Ways to Avoid Goss’s Wilt in 2012

Posted on August 15, 2011 by Shannon Latham, Vice President

Goss’s Wilt, which has plagued Nebraska corn fields since 1969, has been spotted in Iowa this season. Iowa farmers are searching for ways to protect yield potential yet this season, as well as avoid the problem in 2012, says ISU Plant Pathologist Alison Robertson.

There are three products that Robertson says she’s heard Iowa corn growers are trying to treat Goss’s Wilt: Procidic, Kocide and Intercept. Procidic is advertised as a broad spectrum fungicide and bactericide. However, Robertson isn’t aware of any published data for the effect of Procidic against bacterial diseases or use on corn. Kocide is not labeled for use on corn to manage Goss’s Wilt, so Robertson said it should not be used. A third product that Iowa growers are reportedly trying is Intercept. There is very little information available on this product, but it’s reportedly been used in Florida to control citrus canker, which is also caused by a bacterium.

Robertson is monitoring a corn field in Gilbert, Iowa, that had an application of Procidic, as well as an earlier application of Stratego YLD. She says she also will be evaluating fields where Intercept has been applied. At the end of the growing season, ISU researchers will study the effect of both products on Goss’s Wilt disease development and general plant health of the corn.

“Continuous corn production together with minimum tillage practices have in part contributed to the epidemic of Goss’s wilt we are witnessing in 2011,” says Robertson in a recent Wallaces Farmer article. ”Other factors include susceptible germplasm and stormy weather.”

To avoid Goss’s Wilt in 2012, farmers should keep recommended management practices in mind. Best practices include growing resistant corn hybrids, using crop rotation and crop residue management.

Seeing Signs of Goss’ Wilt in Latham Country

Posted on August 2, 2011 by Laura Cunningham, Marketing Coordinator

Guest Blogged by John Toft
CCA, Tekemah, NE

Symptoms of Goss’ Wilt were reported earlier this growing season in Nebraska and Iowa. With all of the storm damage in these areas, including hail and straight-line winds, it’s no wonder that we’re receiving even more reports now of Goss’ Wilt. Stalk bruising and leaf shredding provide ways for pathogens to enter the corn plant. High night-time temperatures, which we’ve also experienced recently, favor the spread of Goss’ Wilt.

Goss’ Wilt causes large lesions that start on the leave’s margins and eventually encompass the entire leaf. These lesions look very similar to Gray Leaf Spot injury. One simple, but not fool-proof, way to diagnose the difference is that Goss’ will have a waxy appearance due to the different

Note the waxy, shiny appearance to the lesions caused by Goss' Wilt

pathogens that cause the disease. Gray Leaf Spot is caused by a fungus while Goss’ is caused by a bacterium, which means Goss’ Wilt cannot be controlled by a fungicide. Effective control measures include crop rotation, tillage and hybrids that show genetic resistance. Latham’s 2012 lineup has a number of hybrids with excellent disease packages, so keep this in mind as you make your seed decisions in the coming months.

The bacterium responsible for Goss’ Wilt may infect the xylem, or water-conducting tissues of the plant, which results in wilting and death.

Seed selection is most likely going to play an even more important role as Goss’ Wilt becomes more prevalent. Bacterial wilt was first reported in Nebraska more than 40 years ago, and the list of states affected keeps growing. Goss’ Wilt has been identified in Kansas, Colorado, Wyoming, South Dakota and Iowa. The disease has also been confirmed in Illinois and Wisconsin, according to a NebGuide article, “Goss’s Bacterial Wilt and Leaf Blight of Corn,” published by the University of Nebraska—Lincoln Extension.

Scouting for SDS is Important

Posted on August 1, 2011 by Shannon Latham, Vice President

Sudden Death Syndrome (SDS) typically appears during the last week of July or the first week of August in Latham Country, so farmers are being advised to keep their eyes open for this yield-robbing disease. Cool, wet conditions at planting time can contribute to the severity of SDS.

“Although we do not expect SDS to be as widespread or as severe as the 2010 growing season, there have been some Iowa counties that have received higher-than-normal precipitation,” said ISU Plant Pathologist Alison Robertson in a recent Wallaces Farmer article. “We expect the risk of SDS in these counties to be higher since the development of this disease is favored by wet conditions.”

Scouting for SDS is important for several reasons:

Identifying fields or parts of fields with SDS can help with future management practices. These management tactics include reducing soil compaction since the disease has been associated with compacted soil; planting fields with a history of SDS towards the end of a planting schedule when soils may be warmer and drier; and testing for the presence of soybean cyst nematodes.
Cyst nematode is usually, but not always, associated with SDS. You may see more severe cases of SDS in soybean varieties that are SCN-susceptible. When selecting soybean seed, it’s best to read through the SDS score rather than judge a bean solely by SCN tolerance.
Planting resistant varieties, or avoiding very susceptible varieties, is the most effective way to reduce losses from SDS. Keeping good field records from year-to-year will help determine which characteristics are most crucial when selecting soybean varieties to plant in a given field in a given year. The following Latham® varieties carry excellent scores for SDS tolerance:

As you prepare to walk your fields, these videos shot last season by Soybean Product Manager Mark Grundmeier will explain what symptoms of SDS to look for in your fields. You might also enjoy watching Mark’s brief, but informative, videos on SDS management and prevention.