Pioneer Hi-Bred experts are urging growers to keep a watchful eye on Goss’s wilt this year – particularly if they experienced light to heavy infections last year. Pioneer Research Scientist Scott Heuchelin says Goss’s wilt has a long history of wreaking havoc in corn fields in the western Corn Belt and is expanding its boundaries north and eastward. Agronomists and researchers say the yield-robbing disease is spreading as far north as Canada and east across the Midwest into Indiana. Once the bacterium infects the field – it may persist year after year – making it crucial for growers to identify the disease. If Goss’s wilt is present – Pioneer notes there is no chemical cure. Growers are encouraged to minimize their risk by selecting resistance hybrids in the coming planting seasons.
According to Heuchelin – growers should learn to correctly identify Goss’s wilt to prevent recurring disease issues in future years. He says the disease can easily be confused with environmental conditions like drought stress or sun scald – as well as other leaf blights or nutrient deficiencies. The first step is scouting for the distinguishing characteristics of Goss’s wilt – which can occur at any growth stage. In the seedling stage – early infection can be systemic and result in discolored vascular tissue with slimy stalk rot; a buildup of bacteria in the vascular bundles inhibiting the plant’s ability to transfer water; and stunted growth where the plant eventually wilts and dies as if drought stressed. The midseason signs and symptoms include distinct dark green to black ‘freckles’ within or just outside of leaf lesions; shiny or glistening patches of dried bacterial ooze on the lesions – similar to a thin layer of varnish; and Water-soaked streaks – along with tan to gray lesions that run lengthwise on the leaves.
Because in-season management options of Goss’s wilt are very limited – Heuchelin says the best strategy is prevention in the off-season with genetic resistance. He says choosing a hybrid with high levels of Goss’s wilt tolerance is the best line of defense – especially if the field has a history of previous infection.