File:Bulletin (1889-1913.) (20396989296).jpg

Title: Bulletin
Identifier: bulletin2650unit (find matches)
Year: 1889-1913. (1880s)
Authors: United States. Office of Experiment Stations
Subjects:
Publisher: Washington, Govt. Print. Off
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: American Museum of Natural History Library

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
BULLETIN OF THE No. 40
Text Appearing After Image:
Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief, J January 15, 1914. THE MOSAIC DISEASE OF TOBACCO.1 By H. A. Allabd, Assistant Physiologist, Tobacco and Plant-Nutrition Investigations. INTRODUCTION. " Mosaic " is one of the most serious and widespread diseases known to affect the tobacco plant. This disease also is known locally as "calico," "gray-top," "mottled-top," "mottling," and "foxy" to- bacco. Especially in southern tobacco sections the term " f renching "2 is used to designate abnormal, sickly plants characterized by the de- velopment of stringy, very thick, and leathery leaves which may be free from mottling. It has not been determined whether this is dis- tinct from mosaic or only a somewhat different phase of this disease. In the tobacco sections of Kentucky and Tennessee "Wal- loon" is often used to denote mosaic or other abnormal appearances more or less closely resembling symptoms of the mosaic disease. The disease has also been termed "chlorosis." Finally, mosaic plants sometimes are spoken of as "brindle" or "mongrel." These terms 1 In a study of the mosaic disease of tobacco facts have been learned which throw con- siderable light on its nature and origin. It has been shown tliat it is communicable to plants of many genera of the solanaceous family and that aphides are sometimes active disseminators of infection both in the greenhouse and in the field. The fact tbat par- ticular insects are involved in the spread of the disease not only helps to explain the contradictory results obtained by previous investigators, but also serves to indicate means by which the disease can, to a greater or less extent, be controlled under practical field conditions. Since insects are involved in the spread of the mosaic disease both in seed beds and in the field and the practical control of this disease must depend primarily upon an intimate knowledge of the habits and distribution of species which may act as capable carriers of infection, this phase of the investigation has been taken up in cooperation with the Bureau of Entomology.âWm. A. Taylor, Chief of Bureau. 2 The term " frenching " or " frenched " is applied to sickly, spindling corn plants and peach trees as well as to tobacco plants. Its origin dates back to the settlement of Maryland when the English settlers applied the term " Frenchmen "â to weak, spindling tobacco plants as a term of contempt. See Clayton, John. A Letter ... to the Royal Society, May 12, 1688, giving an account of several observables in Virginia ... p. 19. (In Force, Peter. Tracts and Other Papers, Relating Principally to the Origin, Settle- ment, and Progress of the Colonies in North America, v. 3, Washington, 1844.) 13128°âBull. 40â14 1

Note About Images