects
Subject: Plant diseases -- Periodicals -- Florida   ( lcsh )
Pesticides -- Periodicals   ( lcsh )
 Notes
Statement of Responsibility: Plant Pathology Dept., University of Florida and Institute of Food and Agricultural Sciences, Florida Cooperative Extension, University of Florida.
Numbering Peculiarities: Issued in three volumes: v. 1, General plant pathology, field crops and pasture grasses, fungicides, adjuvants and application techniques; v. 2, Ornamentals and turf; v. 3, Fruit and vegetables.
General Note: Description based on: 1999-2000.
General Note: "SP-52"
 Record Information
Bibliographic ID: UF00053871
Volume ID: VID00013
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 44549741
lccn - 00229071
 Related Items
Preceded by: Florida plant disease control guide

Downloads

This item has the following downloads:

PG04900 ( PDF )


Full Text




PDM G-V3-41
UF UNIVERSITY of

UFFLORIDA
IFAS Extension



2006 Florida Plant Disease Management Guide:Okra1


Richard Raid and Aaron Palmateer2


Specific Common Diseases

Cercospora Leaf Blight (Cercospora
abelmoschi)

Symptoms: Leaf spots have no definite shape,
size or margin. The causal fungus appears as an
olivaceous to sooty-colored growth on the lower leaf
surface. Injured leaves will often roll, wilt and
abscise. This is usually not of economic importance
in commercial plantings.

Cultural Controls: There are no cultural or
chemical controls available for this problem under
present growing conditions in Florida.

Damping-Off (Pythium spp., Rhizoctonia
spp.)

Symptoms: This disease can affect plantings by
the fungi reducing seed germination or infecting
emerged seedlings. Cultural or environmental
conditions that delay the rapid germination of seed,
such as cool soil, may result in pre-emergence
damping-off. The soilbome fungi responsible for seed
decay can also infect young seedlings at or below the
soil line causing them to topple over and die.


Affected plants will exhibit soft, mushy roots and
stems or discolored areas on these plant parts.

Cultural Controls: Plant only when soil moisture
and temperature favor rapid germination. Apply a
seed treatment fungicide to protect seed during
germination.

Chemical Controls: Use a fungicidal seed
treatment. See PPP-6.

Powdery Mildew (Oidium sp.)

Symptoms: This disease is characterized by the
obvious white coating of fungal mycelium on lower
and upper leaf surfaces. Severe infection will cause
the leaves to roll upward and result in leaf scorching.
This disease can be particularly severe during the
winter cropping season in south Florida.

Chemical Controls: See PPP-6.

Southern Blight (Sclerotium rolfsii)

Symptoms: This disease occurs during warm,
humid weather. Okra plants exhibit a progressive wilt
symptom as the causal fungus infects the roots and
lower stem. During moist weather a coarse white


1. This document is PDMG-V3-41, one of a series of the Department of Plant Pathology, 2006 Florida Plant Disease Management Guide, Florida Cooperative
Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Date Revised: January 2006. Please visit the EDIS Web site at
http://edis.ifas.ufl.edu.
2. R. Raid, professor, Plant Pathology Department, Everglades Research and Education Center--Belle Glade, FL; A. Palmateer, assistant professor, Plant
Pathology Department, Tropical Research and Education Center--Homestead, FL; Florida Cooperative Extension Service, Insitute of Food and
Agricultural Sciences, University of Florida, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and
other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex,
sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service,
University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry
Arrington, Dean






2006 Florida Plant Disease Management Guide:Okra 2


fungal mycelium can be observed at the soil line
around and on the stem. In a few days, numerous
white nodules form on this mycelium. These
structures (sclerotia) turn brown with age and are the
size of a mustard seed. These sclerotia survive in the
soil and serve as survival structures for this fungus
over a number of years. Any movement of infested
soil will spread this disease problem.

Cultural Controls: Rotate to a grass crop in
fields with a high infestation of this fungus. Deep
plow infected crop debris to place most of these
sclerotia below the root zone of the next crop.
Amistar fungicide would suppress this disease when
applied to the soil by the stem prior to occurrence of
this disease. This disease is not listed on the Amistar
label.

Verticillium Wilt (Verticillium albo-atrum)

Symptoms: This is a fungal wilt disease of okra.
A slight leaf yellowing will be noted (usually on
lower, older leaves). Plants begin to exhibit an
increasing period of wilt around mid-day. Wilt
progresses from the lower to the upper foliage for
longer periods until the plant dies. Slight vascular
discoloration can be observed when the lower stem is
slit lengthwise. This disease is most likely to occur on
soil with a high pH such as in the Homestead/Florida
city area of Southeast Florida.

Cultural Control: Plant okra crops onto new land
or on land rotated away from such susceptible crops
as the solanaceous vegetables or strawberries. Good
rotation crops are grasses, cucurbits, and legumes.
Soil fumigants applied prior to planting can shorten
rotation time. Avoid over liming of the soil.

Wet Rot (Choanephora cucurbitarum)

Symptoms: Young and old blossoms, young fruit
and wounded leaf tissue may become infected. Newly
opened blooms will wilt and collapse. Fruit may
become infected from the blossom and affected plant
parts become covered with a dense white growth of
fungus that is whisker-like in appearance. These
whiskers (sporangiophores) develop purple-black
heads at maturity. Affected plant parts will soften, rot
and fall to the soil surface.


Cultural Controls: Improve air circulation by
avoiding dense plantings. In garden situations,
dislodge the flower from the fruit as soon as fruit set
has occurred.




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs