Quietly, Rust Becoming More Active In South

Soybean rust, which survives on leaves of kudzu as well as soybean plants, was not active early this year in Gulf Coast states, where it is annually detected first during the growing season. Hot, dry weather, including severe drought in Texas, has kept the rust spores from spreading through the air.

The most recent report was in a commercial research plot in Marion County, FL on Aug. 17. Two days prior, soybean rust was reported in nine new counties in Mississippi, all in commercial soybean fields, and soybean rust could no longer be detected in Texas. On Aug. 13, soybean rust was reported in Tensas County, LA on soybeans, and in Suwannee County, FL on kudzu. In 2009, soybean rust has been found in seven states and 54 counties in U.S., and in two states and five municipalities in Mexico.

Florida
“Soybean rust is continuing to develop in Florida,” says James Marois, University of Florida plant pathologist. “Since Aug. 5, five new counties have become positive, and there are now 14 positive counties in Florida. Tropical Storm Claudette is bringing large amounts of rain to the panhandle and expected to travel northwest.

Marois advises Florida growers and retailers to “be on the lookout for soybean rust. With the recent rains and the maturing crop we are likely to begin to encounter field infections.”

Mississippi
Soybean rust was detected Aug. 13 in a commercial soybean field just west of Stoneville/Leland. According to Tom Allen, Mississipi State University (MSU) plant pathologist and Troy Koger, soybean Extension specialist, “the soybeans were at the R7 growth stage. Levels of rust within the field were low. The soybean field had NOT received an R3/R4 fungicide application.”

The following day, soybean rust was reported in commercial soybean fields in Carroll, Grenada, Humphreys, Leflore, Montgomery, Sunflower, Yallabusha, and Yazoo counties. “Rust levels were extremely low in all of the fields save for one field in Montgomery County, immediately east of Winona, MS,” say Allen and Koger. “All soybean fiels were beyond R5.7, so they are out of the woods and would not require treatment.

Louisiana
According to Clayton Hollier, Louisiana State University plant pathologist, “three commercial fields of soybeans were found to be positive this week — all in Iberia Parish. Incidences were 18 percent, 7 percent, and 4 percent respectively and were in either R7 to R8 depending on location.”

Hollier adds that “Tensas Parish was positive for one location in a research plot with 10 percent incidence. The beans were in R6-7.”

Texas
As of Aug. 15, soybean plants are maturing throughout Texas, at least at pod fill or more mature. However, there are plants in the seedling stage in the Lower Rio Grande Valley, which will be the fall crop there, according to Tom Isakeit, Texas A&M University plant pathologist.

“There is still no rust at any the soybean sentinel sites in Texas,” Isakeit says. “The rust at one kudzu site, in Livingston, Polk County, in east Texas, is no longer detectable. Continued dry weather in central and southern Texas will not support establishment and development of rust.

“Recent rains in east Texas have not increased the risk there, as there is apparently no source of spores to start an epidemic,” he adds. “At this time, no preventative fungicides are recommended anywhere in the state.”

Isakeit also observes that “mineral deficiencies — particularly iron — are becoming apparent in some fields undergoing moisture stress. Some of these symptoms may resemble rust.”

Missouri
Because of the proximity of the recent Arkansas and Mississippi detections, Missouri officials have put their soybean rust scouts on alert. The findings are about 250 miles from southeast Missouri.

“Soybean rust has not been detected in Missouri this year,” says Allen Wrather, University of Missouri (MU) Extension plant pathologist. “This is the first find of rust this year in those two states. The weather during the next few weeks will greatly impact the spread of rust.”

Soybean rust has been found in Missouri four of the last five years, but always late in September or October, near harvest. Wet weather in Missouri this spring delayed planting. “Soybean maturity and harvest will be later than normal,” Wrather says. “Rust that develops in September might damage late-maturing soybean plans and reduce yield.”

For most of the 2009 growing season, prevailing winds have been from the northwest, bringing cooler than normal weather to the region. That may change with the coming hurricane season, Wrather says.

Leave a Reply

Latest News
Crop Protection Products in storage
Crop InputsNewsweek: World Is ‘Awash In Glyphosate’
February 11, 2016
The world is awash in glyphosate, the active ingredient in the herbicide Roundup, produced by Monsanto. It has now become Read More
Crop InputsEPA: Let’s Talk Imidacloprid, Bees On February 18
February 11, 2016
EPA will hold an online technical briefing on its preliminary pollinator risk assessment for imidacloprid, a neonicotinoid insecticide, on Feb. Read More
ManagementThe latest on Syngenta-ChemChina Deal
February 11, 2016
Executive Editor Paul Schrimpf invites Jackie Pucci and Dave Frabotta from sister publication AgriBusiness Global to discuss the latest developments Read More
AdjuvantsUniversity of Illinois Confirms Adjuvant’s Perfor…
February 11, 2016
An independent University of Illinois study has shown that WETCIT adjuvant, now with TransPhloem technology, provides greater herbicide uptake and Read More
Crop InputsSyngenta’s Acuron Flexi Receives EPA Approval
February 11, 2016
Growers looking to control their toughest weeds with flexibility will have access to Acuron Flexi corn herbicide from Syngenta, now Read More
EquipmentAGCO Showcases White Planters 9800VE Series Planters AT…
February 11, 2016
AGCO unveiled the new White Planters 9800VE Series planter during the 2016 National Farm Machinery Show in Louisville, KY. The Read More
EquipmentCase Unveils 2000 Series Early Riser Planter At NFMS
February 10, 2016
Case IH revealed the all-new 2000 Series Early Riser planter to media and attendees at the opening of the National Read More
Syngenta Sign
Crop InputsSyngenta: Keep Ag In Mind During Election Season
February 10, 2016
As presidential candidates stake out their 2016 election platforms and key priorities, growers and their business partners should seek opportunities Read More
Crop InputsMarrone Bio Innovations Submits New Bio-Fungicide For E…
February 9, 2016
Marrone Bio Innovations, Inc. (MBI) today announced that it has submitted a new biological fungicide (MBI-110) to EPA. The broad spectrum Read More
Crop InputsWeed Expert: Adding A Second Herbicide Not Always Easy
February 9, 2016
In my last post, I reviewed some recent research that suggests one of the best ways to delay the evolution Read More
Crop InputsGenetic Literacy Project: Farmers Need More Herbicide C…
February 9, 2016
There are two things that I think just about every weed scientist can agree on, writes Andrew Kniss for The Read More
HerbicidesWeed Expert Warns North Dakota Growers Of Coming Herbic…
February 9, 2016
Ford Baldwin painted a bleak picture of weed control at a recent workshop here exploring the future of ag production, Read More
HerbicidesWSSA Announces New, Updated Free Web Resources
February 9, 2016
Today the Weed Science Society of American (WSSA) announced that new and updated educational materials for both weed scientists and Read More
Soybean field
FungicidesFour Arysta Fungicide Formulations Given FIFRA Approval…
February 8, 2016
Arysta LifeScience North America recently announced the issuance of Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Section 2(ee) Recommendations for Read More
FungicidesAgri-Fos Systemic Fungicide Plus Receives EPA Registrat…
February 8, 2016
Vivid Life Sciences has announced the EPA registration of Agri-Fos Systemic Fungicide Plus, a highly concentrated active ingredient phosphite fungicide, Read More
Crop InputsBayer Contests EPA’s Decision On Valuable Insecticide F…
February 5, 2016
Crop Science, a division of Bayer, has announced it has refused a request by the Environmental Protection Agency (EPA) to Read More
Wheat Field North Dakota
Seed/BiotechSyngenta Wins Seed Fraud Suit Against South Dakota Grow…
February 5, 2016
Syngenta has obtained a $25,000 settlement from Paul and John Mayclin, Mayclin Farms, Plankinton, SD, in response to their Plant Read More
ManagementOABA Annual Conference Wraps Up In Columbus
February 5, 2016
More than 300 Ohio AgriBusiness Association (OABA) members and industry professionals were on hand to engage in collaborative learning and Read More