Tobacco
What burley tobacco variety should you pick for 2009?
Source: Kenny Seebold, extension plant pathologist
When it comes to diseases in burley tobacco, black shank ranks right up there at the top of the list. Losses to black shank are higher each year than all other past problems combined. During the 2008 season, statewide losses to black shank were high, but did not reach the levels of 2007. Part of the reason for that was the widespread use of resistant varieties across Kentucky.
We've known for years that managing black shank involves several factors. Good sanitation and adequate land preparation are critical considerations, and crop rotation is a key factor. A good rotational strategy is to grow tobacco for one to two years in a field, followed by two to four years with another crop to prevent build up of the black shank pathogen. Fungicides can provide additional protection against black shank when used with rotation and resistant varieties.
So, which variety should you pick for 2009? The answer depends on the quality of the rotation scheme you use, the history of black shank in a particular field and whether or not race 1 of the black shank pathogen is present, like it is across most fields in the state.
Growers with no history of black shank can choose from a number of excellent varieties that have good yield potential and leaf characteristics but little or no black shank resistance. These include HB 04P and Hybrid 404. If a field doesn't have a history of black shank, pick a variety like TN 86, TN 90 or KT 200 only if you have been on a good rotation or you know disease has been light - that means less than 5 to 10 percent of the field having showed symptoms in the past.
If disease has been more severe, consider KT 204 or KT 206. KT 204 offers high levels of resistance to both races of the black shank pathogen. KT 206 was planted extensively in 2008 and has near-immunity to race 0 and the same high level of resistance to race 1 seen in KT 204. In University of Kentucky field tests and on growers' farms, KT 206 has outperformed other black shank-resistant varieties in terms of disease control and yield potential. An added benefit of KT 206 is moderate resistance to blue mold. New varieties such as Newton's 7371 or Rickard's HB 3307P have performed about as well as KT 204 in UK tests and specialists there say they would be good choices where disease is light to moderate.
Each year brings new challenges, but we can be certain that black shank will continue to be one of our main production constraints in 2009. Make plans now to pick the burley varieties that will perform best in your fields against black shank and get a leg up on this serious problem.
For more information on black shank-resistant burley tobacco varieties, contact the Scott County Cooperative Extension Service or Kenny Seebold, UK extension plant pathologist at 859-257-7445.
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