What is in this article?:
- How to Curb Goss Loss | Prevention is Main Tool in Dodging Gossâ€™s Wilt
- What we know about Goss’s wilt
What we know about Goss’s wilt
- The Goss bacteria (Cmn) spreads by wind, residue movement or with tillage implements. Infection occurs when the plant is wounded and the bacteria splash onto the plants from infected residue.
- Disease severity is related to May and June average daily temperatures and rainfall.
- The optimum temperature for bacterial growth is 81° F. Recent warmer temperatures may explain part of the increased incidence of Goss’s wilt.
- Stress in a field can cause the disease to act more aggressively.
- It can wipe out a field of corn.
- There are very susceptible hybrids and very tolerant hybrids.
- An infection early in grain fill can reduce yields by 50+%.
- It has a systemic wilt phase and a more common and damaging leaf blight phase.
- Goss’s wilt bacteria on surface crop residue can survive for at least 10 months.
- Pure cultures of the bacterium in soil only survived for two weeks or less. However the bacterium survived for at least 10 months in infested surface crop residue. When the crop leaves, stalks, cobs and ears were buried at 4 in. or 8 in., the bacterium was only detected in stalk residue after 10 months.
- Rotating to a non-host crop, such as soybeans, allows time for infested residues to break down and inoculum levels to decrease. Also, heat, competition with other microbes and low pH reduce the bacteria’s survivability.
- These weeds are known secondary hosts of Goss’s bacteria: green foxtail, shattercane, sudangrass, barnyardgrass and eastern gamagrass.
- These species are resistant to Goss’s wilt infection: oats, wheat, sugarbeet, barley, bromegrass, orchard grass, crab grass, proso millet, yellow foxtail, Johnson grass.
- Seed transmission of Goss’s wilt is not very common. One study found only one naturally occurring transmission in 12,864 seedlings.
- It develops on the tops of plants.
- It is most commonly transmitted at growth stage R5 or later.
- University of Nebraska research found 19% of newer Goss’s wilt isolates have changed compared to older samples of the bacteria.
- Our most reliable control tools in the meantime are:
A resistant hybrid
–Courtesy of Iowa State University Extension Plant Pathologist Alison Robertson and Bill Curran, Pioneer lead scientist for its Goss’s wilt hybrid development and screening program