Yale University EliScholar – A Digital Platform for Scholarly Publishing at Yale Yale School of Forestry & Environmental Studies School of Forestry and Environmental Studies Bulletin Series 1943 White Pine Blister Rust in Western North America J. L. Mielke United States Department of Agriculture Follow this and additional works at: https://elischolar.library.yale.edu/yale_fes_bulletin Part of the Environmental Sciences Commons, and the Forest Sciences Commons Recommended Citation Mielke, J. L., "White Pine Blister Rust in Western North America" (1943). Yale School of Forestry & Environmental Studies Bulletin Series. 56. https://elischolar.library.yale.edu/yale_fes_bulletin/56 This Newsletter is brought to you for free and open access by the School of Forestry and Environmental Studies at EliScholar – A Digital Platform for Scholarly Publishing at Yale. It has been accepted for inclusion in Yale School of Forestry & Environmental Studies Bulletin Series by an authorized administrator of EliScholar – A Digital Platform for Scholarly Publishing at Yale. For more information, please contact [email protected]. YALE UNIVERSITY· SCHOOL OF FORESTRY Bulletin No. 52 WHITE PINE BLISTER RUST IN WESTERN NORTH AMERICA BY J. L. MIELKE, B.S.F., .M.S., PH.D. Associate Pathologist, Division of Forest Pathology, Bureau ofPlant Industry, Soils, and Agricultural Engineering, Agricultural Research.Administration, United States Department ofAgriculture NEW HAVEN y ale University 1943 A Note to Readers 2012 This volume is part of a Bulletin Series inaugurated by the Yale School of Forestry & Environmental Studies in 1912. The Series contains important original scholarly and applied work by the School’s faculty, graduate students, alumni, and distinguished collaborators, and covers a broad range of topics. Bulletins 1-97 were published as bound print-only documents between 1912 and 1994. Starting with Bulletin 98 in 1995, the School began publishing volumes digitally and expanded them into a Publication Series that includes working papers, books, and reports as well as Bulletins. To celebrate the centennial of publishing at the school, the long out-of-print Bulletins 1-97 were scanned to make them available as pdfs to a broader audience. A caution: the scanning process is not perfect, especially for print documents as old as some of these, so the readers’ indulgence is requested for some of the anomalies that remain despite our best efforts to clean them up. Eve rything published from 1912-present is available on the School’s websit e (http://environment.yale.edu/publications ) for free download. Nothing in the Series requires copyright permission for reproduction when intended for personal or classroom use. Bound copies of everything published in the Series from 1912 to the present are also available in the Yale University libraries and archives and can best be accessed by contacting the School of Forestry & Environmental Studies librarian. The publication of the results of this investigation was made possible by the Charles Lathrop Pack Foundation at Yale University. The original manuscript was submitted as a dissertation in partial fulfillment of the requirements for the degree of Doctor ofPhilosophy in Yale University. CONTENTS Page INTRODUCTION 1 ORIGIN OF WHITE PINE BLISTER RUST 2 INTRODUCTION TO NORTH AMERICA 3 Eastern North America 3 Western North America 3 WHITE PINES OF WESTERN NORm AMERICA 5 THE RUST ON PINES 8 Relative Susceptibility of Western White Pines 8 Development of the Rust on Pines 9 Mode of infection 9 Incubation period IO Pycnial production 12 Aecial production 13 Canker Elongation 18 Determination of the Year of Infection on Pines 21 Rate of Intensification and Damage 22 Some Factors Affecting the Infection of Pines 26 Time of pine infection 26 Germination of the teliospores and sporidia 26 Time required for pine infection 31 Rain in relation to pine infection 33 Fog in relation to pine infection 35 Dew in relation to pine infection 36 Receptivity and susceptibility 38 Vigor of the host 39 Resistant individuals within a species 39 Size of tree in relation to infection 40 Relative virulence and abundance of sporidia from different ribes species 41 Heavy ribes infection and premature leaf cast 41 Influence of foliage screens on pine infection 42 Effective Distance of Dissemination of the Sporidia 43 THE RUST ON RIBES 46 Ribes in the West and Their Susceptibility 46 Development of the Rust on Ribes 50 Parts of the plant attacked and mode of infection 50 Incubation period on ribes 51 The uredial stage 53 The telial stage 56 WHITE PINE BLISTER RUST Page Some Factors Influencing Infection of Ribes 58 Infection resulting from aeciospores 58 Infection resulting from urediospores 62 Some Effects of Aeciospore Source on Ribes Infection 65 Effect on Ribes of Annually Repeated Heavy Infection 66 Time of Telial Development on Some Western Ribes 67 SCOUTING FOR THE RUST 71 EARLY HISTORY OF BLISTER RUST IN THE WEST 72 SPREAD OF THE RUST BY YEARS 75 Spread from 1910 to 1913, Inclusive 75 Spread from 1914 to 1921, Inclusive 77 Spread in 1922 83 Spread in 1923 84 Spread from 1924 to 1926, Inclusive 88 Spread in 1927 93 Spread in 1928 97 Spread from 1929 to 1935, Inclusive 98 Spread in 1936 102 Spread in 1937 103 Spread in 1938 105 Spread from 1939 to 1942, Inclusive 108 GENERAL ASPECT OF SPREAD 110 DISSEMINATING AGENCIES AND SPORE STAGES INVOLVED 114 POSSIBLE LIMITS OF LONG-DISTANCE SPREAD 116 RELATION OF WEATHER TO SPREAD AND INTENSIFICATION OF THE RUST 119 WAVELIKE CHARACTER OF SPREAD 9F THE RUST 127 RATE AND DIRECTION OF SPREAD OF THE RUST 130 SOME RELATIONS OF RIBES SPECIES IN THE SPREAD OF THE RUST 137 PINON RUST: ITS COMPLICATION IN THE SPREAD OF BLISTER RUST 139 SOME BIOLOGICAL FACTORS UNFAVORABLE TO DEVELOP. MENT OF THE RUST 141 STRAINS OF WHITE PINE BLISTER RUST 142 SUMMARY 142 ACKNOWLEDGMENTS I¢ REFERENCES CITED 147 ILLUSTRATIONS Figures Page 1. Range limits of western white pine (Pinus montieola) and sugar pine (P.lambertiana). 2. Known pine infection centers regarded as having become established in 1913. 3. Known pine infection centers regarded as having become established in 1917 or 1918 shown as triangles, and centers ofprevious origin as circles. 81 4. Known pine infection centers regarded as having become established in 1920 and 1921 shown as triangles, and centers of previous origin as circles. 82 5. Known distribution of Cronartium ribieola on ribes in the West in 1922 shown by dots. Shaded area is the composite range limits ofwhite pines in the West. 6. Known distribution ofCronartium ribieola on ribes in 1923. Crosshatching represents general infection of this host. Dots are infections at outlying points. Shaded area is composite range limits ofwhite pines in the West. 7. Known pine infection centers regarded as having become established in 1923 shown as triangles, and centers of previous origin as circles. Hatching is area of general pine infection. 89 8. Known distribution of Cronartium ribieola on ribes in 1925. Crosshatched areas are regions where the rust was general on these hosts. Dots are places where infected bushes were found outside these areas. Shaded area is composite range limits of white pines in the West. 9. Known distribution of Cronartium ribieola on ribes in 1927. Hatched areas are regions where the rust was general in occurrence on these hosts. Dots are places where infected bushes were found outside these areas. Shaded portion is composite range limits of white pines. 95 10. The distribution of Cronartium ribieola on pines in 1927-28. Hatched areas are regions ofgeneral pine infection. Advance centers outside are designated as follows: circles are known pine infection centers that became established in 1923 and previously; squares are known centers regarded as originating in 1925 or 1926; triangles are all known places where pine infection became established in 1927 or 1928. Those re­ garded as of 1928 origin are relatively few in number, but are included with those of 1927 because the probable year of origin is sometimes difficult to determine. Throughout the West generally very little pine infection occurred in 1928 because of the extreme dryness of the sum­ mer and fall seasons. 96 11. Known distribution of Cronartium ribieola on ribes in 1928. The area over which the rust was known to be general in occurrence on these hosts is designated by crosshatching. Dots are places where infected bushes were found outside this area. Shaded portion is composite range limits of white pines. 100 WHITE PINE BLISTER RUST Figures Page 12. Known distribution of Cronartium ribicola on pines (broken line) and ribes (solid line) in the West to 1936, inclusive. Known spread to ribes in 1937 shown by circles. Shaded portion is composite range limits of white pines. 106 13. Known limits of Cronartium ribicola on pines (broken line) and ribes (solid line) in the West to 1942, inclusive. Shaded portion is composite range limits of white pines. II I 14. A small Pinus monticola infected with Cronartium ribicola. The tree has been tapped gently so as to jar loose the aeciospores. Two clouds of these spores are plainly visible. (Photograph by Bureau ofEntomology and Plant Quarantine, U.S.D.A.) II8 TABLES Page 1. Place of origin of blister rust cankers on Pinus monticola. 35 2. Decrease in amount ofblister rust infection on Ribes lacustre and R. divari- catum with increase in distance from the aeciospore source. 66 3. Precipitation at Vancouver, British Columbia. 75 4. Average monthly precipitation during the growing season in various re- gions of the West. 132 WHITE PINE BLISTER RUST IN WESTERN NORTH AMERICA INTRODUCTION HITE pine blister rust (Cronartium ribicola, Fischer) needs no W introduction to American plant pathologists and foresters. Aided by the developed forms of transportation of man and by his constant urge for new and better forms of plant life, the fungus was enabled to escape from its native Asian home and to establish itself first in Europe and then in America.