Adam H. Putnam, Commissioner - Richard D. Gaskalla, Director

Cooperative Agricultural Pest Survey Program
(CAPS)


soybean rust on soybean leaf

Soybean Rust Web Site

In response to the recent introduction of Phakospora pachyrhizi, or soybean rust, into the United States, CAPS is working with the USDA-APHIS-PPQ and the Florida Department of Agriculture to facilitate surveillance and reporting of soybean rust (SBR) in Florida.


CAPS Soybean Rust Photo Galleries


Soybean Rust General Information

Soybean rust is a serious disease causing crop losses in other parts of the world. Two fungal species, Phakopsora pachyrhizi (also known as the Asian species) and P. meibomiae, cause soybean rust and are spread primarily by windborne spores that can be transported over long distances. Asian soybean rust, P. pachyrhizi, the more aggressive of the two species, was first reported in Japan in 1903 and was confined to the Eastern Hemisphere until its presence was documented in Hawaii in the mid-nineties.

closeup of soybean rust lesions on a leaf

Soybean rust symptoms are similar for P. pachyrhizi and P. meibomiae species. Symptoms begin on the lower leaves of the plant as small lesions that increase in size and change from gray to tan or reddish brown on the undersides of the leaves. Tan lesions, when mature, consist of small pustules surrounded by a slightly discolored deadened area with masses of tan spores on the lower leaf surface. Reddish brown lesions have a larger reddish brown deadened area, with a limited number of pustules and few visible spores on the lower leaf surface. Once pod set (pod growth) begins on soybean, infection can spread rapidly to the middle and upper leaves of the plant.

Host Range: P. pachyrhizi is capable of infecting more than 90 species of legumes (plants having pods that split open when dry); however, the number of legumes infected in nature is unknown. Kudzu, an invasive species that is a fast-growing vine, is widespread in the United States and could serve as a reservoir for the soybean rust pathogen. Some other common hosts are yellow sweet clover (Melilotus officinalis), vetch (Vicia dasycarpa), medic (Medicago arborea), lupine (Lupinus hirsutus), green and kidney bean (Phaseolus vulgaris), lima and butter bean (Phaseolus lunatus), and cowpea or blackeyed pea (Vigna unguiculata). See the APHIS/USDA Soybean Rust Data Sheet online for a more complete list of hosts.


Soybean Rust In Florida


Go to:    2002   |   2002-2003   |   2003-2004   |   2005

2002
In support of the National Initiative on Soybean Bean Rust (SBR), the Division of Plant Industry (DPI) conducted a statewide surveillance program in Florida. This was a joint effort of DPI inspectors with participation of USDA-APHIS personnel, FDACS/DPI-CAPS staff, and extension specialists from UF/IFAS stations at Homestead, Quincy, Marianna, and Milton and Jay townships. Dr. X.B. Yang, Associate Professor at Iowa State, also participated in this surveillance program.

Florida was divided into four zones for the epidemiological niches for SBR surveys on legumes including commercially-grown soybean, butter beans, velvet beans, and scarlet runner beans, as well as the invasive kudzu vine, Pueraria lobata. The zones established were:
Zone 1 - South Florida;
Zone 2 - Central Florida;
Zone 3 - North Florida; and
Zone 4 - Panhandle counties of Florida.


2002 - 2003
A total of 93 legume sites representing kudzu, soybean and various commercial legumes in each of the four zones of Florida were visited 52 or more times during 2003 (Kudzu sites represented 29 of these 93 sites). All the surveys for detection of SBR were negative. However, the common bean rust was detected on many legumes in Zone 1 (but not on kudzu, soybean or velvet bean). All survey site GPS coordinates were recorded and mapped for all 4 zones reported. Some details are given below:

Zone 1 (South Florida) – Since legume planting primarily starts in late September in South Florida, biweekly surveys were done from October 2002 to March 2003 followed by monthly surveys thereafter until September 2003, for a total of 17 surveys completed. A total of 51 bean sites under commercial cultivation, plus an additional three kudzu sites and four soybean sites were surveyed for SBR. No SBR was found.

Zone 2 (Central Florida) – (primarily Hernando and Pasco counties) Eleven (11) kudzu vine sites were identified from April 2003 to September 2003 and a total of 11 surveys at biweekly intervals were conducted. No SBR was found.

Zone 3 (North Florida) – 12 kudzu sites were established primarily in Marion, Alachua, Jefferson, Leon, and Gadsden counties. Eight (8) biweekly surveys were conducted at these sites for SBR detection. In addition, three more soybean sites planted by area growers in Jackson, Calhoun and Gadsden were surveyed nine times. No SBR was found.

Zone 4 (Panhandle-North Florida) – Seven kudzu sites were established in Santa Rosa and Okaloosa counties. These sites were surveyed seven times from May to September 2003. No SBR was found.


2003 - 2004
Early to mid-2004 surveying proceeded uneventfully in Florida. Then, in September 2004 Hurricane Ivan landed in the Florida panhandle and spread the SBR spores it carried from South America all across northwest Florida as well as the southeastern United States. One month later, in late November, SBR was detected for the first time in Florida in Gadsden County, and by the end of the year it had been detected in 16 more counties. Nearly all detections were on kudzu vine; a few were on soybeans. Some (not all) survey notes are included below as well as a table summarizing the SBR finds in 2004.

Zone 1 (South Florida)
July 2004:
Miami-Dade County Survey (Homestead) - During the spring and early summer, both soybeans and kudzu sites were monitored for soybean rust. Later, only kudzu is available and there are only three sites. The major site is at the University of Florida's TREC. No SBR was found.

Zone 4 (Panhandle-North Florida)
August and September 2004:
CAPS personnel surveyed nine counties comprised of: Calhoun, Escambia, Gadsden, Holmes, Liberty, Okaloosa, Santa Rosa, Walton and Washington counties.
Survey of kudzu during August 5-22. No SBR was found.
Survey of soybeans during September 2-October 19. No SBR was found.

Zone 1 (South Florida)
December 2004:
Miami-Dade County Survey – Two soybean locations, as well as other edible bean locations and kudzu, were visited once per week. No SBR was found.
Collier County Survey – Additional surveys were conducted in residential coastal areas and in Wiggins Pass State Park to investigate the predictions of a new USDA study showing SBR spore dispersal from Hurricane Ivan affecting coastal areas including Collier County. No SBR was found.

Zone 4 (Panhandle-North Florida )
October and November 2004:
Leon, Madison, Wakulla counties surveyed during Oct-Nov 2004. No SBR was found.
Leon, Madison, Wakulla counties surveyed during Nov 22-24. SBR was found in Gadsden, Leon, and Madison.
Escambia County Survey during November 24-26 on kudzu and soybeans hampered by severe weather. SBR was found.
Walton County Survey during November 27 on soybeans hampered by severe weather. SBR was found.


CAPS SOYBEAN RUST SURVEY 2004
MONTH COUNTY
CUMULATIVE
January No SBR reported.
0 counties
February No SBR reported.
0 counties
March No SBR reported.
0 counties
April No SBR reported.
0 counties
May No SBR reported.
0 counties
June No SBR reported.
0 counties
July No SBR reported.
0 counties
August No SBR reported.
0 counties
September No SBR reported.
0 counties
October No SBR reported.
0 counties
November Gadsden, Escambia (SBR found on soybeans and kudzu);
Alachua, Madison, Walton, Washington (SBR found on soybeans);
Jefferson, Jackson, Leon, Holmes, Santa Rosa, Calhoun, Bay, Marion, Okaloosa (SBR found on kudzu).
15 counties
December Levy (SBR found on soybeans);
Taylor (SBR found on kudzu).
17 counties

As of the close of 2004, soybean rust was found in a total of 17 counties in Florida: Escambia, Santa Rosa, Walton, Holmes, Washington, Bay, Jackson, Calhoun, Gadsden, Leon, Jefferson, Madison, Taylor, Alachua, Marion, Levy, and Okaloosa.


2005
Since soybean rust was found at the end of the previous year, in January 2005, Florida set up nine survey zones to monitor any further occurrences of SBR. The zones were further refined in March 2005 and Zone 9 (the Panhandle area) was split into two zones, resulting in a new total of 10 survey zones.

By the end of December 2005, soybean rust has been found in the following 23 counties:


CAPS SOYBEAN RUST SURVEY 2005
MONTH COUNTY
CUMULATIVE
January No SBR reported.
0 counties
February Pasco (SBR on kudzu)
1   county
March Hernando (SBR on kudzu)
2 counties
April Marion, Miami-Dade (SBR on kudzu)
4 counties
May No SBR reported.
4 counties
June Jefferson, Leon (SBR on kudzu)
6 counties
July Escambia, Gadsden (SBR on soybeans)
8 counties
August

Hamilton (SBR on soybeans and kudzu)
Alachua, Lee, Hillsborough, Taylor
(SBR on kudzu)
Madison, Columbia, Calhoun, Holmes, Santa Rosa, Okaloosa, Jackson, Walton, and Washington (SBR on soybeans)
22 counties
September No SBR reported.
22 counties
October Duval (SBR on kudzu)
23 counties
November No SBR reported.
23 counties
December No SBR resported.
23 counties


Other information about Soybean Rust



Above photos courtesy of the USDA

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