TRANSACTIONS OF THE MISSOURI ACADEMY OF SCIENCE Vol. 18, 1984 Officers 1983·84 President: Albert R Gordon, Southwest Missouri State President-Elect Donald 1-l. Froemsdorf, Southeast Missouri State University Vice-President Nathan H Lincoln University Past President: Edward M. Emery, Monsanto Company Secretary: Alfred C. Robertson, Southeast Missouri State University Treasurer: Elizabeth E. Topping, Southwest Missouri State University Historian: Clayton H Johnson, University of Missouri-Columbia Director, Collegiate Division: Roland A Hultsch, University of Missouri-Columbia Director, Junior Division Adell Thompson, University of Missouri-Kansas Dean A Rosebery, Northeast Missouri State University Editorial Staff Editor.· John R Jones; Assistant Editor: Sandy Clark. School of Fisheries and Wildlife, University of Missouri, Columbia, MO 65211 Associate Editors: Biology: Jack R Wallin, University of Missouri, Columbia, MO 65211 Chemistry: John E. Bauman, University of Columbia, MO 65211 Engineering: Gary Mueller, University of Missouri, Rolla, MO 65401 Social Science Rex Campbell, University of Missouri, Columbia, MO 65211 Economics William Kurtz, University of Columbia, MO 65211 SEND ALL Iv1ANUSCR!PTS TO: Dr. John R Jones, Editor, Transactions of the Missouri P.cademy of Science, School of Forestry, Fisheries and Wildlife, of 112 Stephens Hall, Columbia, MO 65211 Publications of the Missouri of Science Transactions of the Missouri Academy of Science, Volumes 1-6, 9, 12, 13, 15, 16 & 17 6.00 Transactions of the Missouri Academy of Science, Double Volumes: 7 & 8, 10 & 11; Volume 18 . ....... ....... 10.00 Occasional Papers: 1. Symposium on Pests & Pesticides . ........ .2.50 2. Enzymic Characterization of Brown Recluse Spider Venom.. .......... 2.50 3. Timber-Wildlife Management Symposium.... ...... ........ 3.50 4. Callaway Plant Units I and !1, Preconstruction Environmental Monitoring ... .. ..... .. ....... .................. 3.50 5. Second Woody Ornamentals Disease Workshop '" ........ ... ' ..... .2.50 6. CANCELED 7. Proceedings of Cedar Glade Symposium . .......... 3.50 This journal is abstracted by the Bioscience Information Service and Chemical Abstracts Services. ISSN 0544--540X Transactions of The Missouri Academy of Science Table of Contents Sponsors of the Missouri Academy of Science .................................................................. 3 Biological Sciences Reaction of soybean cultivars to Macrophomina phaseo/ina as seedlings in the growth chamber and field P. R. Bristow and T. D. Wyllie........................................... .. ................................ 5 The hybrid status of Tridens oklahomensis (Feath.) Feath. S. M. Schuckman and C. L. Kucera .......................................................................... 11 Additional notes on rare, endangered and unusual Missouri fen plants S. L. Orzell ..................................................................................................................... 13 Secondary production in Isonychia bico/or (Ephemeroptera: Oligoneuriidae) D. M. Sullivan and M. S. Topping ............................................................................. 17 Ecological observations of eastern spotted skunks on the Ozark Plateau C. R. McCullough and E. K. Fritz ell ............................................................................ 25 Breeding range and population status of the greater prairie chicken in Missouri R. W. Cannon and D. M. Christisen ............................................................................ 33 Histologic cycle of the mourning dove crop P. Books-Blenden, T. S. Baskett and E. M. Brown ................................................ ..41 Chemical Sciences Thermal decomposition of bis(3-phenyl-3-methylbutanoyl) peroxide M. W. Mosher, R. L. Sloan, K. Hanrahan, G. W. Estes and M. D. Mosher ................................................................................................................. 55 Physical Sciences Solar radiation in southeast Missouri J. E. Tansil ..................................................................................................................... 61 Correlation of the St. Laurent Formation (Middle Devonian) near Belgique in northern Perry County, Missouri G. H. Fraunfelter ............................................................................................................ 73 History History of Missouri Junior Academy of Science 1957-1984 C. H. Johnson ............................................................................................................... 79 Abstracts Annual Meeting of the Missouri Academy of Science, Southeast Missouri State University, Cape Girardeau, MO, April27-28, 1984 Senior Division ............................................................................................................ 101 Collegiate Division ....................................................................................................... .113 Authors Index to Authors .............................................................................................................. 118 Instructions for Authors .................................................................................................... 120 Cover art by Tim Haithcoat, Master's candidate, School of Forestry, Fisheries and Wildlife, University of Missouri-Columbia Sponsors of the Missouri Academy of Science Support for the MISSOURI JUNIOR ACADEMY OF SCIENCE (Junior Division) has been received from Southwestern Bell Telephone Company and Union Electric Company. Two AAAS Awards (Kirkpatrick Trophies) are awarded to the two most outstanding high school students at the MJAS annual meeting. These students are given the opportunity to represent the state of Missouri at the annual meeting of the American Junior Academy of Science. Dr. John Paul Morris Award (traveling plaque and $25), provided by Mrs. John Paul Morris, is given each year to an outstanding young high school woman presenting a paper in the physical sciences. PATRON MEMBER: St. Joe Lead Company SUSTAINING MEMBERS: ASARCO, Inc., Southwestern Bell Telephone Com­ pany. INSTITUTIONAL MEMBERS have contributed funds to support the activities of the Academy on the basis of 11fz¢ per FTE student, with a minimum of $15.00 for colleges with less than 1,000 students. We wish to express our appreciation to the following institutions who were Institutional Members during 1983-84: Cardinal Newman College-St. Louis Missouri Western State College-St. Joseph Central Methodist College-Fayette Moberly Junior College-Moberly Central Missouri State University-Wmrensburg Northeast Missouri State University-Kirksville Cleveland Chiropractic College-Kansas City Northwest Missouri State University-Marysville Columbia College-Columbia Park College-Parkville Crowder College-Neosho Rockhurst College-Kansas City Culver-Stockton College-Canton School of the Ozarks-Point Lookout Drury College-Springfield St. Louis College of Pharmacy-St. Louis East Central Junior College-Union St. Louis University-St. Louis Fontbonne College-St. Louis St. Mary's Seminary College-Perryville Hannibal-La Grange College-Hannibal Southeast Missouri State University-Cape Girardeau Harris-Stowe State College-St. Louis Southwest Baptist University-Bolivar Kirksville College of Osteopathic Medicine-Kirksville Southwest Missouri State University-Springfield Lincoln University-Jefferson City State Fair Community College-Sedalia Lindenwood College-St. Charles Stephens College-Columbia Linn Technical College-Linn University of Missouri-Columbia Logan College of Chiropractic-Chesterfield University of Missouri-Kansas City Longview Community College-Lee's Summit University of Missouri-Rolla Maryville College-St. Louis University of Missouri-St. Louis Mineral Area College-Flat. River William Jewell College-Liberty Missouri Baptist College-St. Louis Missouri Southern State College-Joplin 1984 Bristow & Wyllie, Biological Sciences 5 Reaction of Soybean Cultivars to Macrophomina phaseolina as Seedlings in the Growth Chamber and Field1 P. R. Bristow Western Washington Research and Extension Center Washington State University Puyallup, WA 98371 T. D. Wyllie Department of Plant Pathology University of Missouri Columbia, MO 65211 Abstract: The reaction of seedlings of 14 soybean cultivars to Macrophomina phaseolina was assessed under suitable growth chamber conditions in an attempt to identify superior genotypes. The growth response of soybean cultivars to fungal attack by this soilborne pathogen varies with inoculum density. Cultivar responses in plant height, root volume and root and shoot weight ranged from stimulation in Dunfield to losses of 82-93% in Williams. Although the extent of growth changes for a given cultivar varied from 1 experiment to another, its relative position among tested cultivars remained essentially the same. Four susceptible cultivars, when tested in the field, became infected at a similar rate. These data suggest that growth responses of seedlings to infection by M. phaseolina may be useful in evaluating resistance to the charcoal rot disease. Key Words: Charcoal rot, resistance, soilborne Introduction Charcoal rot disease, caused by the soilborne fungus Macrophomina phaseolina (Tassi) Goid., is one of the most serious diseases of soybeans (Glycine max (L.) Merr.) in the southern half of the United States (Wyllie 1974). In Missouri, over 25% of commercial fields sown to soybeans in 1981 harbored populations of the fungus (Wyllie and McKelvey 1983) capable of causing measurable