Host: burley tobacco (Nicotiana tabacum (burley type)
Description: The young leaves of frenched plants are narrowed and drawn with chlorosis along the margins. The network of veins is a distinct dark green. As the leaf develops, only the midrib elongates, producing a thick straplike-leaf. Terminal growth ceases and a stunted plant with many small, narrow, distorted leaves results. Frenching is usually classified as a physiological disorder, but studies indicate that frenching can be caused by a toxin formed by Bacillus cereus, a bacterium commonly found in the soil. Frenching is often associated with soils of high pH and/or poor internal drainage. Proper soil drainage, a pH level below 6, and adequate fertilization will be beneficial in preventing frenching.
Image type: Field
Image location: United States
Specimen in collection: No
Name: R.J. Reynolds Tobacco Company Slide Set
Organization: R.J. Reynolds Tobacco Company
Country: United States