LANCASTER, Pa. — Blue mold has been found growing in several tobacco fields around Lancaster county.
Under warm moist growing conditions, this disease can spread quickly and has the potential to significantly damage the local crop. Growers need to be aware of the threat and take appropriate action.
Several products are available to control blue mold, including those with the active ingredients Dimethomorph (brand names: Forum and Acrobat); Mancozeb (brand names: Dithane, Roper DF Rainshield and Manzate Pro-stick); Quadris; and Actiguard.
It is important to keep in mind that all these products work best as a preventative and protectant; therefore, for best results they should be applied before the disease is found.
Dimethomorph fungicide should not be applied alone. The label requires that it be combined with another product, such as Mancozeb, to prevent the development of resistant strains of Blue Mold. The combination has been proved to be effective and can be used until the threat has passed.
Multiple applications at seven to 10 day intervals will be necessary while rainy humid weather conditions persist.
Growers who have questions about control and prevention should check with their local buying representative. Lancaster Leaf Tobacco also has a prerecorded hotline at 717-239-4414 for its growers and others to stay abreast of the situation.
Source: Jeff Graybill, Lancaster County Agronomy educator.