Title: Bulletin of the U.S. Department of Agriculture
Identifier: bulletinofusd10261050unit (find matches)
Year: 1913-1923. (1910s)
Authors: United States. Dept. of Agriculture
Subjects: Agriculture; Agriculture
Publisher: (Washington, D. C. ?) : The Dept. : Supt. of Docs. , G. P. O.
Contributing Library: American Museum of Natural History Library
Digitizing Sponsor: American Museum of Natural History Library

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UNITED STATES DEPARTMENT OF AGRICULTURE Mfe BULLETIN No. 1038 ;Mb n^fiw^ Contribution from the Bureau of Plant Indastrv JailkSiii^l^
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Contribution from the Bureau of Plant Industry WM. A. TAYLOR, Chief Washington, D. C. March 20,1922 PECAN ROSETTE: ITS HISTOLOGY, CYTOLOGY, AND RELATION TO OTHER CHLOROTIC DIS- EASES/ By Feedekick V. Rand, Pathologist, Lahoratory of Plant Pathology. CONTENTS. Page. Types of chlorotic plant diseases 1 Chloroses due to soil or atmospheric conditions , 2 Infectious chloroses 6 Studies of pecan rosette 13 Results of previous work 13 External signs of rosette 17 Page. Studies of pecan rosette—Continued. Histological and cytological studies 19 Subsidiary experiments 30 Probable nature of pecan rosette 31 Summary . 36 Literature cited 37 TYPES OF CHLOROTIC PLANT DISEASES. The chlorotic group of plant diseases to which pecan rosette be- longs has long been recognized and has presented to the investigator some of the most baffling problems in plant pathology. The potato- mosaic group began to assume alarming proportions in the British Isles and on the Continent toward the end of the eighteenth century and at the beginning of the nineteenth century (27, 45, 59).^ Peach, yellows was known and much written about in the United States near the beginning of the nineteenth century (69). Tobacco mosaic was first described by Mayer in 1886 (52), but more fully treated by Beijerinck in 1898 (17). Other well-known chloroses will readily come to mind in addition to those recently discovered or not so generally recognized. It is not the purpose of this paper to consider in detail all types of plant variegation. Chloroses have to do with the reduction or 1 The present study was largely carried out under the direction of Dr. R. A.. Harper, of Columbia University, and was completed under the direction of Dr. Erwin F. Smith, of the Laboratory of Plant Pathology, Bureau of Plant Industry. 2 The serial numbers in parentheses refer to " Literature cited " at the end of this bulletin. 76289—22 1

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