The relationship of iron to the brown spotting in grey flue-cured tobacco

• Published in: International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes Vol. 38; no. 7; pp. 553 - 559
• Main Authors: Arnold, Neville, Barthakur, Nayana, Binns, Michael
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1987
• ISSN: 0883-2889
• DOI: 10.1016/0883-2889(87)90204-8

The radioisotope 55Fe and the element Fe were used to determine if this element was related to the brown spotting in leaves of grey flue-cured tobacco ( Nicotiana tabacum L.) plants grown under greenhouse conditions. The distribution pattern of 55Fe was identical to the distribution of spots in grey tobacco. 55Fe was also found to be more concentrated in the leaf tip than in the middle or basal sections. The distribution of 55Fe paralleled the sequentially observed development of spots in leaves of greenhouse and field-grown plants. When hydroponically-grown tobacco plants were treated with 5–35 ppm Fe, the grey index distribution (a measure of grey tobacco symptoms) in top and middle leaves was similar to the pattern in Fe content of tobacco leaves. The highest grey index was found in top and middle leaf positions with 35 ppm Fe treatment. When Fe in solution was increased from 35 to 65 ppm, grey index in top leaves decreased but was unchanged in middle leaves. Examination of the minor vein system of grey tobacco leaves showed no Fe deposition in the vein system. These studies clearly show that Fe is associated with the speckling effect that develops in grey flue-cured tobacco.