- Nearly all tobacco black shank in Georgia is Race 1. Most of the varietal resistance available is for Race 0. Long-term control of black shank will depend on development of new varieties.
GEORGIA TOBACCO GROWERS with history of black shank in fields were encouraged to make additional applications of one pint of Ridomil Gold or equivalent rates of generic materials to soil following planting. The preventive measure wasn’t enough in some fields.
Georgia’s spring weather provided perfect conditions for black shank, a major tobacco disease, to brew in water-damaged tobacco fields, according to Georgia’s tobacco specialist. Once plants get the disease, there is little to nothing growers can do about it.
In a blog posted May 31, J. Michael Moore, University of Georgia Cooperative Extension tobacco specialist, says drier soils in recent days and temperatures in the 90s started black shank-infected plants to wilting, and protective chemistry applied in the greenhouse has long been hampered by heavy rainfall in the state's tobacco-growing region.
According to Moore:
“Protection from the 8 oz. / A of Ridomil Gold applied in the transplant water has been subject to numerous rainfall events and more than six weeks since transplanting for most Georgia tobacco.
Growers with any history of black shank in selected fields to be planted this year were encouraged to make additional applications of one pint of Ridomil Gold or equivalent rates of generic materials to be applied to the soil following transplanting with an additional application prior to the last cultivation. Application to the plants is not curative and does not provide protection. The chemical must be taken up by the roots prior to infection.
Additional rainfall will further reduce the efficacy of any remaining material in the soil. Previous race determination work in Georgia indicated that nearly all black shank in the state is Race 1. Most of the varietal resistance available to growers is for Race 0. Long-term control of black shank will depend on development of new varieties with new sources of resistance, long rotations of tobacco in diseased fields and use of preventive chemicals to help control the incidence of disease.”
Read more of Moore’s blog at Georgia Tobacco Hotline.