E/6;~ \f REPORT OF THE TWENTY-NINTH ALFALFA IMPROVEMENT CONFERENCE July 15-20,1984 Lethbridge, Alberta, Canada REPORT OF THE TWENTY-NINTH ALFALFA IMPROVEMENT CONFERENCE July 15-20, 1984 Lethbridge, Alberta, Canada Reported by D. R. Viands, Secretary Dept. of Plant Breeding and Biometry 523 Bradfield Hall Cornell University Ithaca, NY 14853 J. H. Elgin, Jr., Executive Secretary USDA-ARS Field Crops Laboratory Bldg. 001, Rm. 335, BARC-W Beltsville, MD 20705 Thirtieth North American Alfalfa Improvement Conference to be held July 27-31, 1986 University of Minnesota St. Paul, Minnesota Distribution of Conference Report The conference report is sent to all those on the North American Alfalfa Improvement Conference mailing list. It is also sent to libraries that have requested copies of previous reports. For research leaders to identify libraries that should be added to our mailing list, a complete listing of them is provided for your information. If you are aware of new names that should be added to the Alfalfa Improvement Conference directory, or if you have a change of address, please send the Mailing List Questionnaire form at the back of this report to the conference secretary. LIBRARIES: University of California, Documents Dept. Berkeley, CA 94720 University of California, Government Documents Dept., Davis, CA 95616 Colorado State University, Fort Collins, CO 80521 Department of Genetics, Agricultural Experiment Station, New Haven, CT 06504 Hume Library of Federal Documents, Institute of Food and Agricultural Science, University of Florida, Gainesville, FL 32611 University of Hawaii, Documents Collection, 2425 Campus Road, Honolulu, HI 96822 John Deere and Co., John Deere Road, Moline, IL 61265 University of Illinois, Documents Library, 200D, Urbana, IL 61801 Indiana State Library, 140 N. Senate Ave., Indianapolis, IN 46204 Iowa State University, Ames, IA 50011 Enoch Pratt Free Library, 400 Cathedral St., Baltimore, MD 21201 USDA, National Agricultural Library, Current Serial Records, Beltsville, MD 20705 Michigan State University, Science Library, East Lansing, MI 48824 Dept. Agronomy & Plant Genetics, University, of Minnesota, St. Paul, MN 55108 University of Minnesota, St. Paul Campus Library, 1984 Buford Ave., St. Paul, MN 55108 Delta Branch Experiment Station, Stoneville, MS 38776 Linda Hall Library, 5109 Cherry St., Kansas City, MO 64110 University of Nebraska, Serials Divisions, University Libraries, Lincoln, NE 68588 Rutgers University, Agricultural Library, P.O. Box 231, New Brunswick, NJ 08903 Albert R. Mann Library, Acquisitions Division, Cornell University, Ithaca, NY 14853 New York State College of Agriculture and Life Sciences, Agricultural Experiment Station, Ithaca, NY 14850 North Dakota State University, Fargo, ND 58102 Oregon State University, Documents Division, Corvallis, OR 97331 Pennsylvania State University, Documents Section, University Park, PA 16802 Texas A & M University, College Station, TX 77843 Vermont Agricultural Experiment Station, Burlington, VT 05401 Steenbock Memorial Library, College of Agric. and Life Sciences, Univ. of Wis., Madison, WI 53706 INTA, Departmento de Genetica, CC 25, 1712 Castelar, Argentina NSW Department of Agriculture, State Office Block, Phillip St., Sydney, N.S.W. Australia Cameron Library, University of Alberta, Edmonton, Alberta, T6G 2El Canada Central Experimental Farm, AC, Ottawa, Ontario, K2E GC7 Canada Agriculture Canada, Library Recording, Ottawa, Ontario KIA OC5 Canada Station de Recherche, AC, 2650 Boulevard Hochelaga, Ste-Foy, Quebec, GlV 2J3 Canada Research Station, AC, 107 Science Crescent, Saskatoon, Saskatchewan, Canada S7N OX2 University of Saskatchewan, Government Publications Section, Saskatoon, Saskatchewan, Canada S7N OWO Research Station Library, Box 1030, Swift Current, Saskatchewan, S9H 3X2 Vyskumny Ustav Rastlinnej Vyroby, 921 68 Piestany, Bratislavska, Cesta 2795/122, CSSR-Czechoslovakia Grassland Research Institute, Hurley, Maidenhead, Berks, England Department of Agricultural Science and Applied Biology, University of Cambridge, Cambridge, England Plant Breeding Institute Library, Maris Lane, Trumpington, Cambridge CB2 2LQ, England Science Reference Library (A), 25 Southampton Buildings, Chancery Lane, London WC2A lAW England British Library, Lending Division, Boston Spa, Weatherby, West Yorkshire LS23 7BQ, England Bibliotheque I.N.R.A., Station d'Amelioration des Plantes Fourrageres, 86-600 Lusignan, France Station Centrale de Genetique et ,d' Amelioration des Plantes, Etoile de Choisy, Route St. Cyr, Versailles, France National Agricultural Library, Budapest I., Attila Ut 93, Levelcim: 1253, Budapest 13, Hungary George Forbes Memorial Library, Lincoln College, Canterbury, New Zealand Agricultural College of Norway, N-1432, AS-NLH, Norway Sveriges Lantbruksuniversitets Bib1iotek, S-750 07 Uppsa1a 7, Sweden Weibul1sho1m Plant Breeding Institute, Box 520, S-26l 24, Landskrona, Sweden Bernard Clement, Swiss Federal Inst. Tech., Gifts Section, Ramistrasse 101, CH-8092, Zurich, Switzerland Agricultural Univ. Library, P.O. Box 9100, 6700 Ha Wageningen, The Netherlands Library DeHaaf Foundation for Agricultural Plant Breeding, P.O. Box 117, 6700 AC Wageningen, The Netherlands Welsh Plant Breeding Station, Aberystwyth, Wales Universitats-Bibliothek, Abt. Zentra1bibliothek der Landbauwissenschraft, Box 2460, 5300 Bonn 1, West Germany Institut za Oplemenjivanje, Marulicev TRG 5, 41000 Zabreb, Yugoslavia TWENTY-HINTB HORTH AMERICAN ALFALFA IMPROVEMERT CORPERENCE Program Chairman - R. R. Kalton contents INTRODUCTION SPECIAL ADDRESSES Joint Meeting of the NAIC and FIWC - Welcoming Address--D.G. Dorrell .....•.•.•.•• 2 An Address to the National Alfalfa Improvement Conference--H.B.McEwen ...•.••••••• 3 Fifty Years of Progress in Alfalfa Improvement--D.F. Beard ••••••..•••....•..••.•• 6 ALFALFA DISEASES AND THEIR CONTROL Susceptibility of Certain Oilseed Crops to Verticillium albo-atrum from Alfalfa--G. Flores and S. Allen ...•.......••••••••••.........••••••......•.. 13 The Use of Histochemical Analysis in Distinguishing Verticillium Wilt Resistant Alfalfa Plants from Tolerant and Susceptible--Y.A. Papadopoulos, B.R. Christie, L.V. Busch, and S. Hindson •.•.........••..••..• 14 Verticillium Wilt of Alfalfa: Seed-borne Mechanism--H.C. Huang, M.R. Hanna, and E. G. Kokko ...••••.............•••••••............•••.••..••...... 15 Potential for Biological and Chemical Control of Verticillium Wilt of Alfalfa--R.L. Millar, D.W. Kalb, and A.P. Keinath .••........•.••••...••..••• 16 Survival of Verticillium albo-atrum in Alfalfa Tissues Fed to Ruminants or Buried in Manure--H.C. Huang, R. Hironaka, and R.J. Howard •••.•••••••.••• 17 Recent Studies at the Ottawa Research Station on Phytophthora megasperma f. sp. medicaginis Causing Phytophthora Root Rot of Alfalfa--M.A. Faris ••••.... 18 In Vitro Expression of Disease Resistance in Alfalfa to Colletotrichum trifolii--J. Cucuzza, J. Kao, and I. Kawaguchi ..••••••...•••..•........•.... 19 The Influence of Water Potential on Colletotrichum trifolii In vitro and on Anthracnose in Alfalfa--B.D. Thyr, W.W. Miller, and R.J. Cook ...........•... 20 Effects of Harvest Frequency and Soil Fertility on the Deve'lopment of Crown Rot of Alfalfa and the Implications on a Breeding Program--R. Salter, D.R. Viands, and C.C. Lowe •.•••••••••••.•••..••••.•.••..•.•••.•.•••.••••.••. 21 The Winter Crown Rot/Snow Mold Complex of Alfalfa in the Peace River Region of Alberta and British Columbia--J.G.N. Davidson .•..••...•.•..•..••......... 22 Techniques Useful in Disease Studies with Alfalfa--K.T. Leath, W.A. Kendall, and R.R. Hill, Jr ..••.••.•..••••••••••.......••••••••••••••••••••••••....... 23 Selecting for Resistance to Alfalfa Sickness--F.M. Katepa, J.L. Bolton, and P . D. Wa 1 ton •••.•........••••••••••••.........••••••••..•...........•••.•••.. 24 Relationship between Levels of Anthracnose Resistance and Performance of Alfalfa Cultivars--C.R. Grau, D.C. Arny, M.A. Hansen, and D.T. Caine .•••••.. 25 Progress in Breeding for Resistance to Crown and Root Rot_in Alfalfa--R. Michaud, C. Richard, and C. Gagnon •••••.••••••••..• ~~.••••••.•......•••••..... 26 Inheritance of Resistance to Verticillium Wilt in Vertus Compared to Maris Kabul--D.R. Viands and R. Salter ••.••••••••...•••••...•.•.••••.•...••.•••••. 27 Analytic Breeding of Alfalfa: Selection and Breeding at the Diploid Level for Resistance to Phytophthora megasperma f. sp. medicaginis--M.J. Havey and D. ~. Maxwell •.••••••...••••..•.•••••••••••••••••••••••.•••.•••.•.••••••• 28 ALFALPA Rl:TROGEN PIXATION AND RBIZOBIAL STUDIES Ineffective Root Nodules of Alfalfa: A Model System to Study Host-Microbe Compatibi1i ty--C. P. Vance ••.•.•••••••••••.•......•....•..•...•••............ 29 Immunological Studies of Rhizobium me1i1oti--P.E. Olsen and W.A. Rice ••.•...•.•.. 30 Effect of Population Crossing on Traits Associated with Nitrogen Fixation-- D.L. Jessen, O.K. Barnes, S. Stade, C.P. Vance, and G.H. Heichel ...•••.....• 31 Nitrogenase Activity of Alfalfa Grown Alone at Different Seeding Rates and in Mixtures with Grasses--H.A. Burity, M.A. Faris, and B.E. Coulman ••.•........ 32 Preliminary Evaluation of Yield and Nitrate Reductase Activity (NRA) Among Alfalfa Populations Selected for Differences in NRA--D.L. Nelson, O.K. Barnes, C.P. Vance, and G.H. Heichel ....••••.••.••....••••••.••••.....•••..• 33 The Utilization of Nitrogen from l5N-Labelled Legume Residues by Barley--R.W. Sheard, T. Bruu1sema, and B.R. Christie ....•.•••.••.•....••..••..•.........• 34 Changes in Alfalfa Root