REPORT OF THE TWENTY-SEVENTH ALFALFA IMPROVEMENT CONFERENCE

July 8-10, 1980 University of Wisconsin Madison, Wisconsin

Agricultural Reviews and Manuals Science and Education Administration ARM-NC-19 U.S. Department of Agriculture May 1981 REPORT OF THE TWENTY-SEVENTH ALFALFA IMPROVEMENT CONFERENCE

July 8-10, 1980 University of Wisconsin Madison, Wisconsin

Reported by D. K. Barnes, Permanent Secretary

Twenty-eighth Alfalfa I mprovement Conference to be held July 13-15, 1982 University of California Davis, California

Published by Agricultural Research, North Central Region Science and Education Administration U.S. Department of Agriculture ISSN 0193-3787 Peoria,lIlInols 61615 Distribution of Conference Report The conference report is sent to all those on the National Alfalfa Improvement Conference mailing list. It is also sent to libraries that have requested copies of previous reports. For research leaders to identify scientists and 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 lf 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 C~lifornia, Berkeley, CA 94720 University of California, 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, Honolulu, HI 96822 John Deere & Co., Moline, IL 61265 University of Illinois, Urbana, IL 61801 Indiana State Library, 140 N. Senate Ave., Indianapolis, IN 46204 Iowa State Universi ty, Ames, IA 50010 Enoch Pratt Free Library, 400 Cathedral St., Baltimore, MD 21201 USDA, National Agricultural Library, Publications Section, Beltsville, MD 20705 Department of AgronomY & Plant Genetics, University of Minnesota, St. Paul, MN 55108 Delta Branch Experiment Station, Stoneville, MS 38776 Linda Hall Library, 5109 Cherry St., Kansas City, MO 64110 C. Y. Thompson Library, University of Nebraska, Lincoln, NE 68503 Agricultural Library, Rutgers University, PO Box 231, New Brunswick, NJ 08903 Albuquerque Branch Library, Albuquerque, NM 87103 Albert R. Mann Library, Ithaca, NY 14850 New York State College of Agriculture, Agricultural Experiment Station, Ithaca, NY 14850 North Dakota State University, Fargo, NO 58102 Oregon State University, Corvall is, OR 97331 Pennsylvania State University, University Park, PA 16802 Steenbock Memorial Library, College of Agriculture & Life Sciences, Madison, WI 53706 Texas A&M University, College Station, TX 77843 Vermont Agricultural Experiment Station, Burlington, VT 05401 Commonwealth Scientific & Industrial Research Organization, Riverina Laboratory, Deni1iquin, N.S.W. Australia NSW Department of Agriculture, Sydney, N.S.W. Australia Cameron Library, University of Alberta, Edmonton, Alberta, T6G 2E1 Canada Central Experimental Farm, CA, Ottawa, Ontario, K2E GC7 Canada Canada Agriculture, Library Recording, Ottawa, Ontario K1A Oe5 Canada Station de Recherche, 2650 Boulevard Hochelaya, Ste-foy, Quebec, G1V 2J6 Canada Research Station, CA, University Campus, Saskatoon, Saskatchewan, S7N OX2 Canada University of Saskatchewan, Saskatoon, Saskatchewan, S7N OX2 Canada Research Station Library, Box 1030, Swift Current, Saskatchewan, S9H 3X2 Canada Bibliothek, Vyskumny Ustav Rast1innej Vyroby, 921 68 Piestany, Bratis1avska, Cesta 2966, CSSR-Czechos1ovakia Department of Applied Biology, University of Cambridge, Cambridge, England Department of Agricultural Science and Applied Biology, University of Cambridge, Cambridge, England Plant Breeding Institute Library, Maris Lane, Trumpington, Cambridge, England Grassland Research Institute, Hurley, Maidenhead, Berks, England Commonwealth Bureau of Pastures and Field Crops, Hurley, NR. Maidenhead, Berks, England Bureau of Plant Breeding & Genetics, School of Agriculture, University of Cambridge, Cambridge, England Bib1iotheque I.N.R.A., Station d'Amelioration des Plantes fourrageres, 86-600 Lusignan, France Station Centrale de Genetique et D'Amelioration des P1antes, Versailles, France Universitats-Bib1iothek, Abt. Zentralbib1iothek der Landbauwissenschraft, Box 264 Bonn 1, West Germany Library DeHaaf (Foundation for Agricultural Plant Breeding), P.O. Box 117, Wageningen-6104, The Netherlands George Forbes Memorial Library, Lincoln College, Canterbury, New Zealand Welsh Plant Breeding Station, Aberystwyth, Wales Lantbrukskogsko1an, U1tunabib1ioteket, S-750 07 Uppsala, Sweden Weibu11sho1m Plant Breeding Institute, Landskroma, Sweden Agricultural C~llege of Norway, AS-NLH, Norway Institut Za Op1emenjivanje Library, Maru1iceu Trg 5, 41000 Zagreb, Yugoslavia

ii TWENTY-SEVENTH ALFALFA IMPROVEMENT CONFERENCE Program Chairman--E. L. Sorensen Contents INTRODUCTION SPECIAL ADDRESSES Are We Paying Enough Attention to Soil Fertility?--Some Results with Potassium--Dale Smith 2 Forages, Food, and Energy--H. J. Hodgson. . • • • . • . . . . • . . • • • . . • • . • • • . . 14 AN ALFALFA PLANT JUICE, PROTEIN PRODUCTION SYSTEM Chairman--H. W. Ream Development of Farm-Scale Equipment for Alfalfa Fractionation--R. G. Koegel 21 Utilization of Pressed Alfalfa and Plant Juice Protein--N. A. Jorgensen •••••• 22 Utilization of Deproteinized Alfalfa Juice--M. Collins •..••..•••. • • 23 SEED PRODUCTION Chairman--D. E. Brown Alfalfa Seed Production Potentials for the 1980's--R. R. Kalton and D. E. Brown · 24 Lea fcutt i ng Bees for Fun and Profit--W. P. Stephen • • . . • • . • • • . . . • . • 27 NITROGEN FIXATION Chairman--L. 'R. Teuber

Ineffective Alfalfa Nodules: How and Why--C. P. Vance and L. E. B. Johnson .••• • • 28 Inheritance of Five Traits Conditioning Ineffective Nitrogen Fixation in Alfalfa-­ M. A. Peterson and D. K. Barnes ..••...•...•...•...••..• • 29 Competitive Ability of Rhizobium meliloti in Nodulation of Alfalfa' (Hedicago sativa L. )--G. Hardarson . • • . . . • . . • • • • . . • . • • • . . • . • 30 Field Survey of Acetylene Reduction Rates in Legumes Growing on Western Rangelands-- D. A. Johnson and M. D. Rumbaugh • . . • . . . . • . . • • . . . • .... · 31 Nitrogen Fixation of Alfalfa After Harvest •...••...•• • 32 Nitrogen Fixation of Alfalfa Measured by lsN Isotope Dilution-­ G. H. Heichel, D. K. Barnes, and C. P. Vance ..•.... • •• 33 DISEASES AND INSECTS Chairman--J. H. Graham Investigations on Distribution, Growth Rate, Resistance to, and Host Range of Race and 2 of Colletotrichum trifolii--R. E. ~Ielty, R. Y. Gurgis, and D. E. Rowe •... 34 The Occurrence of Race 2 of Colletotrichum trirolii in the Mid-Atlantic States-- S. A. Ostazeski and J. H. Elgin, Jr .•...•...•••...... ••••.• · .35- Effect of Downy Mildew Reaction of Selecting for Saponin Content in Alfalfa-- D. L. Stuteville and E. L. Sorensen •..•••..••...•••.•••.• • 36 Effect of Spring Black Stem on Alfalfa Forage Yield in the Greenhouse and Possible Selection Methodology--E. H. Hijano and F. I. Frosheiser .•.••....••.• 37 Surface Sterilization of Alfalfa Seed and Alfalfa Plant Tissues With Chlorine Gas-­ B. D. Thyr, B. J. Hartman, N. P. Maxon, and S. A. Fazal Farook .•••..• 38 Consumption, Assimilation, and Conversion of 15 Forage Legumes by Lepidopteran Larvae in Wisconsin--J. M. Scriber ..•.•...•..•••.••.••. • 39 '- ALFALFA MANAGEMENT Chairman--J. L. Caddel The Effects of Seeding Rates on Stand Longevity, Stand Count, Stem Number and Forage Yield of Alfalfa--B. J. Hartman, R. N. Peaden, B. D. Thyr, and O. J. Hunt...... 40 Effect of Nematocides and Fungicides on Legume Establ ishme'nt in Northern Minnesota-- C. C. Sheaffer, D. L. Rabas, D. H. MacDonald, and F. I. Frosheiser . . . . • • . • • • . . 41 Effects of Three Harvest Schedules on Forage Yield, Quality, and Persistence of Six Alfalfa CUltivars--I. T. Carlson and I. D. C. Obierika • • . . . • • . • . • • • . 42 Fertility and Management Practices for a 10-Ton Yield in Michigan--M. B. Tesar. • 43 La~e Autumn Harvest of Third Crop Alfalfa Can Allow Long Stand Persistence 1n the North--G. C. Marten • • ...... • • • . • . • ...... 44 Reproduction of Alfalfa in a Dryland Pasture--M. D. Rumbaugh . . . . . 45 Alfalfa Management Research in Nevada--E. H. Jensen • • • ...... • 46 Pennsylvania's Alfalfa Growers Program--A Field Study--J. E. Baylor . • 47 Forage Yields from Different Patterns of Initial Stands--J. W. Miller • 48

iii TRICHOMES ON Hedicago SPECIES Cnairman--E. L. Sorensen Glandular Secretory System of Annual and Perennial Hedicago Species-- G. L. Krei tner and E. L. Sorensen . . . . • • . • • . . • . • . • ...... • · . 50 Resistance to Alfalfa Weevil and Potato Leafhopper Increased by Glandular and Simple Hairs--E. K. Horber. E. L. Sorensen. and K. J. R. Johnson ...... 51 The Chemical Identification of the Glandular Hair Exudate from Hedicago scutellata-­ D. r. Triebe, C. E. Meloan, and E. L. Sorensen ...... • · 52 Transf~r of Glandular Hairs from Diploid Hedicago prostrata to Tetraploid H. sativa-­ E. L. Sorensen, N. Sangduen, and G. H. Liang .....•.•...... •..••. · 53 ALFALFA BREEDING Cnairman--D. A. Miller Factors Affecting Yield and Quality of Alfalfa Sprouts--O. B. Hesterman and L. R. Teuber .• 54 An Overview of Legume, Pasture Bloat Research at Saskatoon--R. E. Howarth, G. L. Lees, and B. P. Goplen ...... • ...... • • . . . • . . • 55 Selection for Phosphorus and Lignin Content in Alfalfa--R. R. Hill, Jr. •..•.. 56 Changes in tne Cold Hardiness of Alfalfa lHedicago falcata) During Five Consecutive Winters in Northern Alberta--J. S. McKenzie • ...... • ...... • . . 57 Use of Strain Crosses in Breeding Multiple Pest Kesistant Alfalfa--J. H. Elgin, Jr. . • 58..-0 Field Selection for Phytophthora Resistance in Aphid Resistant Alfalfa Populations-- W. R. Kehr, D. K. Barnes, F. 1. Frosheiser, and G. R. Manglitz • . • • • . • • . • •. 59 Self- and Cross-Fertility in Alfalfa Populations Before and After Selection for Pest Resistance--J. A. Rodriguez and W. R. Kehr • ...... • ...... • 60 Enzyme Electrophoresis as an Aid for Alfalfa Breeding--C. F. Quiros ...... • . . 61 Variation in Morphological Characteristics Among Plants of Alfalfa Cultivar Saranac AR-- F. W. Snyder, G. E. Carlson, J. H. Elgin, Jr., and N. J. Chatterton . . . . • • . . .• • •. 62 - POSTER SESSION ABSTRACTS Harvest and N Fertilizer Effects on Alfalfa Root Nodule Enzymes of Ammonia Assimilation-- R. G. Groat and C. P. Vance ...... • • . . • . . . • • ...... • • • . • • 64 Description and Inheritance of Root Traits in Alfalfa--M. A. Brick and D. K. Barnes · 66 Insights After One Year of Fall Dormancy Determination at Several Locations-- L. R. Teuber, B. J. Hartman, and W. L. Green ....•...... •... · 67 A Pink Pea Aphid Biotype on Alfalfa--J. L. Kugler •••.....••.... · • 68 ABSTRACTS OF RESEARCH NOT PRESENTED AT CONFERENCE Fall Growth of Alfalfa Used in Wisconsin To Identify Strains Since 1918--0. Smith . . . . . 69 Combining Ability in Alfalfa Combinations Made with Male Steri1ity--B. Nagy ....••••..• 70 Evaluation of Pasture Alfalfa Hybrids in Grazing and Grazing Simulation-- J. M. Piskovatski and G. V. Stepanova ..•••.••...... • . . • . . . • . 70 Results of Breeding for Resistance Against Verticillium alboatrum lRke. et Berth) with Alfalfa lHedicago media Martyn.) in The German Democratic Republic--R. Steuckardt 72 New Data on the Amount of Se1fing in Alfalfa--F. Lorenzetti, A. Panella, and F. Veronesi 74 The Analysis of the Growth Curve of Alfalfa lHedicago satifa L.)-- M. V. Benesra R. and T. Oropeza • . . • . • . • . . • • • . . . • . . . . . • • . . • • • • • • 76 Relationship Between Growth Habit and Some Factors Affecting Alfalfa Seed Yield in Hungary-- S. Manninger, K. Mann1nger, Cs. Erd&lyi, J. Bug10s, L. Martinovich, and A. Dobrovo1szky .•.. 79 Saponin Content and Its Relationship to Variety, Temp'erature, and Field Resistance to Fusarium and Verticillium Fungi in A1falfa--J. Buglos, I. B6csa,/~, Manninger, and S. Manninger .•... 80 Ten Years Research Work on Hybrid Alfalfa in Hungary--Z. BOjtos ...' . • . . • . . . 81 Effect of Seasonal Variations and Cutting Intervals on Alfalfa Proteins in Egypt-- A. M. Rammah and A. S. Hamza •..•...•..•...... ••••••. . 82 Pathological Studies on the Fungi Associated with Diseased Clover Plants in Egypt-- Z. M. E1-Tobshy, A. M. Rammah, M. A. Abdel-sattar, and M. A. Baraka . . • . . • • . . 83 Pathological Effect of Some Egyptian Fungal Isolates on American Alfalfa Varieties-- Y. El-HyatemY, A. M. Rammah, and H. I. Seif El-Nasr . • • . • • . . . • • . . • . 83 Effect of Two Root Rot Diseases on Alfalfa (Hedicago sativa L.) Grown in Different Egyptian Soils--A. M. Rammah, H. Gama1 E1-Din, and H. I. Seif El-Nasr • . • . . 84 A New Pathogen Non-Sporulating BasidiomYcetes Fungus Causing Root Rot of Alfalfa Plants in Egypt--H. I. Seif E1-Nasar, A. M. Rammah, and H. Gamal El-Din .•. . • • • . •. 84 BUSINESS MEETING

Committee on Preservation of Germp1as~-W. R. Kehr, Chairman •.••.• 85 Committee on Alfalfa for Dryland Grazing--A. C. Wilton, Chairman •••.. . •• 87 Committee on Available Breeding Lines of Alfalfa--R. N. Peaden, Chairman • 88 Committee on Variety Certification--D. E. Brown, Chairman .•..••• 90 Committee on Standard Tests for Characterizing Disease and Insect Resistance of Alfalfa Cu1tivars--J. H. Elgin, Jr., Chairman.. • •.••. .93- Nominations Committee Report--E. L. Sorensen, Chairman ..••. 94 Resolution Committee Report--J. W. Miller, Chairman •.. • 96 Plans for 1982 Natlona1 Alfalfa Improvement Conference .• • 95 Secretary's Report--D. K. Barnes .••..•••.•••..•...••.. . • 96 Alfalfa S~ientists on Alfalfa Improvement Conference Mailing List • 98 Mailing List Questionnaire. • • . . • • . . . • •.....• • 100 ;v Introduction The 27th National Alfalfa Improvement Conference (NAIC) met at the Sheraton Inn, Madison, Wisconsin. The conference was opened by Dr. E. L. Sorensen, chairman of the NAIC. Dr. L. M. Walsh, Dean, College of Agri­ cultural and Life Sciences, University of ~Jisconsin, welcomed the parttci­ pants and briefly described the importance of alfalfa to Midwest agriculture. He mentioned that the Wisconsin average forage yield for alfalfa had been slow to increase. He attributed some of this to the type of land that was planted to alfalfa. According to ~Jalsh, alfalfa will be a key factor in in­ creasing U.S. and world food production. Increased fertility levels will be an important future input to alfalfa production. Marketing and utiliza­ tion will need to be improved so that alfalfa can go into commodity markets much like grains. Problems in soil productivity, i.e., high erosion rates, are increasing due to maximum production problems of row crops. Therefore, there will be an increasing need for forage species, primarily alfalfa to protect soil resources. This will require agriculture to have a greater animal base. The conference included approximately two days of paper presentations and poster sessions. Two special addresses were presented. They were "Are we paying enough attention to soil fertility?--Some results with potassium" by Dr. Dale Smith and "Forages, food, andenergy" by Dr. Harlow J. Hodgson. Both Dr. Smith and Dr. Hodgson are internationally recognized forage scientists who have been associated with the University of Wisconsin. The third day of the conference included a field trip by bus to the Univer­ sity of Wisconsin campus, USDA Dairy-Forage Laboratory, and the Arlin~ton Experimental farm, followed by an evening picnic. This report contains the two special addresses, abstracts of research studies reported at the conference, volunteer abstracts and brief articles submitted by scientists not attending the conference, committee reports, business transacted, and information on distribution of conference reports and membership.

Presenters and their organizations are responsible for the information they have contributed to this report and do not necessarily represent the view of the U.S. Department of Agriculture. Authors should be consulted by those who wish to reproduce the reports, wholly or in part.

Mention of companies or commercial products does not imply recommenda­ tion or endorsement by the U.S. Department of Agriculture over others not mentioned.

Members of the executive committee of the 27th NAIC included: E. L. Sorensen, chairman, ~1anhattan, KS; I. T. Carlson, Ames, IA; J. H. Elgin, Jr., B~ltsville, MD; M. K. Miller, Fresno, CA; D. E. Brown, Caldwell, ID; E. T.· Blngham, Madison, WI; and D. K. Barnes, permanent secretary, St. Paul, MN. Copies of this report are available from D. K. Barnes, USDA-SEA-AR, Depart­ ment of Agronomy, University of Minnesota, St. Paul, MN 55108. Are We Paying Enough Attention to Soil Fertility? Some Results with Potassium I

Dale Smith Professor Emeritus of Agronomy2 University of Wisconsin, Madison I am very pleased to have been invited to speak at this conference on the fertilization of alfalfa. This is a subject that has not received much atten­ tion at the conference meetings over the years. Yet, an adequate level of soil nutrients is a primary consideration in obtaining vigorous seedings, maximum productivity, persistence, and normal physiological activity within the alfalfa plant.

I would like to present the results of some K-topdressing studies conducted at Wisconsin between 1970 and 1975. These studies suggest that we are not using enough K for maximum production with today's high-yielding and persistent cu1tivars that are being harvested frequently for quality herbage. Our present cultivars and cutting practices postdate many of the soil fertility trials upon which soil fertilization recommendations are based.

The K-topdressing studies I will present were aided by the preparation of four acres of low fertility soil on the Wisconsin Agrico Exp. Station at Arlington (about 25 miles north of Hadison). The soil is a Plano silt loam which orig­ inated under prairie conditions on a 36 to 48 inches of loess over calcareous loam till. The soil area ,~as cropped for 8 years (1961-68) alternately with corn and alfalfa without fertilization to provide a low fertility area for K studies. Field Studies With Increasing K-topdressing Rates.

Ranger alfalfa was established during the spring of 1969 on the low-fertility Plano silt loam soil noted above. Eight levels of K were established on the alfalfa stand. KCl (0-0-60) fertilizer was applied in the autumn of 1969 (seeding year) at 0, 50, 100, 200, 400, 600, 800, and 1,000 lbs/A of K. These same rates were applied again in the autumn of 1970. All plots were fertil­ ized with 0-46-0 so that phosphorus was not limiting. The alfalfa was har­ vested using two different cutting schedules: (1) three times annually at first flower and (2) three times plus a cut in mid-October (four cuts) during 3 years, 1970-72.

Highest herbage yields were produced during the 3-year period \~here 600 lbs/A of K as KCI \~ere topdressed before the first and second harvest years (Table 1). Overall average yields increased significantly with each increment

lThe author acknowledges the advice and assistance of L.A. Peterson, R.D. Powell, R.S. Rominger, and R.M. Soberalske during the conduct of the Wisconsin studies and A. K. Dobren"z at Ari zona. 2Current1y Adjunct Professor of Plant Sciences, University of Arizona, Tucson.

2 Table l.--Average annual yields of oven-dry hay in tons/acre from Ranger alfalfa at Arlington Wis., during 3 years, 1970-72. (Adapted from Smi th, 1975) i

Pounds/acre of K applied in autumn of 1969 Cuttings and again in 19702 LSD, Annually 0 50 100 200 400 600 800 1000 0.05

3 3.00 3.58 3.81 4.00 4.31 4.48 4.38 4.25 0.19

4 (3 plus Oct. IS) 2.77 3.48 3.66 4.03 4.17 4.34 4.24 4.23 .19

Average3 2.88 3.53 3.73 4.01 4.24 4.41 4.31 4.24 .10

lInitially, the soil contained 127, 117, 129, 175, 198, and 204 1bs/A of exchangeable K at 6-inch depths from the soil surface (to 36 inches). The annual release rate of K from the soil was about 57 lbs/A. 2App1ied as KCl fertilizer. 3Eight replications.

of K to 600 lbs/ A. They then decreased with the t\vO higher K rates, and yield at 1,000 lbs/A was significantly lower than that at 600 lbs/A.

Percentage of K in the herbage increased with each increment of added K during each year (Table 2). Percentage of herbage K with the 600 lbs/A rate of K, where maximum herbage yields were obtained, was bet\veen 2.5 and 3.2% each year. Percentage of herbage K for this treatment averaged 2 0 8% for 3-harvest years and probably indicated the approximate K level needed in the total herbage harvested at first flower to maintain maximum growth and productivity under the conditions of this experiment.

Total amount of K removed with the herbage each year also increased with each higher rate of topdressed K (Table 2). Removal of K in herbage at the 600 lbs/A rate averaged 255 lbs/A annually for the three harvest years.

The reduction in herbage yields at K rates hi~her than 600 lbs/A (Tables 1 and 2) was no doubt the result of Cl- added with the KCl fertilizer (Smith and Peterson, 1975; Rominger et alo, 1977; Smith and Struckmeyer, 1977). Weakened and damaged plants were noted in the spring of the second harvest year (1971) where 800 and 1,000 lbs/A of K as KCl had been topdressed during the previous two autumns. Percentages of herbage-Cl- in the first and second harvests of

1971 are shown in Table 3 0 In a previous growth chamber trial (Smith, 1971), it \Vas found that total plant yields of alfalfa increased with each additional increase in K as K2S04 but eventually decreased at high rates of KCl. Simi­ lar results also were obtained in a field trial conducted on the Hill Farm at Madison.

3 Table 2. -- Annual herbage yields, herbage K percentage, and amount of K removed by alfalfa harvested three times annually during \ three harvest years. (Adapted from Smith, 1975) 1

K Herbage yields Herbage K Herbage K Applied2 1970 1971 1972 1970 1971 1972 1970 1972 1972

Ibs/A ----tons/acre------%------lbs/A------0 2.58 3.19 3.22 1.0 0.9 0.9 53 60 61 50 3.21 3.99 3.53 1.2 1.2 1.0 75 93 68

100 3.45 4.26 3.71 / 1.5 1.6 1.1 102 132 85

200 3.45 4.43 4.11 1.9 1.9 1.3 129 169 107

400 3.77 4.B4 4.31 2.3 2.6 2.1 174 253 181

600 3.93 5.09 4.41 2.5 3.2 2.8 195 324 245

BOO 3.B7 4.B5 4.42 2.7 3.3 3.4 210 3lB 304

1000 3.75 4.61 4.38 2.B 3.6 3.8 212 330 334

LSD,O.OS .33 .40 .31 .1 •. 2 .3 20 24 22

~Results were similar with four harvests annually. Applied autumn of 1969 and of 1970 as KCl fertilizer.

Field Studies Comparing KCl and K2S04 Fertilizers

A 3-year-old stand of Vernal alfalfa growing on low fertility Dodge silt loam soil was topdressed during 1972 and 1973 with zero, 400, BOO, 1200, and 1600 lbsK/A/year as either KCl or K2S04• The top 6 inches of soil showed 110 lbs/A of exchangeable K, 68 lbs/A of available P, 5 lbs/A of 8°4-5, no Cl-, and had a pH of 6.9.

Potassium was topdressed each spring and four harvests were taken in both 1972 and 1973 \~ith the last one on September 4. Herbage yields increased \~i th 400 lbsK/A/year of KCl and K2S04 (Figure 1) but at BOO lbsK/A/year'or higher, yields decreased with KCl. In contrast, high yields were maintained at high rates ,of K2S04• Weakened and damaged plants were found at the high rates of KCl. Presumably, plant damage and killing occurred because of toxic levels of Cl- in the tissues. As higher fertilization rates of KCl are recommended on alfalfa there is a need to establish the Cl- percentage that negates any further yield increase from additional K. There also is a need to know more about toxic

4 Tab Ie 3. -.- ,'concentration of Cl- in herbage of the first (June 3) and second (July 8) harvests of 1971 and in the soil at date of second harvest where different rates of KCl were topdressed (Smith and Peterson, 1975)

Pounds/acre of Cl- applied during autumns of 1969 and of 1970 Parameters o 90 181 543 90S

Percent Cl- in Herbage Herbage harvest: Firstl 0.04 0.86 1.07 1.50 1.90 Second2 .07 .84 .96 1.31 lD67 PPM Cl- in Soil Soil depth, inches 0-3 0 0 8 74 157 3 - 6 0 0 21 128 253 6 - 9 0 2 28 140 268 9 -12 0 0 17 75 175 12 -18 0 1 1 32 93 18 -24 2 0 0 23 28 24 -30 0 0 3 48 48

ILSD 0.05 was 0.21. 2LSD 0.05 was 0.12.

levels of Cl- and the toxic effects of Cl- in the plant. Alfalfa shoots damaged by Cl- show leaflets that are yellowed, thickened, and deformed, with the internal tissue badly disrupted (Smith and Struckmeyer, 1977). However, many young shoots are killed by Cl- before they elongate very far, so that Cl­ concentration at bud or first flower does not provide an indication of toxic concentration. An alternative to fertilizing with KC1 is to use K2S04, or to apply part of the K as K2S04 when high rates are to be applied.

Herbage Composition with Increasing Rates of K

Chemical analyses of the total herbage produced in the third harvest year of the K-rate study (Table 1) are shown in Table 4. Concentration of Mn, as well as K, increased as K topdressing rate increased, while concentrations of N, P, S, Ca, Mg, Na, Cu, Zn, and B decreased. There was no effect on in vitro digestible dry.matter, Fe, or Al concentrations. The lowered concentrations of elements in herbage with K fertilization can influence the sufficiency of other elements needed for maximum growth and productivity. When herbage-K is made adequate by topdressing, concentrations of other elements may be decreased to deficiency levels. In this study, percentage of S was at suffi­ ciency level (0.3%) in the control herbage but was below sufficiency (0.2%) at the 600 lbs/A rate, where maximum yields were obtained. Thus, a complete tissue analysis is needed when high K rates are applied to be certain that other critical elements are still above sufficiency levels in the tissue and are not limiting production.

5 Table 4.-- Chemical composition of the ·tota1 herbage dry matter produced during the third (final) cutting year after topdressing the stands with different rates of KC1 (Smith, 1975) 1

Consti- Pounds/acre of K applied, autumn of 1969 and 1970 LSD, tuent 0 50 100 200 400 600 800 1000 0.05 % TNC2 5.6 5.3 5.2 5.4 5.0 4.6 4.4 4.3 0.3 IVDDM3 64.8 64.8 64.1 64.7 6400 64.3 65.1 66.0 ns N 3.74 3.77 3.65 3.55 3.46 3.36 3.26 3.27 .09 P .30 .31 .30 .29 .28 .26 •. 26 .26 .01 K .89 .93 1.15 1032 2.05 2.73 3.36 3.68 .18 S 030 029 .26 .24 .23 .22 .22 .22 .02 Ca 1.70 1.73 1.69 1.62 1.52 1.36 1.24 1.21 .06 Mg 063 .64 .62 .55 .47 .38 .33 .31 .03 Na .16 .14 .13 .12 .08 .05 .03 .02 .01 ppm

Cu 14 13 13 12 12 11 11 11 1 Fe 139 166 152 153 152 144 147 149 ns Zn 26 26 26 25 25 25 24 25 1 B 25 25 26 25 25 23 23 23 1.5 f.fn 44 47 47 46 50 51 54 55 2.7 Al 138 164 151 157 150 141 142 140 ns 1Calculated as 8 replications. 2 Total nons tructural carbohydrates 0 3In vitro digestible dry matter. , 0---0 5.0 , _-4'

,...Q) 4.5 Figure 1. Average annual herbage u yi.e1ds for two harvests ...... CIS years with increasing 0) s:: rates of K applied annually o as KCl and K2S04. LSD at E-c 4.0 0.(l5 was 0.55. (Adapted from Rominger et al., 1976) •

3.5~'---~----~--~----~- o 400 800 1200 1600

Pound~/acre K applied annually

6 Final Stands from the K-rate Study

Visual stand estimates made in June 1973 at the completion of the K-rate study (Tables 1 and 2) showed the cumulative effects of three treatment years (1970- 72). Stand percentages increased steadily up to 400 or 600 lbs/A rate of K (Table 5), with little difference at the higher K rates. Stands at 400 to 1000 lbsK/A with 3 cuts annually were excellent, ranging from 92 to 95% of a full stand, while stands wth 4 cuts (3 plus Oct. 15) annually were only slightly lower (81 to 89%). Stand percentages were lower where 4 rather than 3 cuts had been harvested annually during the three previous years. However, reductions in the stand due to 4 as compared with 3 cuts annually were less than 13% at K rates of 400 lbs/A or higher, while stand reductions amounted to 22, 30, 45, and 49% at the 200, 100, SO, and zero rates of K, respectively. Thus, mid-October cutting with the 4-cut schedule thinned stands, especially at the low K rates. Residual herbage yields followed these same trends.

Table 5.-- Remaining stands of Ranger alfalfa in spring of fourth year after 3 years (1970-72) of harvest at Arlington, Wis., with annual applications of KCl during the first 2 of 3 years (Adapted from Smith, 1975)

~2 K Applied,l Ground cover, 0 Reduction with lbs/A 3 cuts 4 cuts 4 cuts, %

0 47 24 49 50 64 35 45 100 79 55 30 200 85 66 22 400 93 81 13 600 95 84 12 800 92 89 3 1000 93 86 8

LSD 0.05 12 18 IThese amounts applied autumns of 1969 and 1970. 2Based on a full stand at 100%.

Winter Survival of Stands with Three Rates of P and K

Vernal alfalfa was seeded in the spring of 1972 on a low K Plano silt loam soil area at the Arlington Exp. Farm. The top 6 inches of soil showed 120 lbs/A of exchangeable K, 51 lbs/A of available P, and a pH of 6.7.

Potassium and P were topdressed during autumn of the seeding year. The rates were zero, 200, and 600 lbs/A of K (as KCl) in all combinations with zero,

7 20, and 40 1bs/A of P (as concentrated superphosphate). No additional P was added, but the K rates were applied each autumn. Other soil elements were sufficient for growing alfalfa, including Sand B. The plots were harvested 3 times at first flower in 1973 and in 1974. Fertilization with P had no significant influence on hay yields, but yields were increased significantly with K. In the first harvest year, maximum hay yield was obtained with the first increment of K (200 1bs/A). In the second harvest year, yields were increased signficantly with each increase in K applied and highest yield was obtained with 600 1bs/A of K applied annually.

Alfalfa stands were injured badly during the winter of 1974-75 because of a lack of snow cover. As a result, only the first harvest was taken in 1975 at first flower in June. Stand estimates were made on the recovery growth. Again, fertilization with P had no significant influence on residual yields or stands. The influence of K fertilization was dramatic. Alfalfa stands with no K fertilization were killed completely (Table 6). Residual yields and stands increased with each increase in K applied.

Table 6.-- Residual herbage yields harvested at first flower in June of the third harvest year (1975) and final stand estimates (Adapted from Smith and.Powell, 1979) 1

Applied Applied Herbage Stand K P Yield Remaining2

Lbs/A/Yr Seeding Tons/A % Yr.

0 0 0 0 0 20 0 0 0 40 0 0 Avg. 0 0 200 0 0.15 14 200 20 .74 21 200 40 .71 22 Avg. 0.53 19 600 0 .74 36 600 20 1.09 38 600 40 1.20 38 Avg. 1.01 37 LSD, 0.05 .71 21 .10 .59 17

lThere were no signficant differences due to P, differences were due to Ko 2Based on a full stand as 100%.

8 Absorption of K from Different Soil Depths An experiment was initiated in the spring of 1971 to determine the uptake of K and S04 by a 2-year-old stand of Ranger alfalfa from different depths in a low K Plano silt loam soil profile at the Arlington Expo Farm (Peterson and Smith, 1973). An injection method was used to place a solution of K2S04 at depths of 3, 9, 15, 21, 27, and 33-inches below the soil surface. A control and a surface broadcast application of K2S04 also were included as treatments. Potassium sulfate was applied at 200 lbs/A of K and 82 lbs/A of S in April 1971. Treatment areas were approximately 9 sq. ft. Three cuttings were taken at first flower during 1971, and the herbage was analyzed for yield and concentrations of K and So

Alfalfa recovered 41, 29, 19, 16, 10, 15, and 11% of the added K from the surface, 3, 9, 15, 21, 27, and 33-inch soil depths, respectively (Table 7). No major differences were observed in S concentration of the tissue, since the Plano silt loam soil contained sufficient S for alfalfa.

Table 7.--Percentage of K in alfalfa herbage in the first-flower cutting in June 1971 as influenced by depth of soil placement of 200 lbs/K at K2S04 in April, and the proportion of the K applied that was removed from the soil with three harvests (Adapted from Peterson and Smith, 1973)

Depth of K placement K in first- Proportion of applied K from soil surface cut herbage removed in 3 cuttings

inches % %

(Control) 1.07 surface 2.17 41 3 1.65 29 9 1.45 19 15 1.22 16 21 1.16 10 27 1.20 15 33 1.14 11

LSD, 0 0 05% .26

These data show that alfalfa absorbed K most heavily from the soil surface, and that very little was removed from the subsoil even with an extensive root systemo This indicates fuat mixing K into the soil surface is not necessary and that maximum efficiency can be obtained by topdressing. Because of surface feeding, increased surface rootings in new alfalfa varieties should be an objective in alfalfa breedingo This would be particularly important in northern areas where less K is obtained from the soil by plants because of cool temperature conditions (Smith, 1971).

9 Let's Do More Soil and Tissue Testing I ask the question "are we paying enough attention to the soil and its nutri­ ent levels?" As breeding, management, and physiology specialists, I know we give full attention to selecting the proper germplasm, cutting schedule, height of cutting, and to insect and disease control. But, how many of us are routinely testing the soil and/or tissue for elemental levels. If the soil cannot provide the amount of each nutrient that is needed by the alfalfa plant for maximum growth, we may well obtain biased answers from our research.

We should adequately test the soil before establishing a breeding nursery or management trial, and not just for the usual N, P, and K, but for other ele­ ments as well. Since the soil test usually is less precise than a tissue test, the herbage should be tested soon after the stand has been established. It- is the plant that can best tell us what is available from the soil. An example of the information obtained from a soil and tissue test is shown in Table 8. The soil test indicated that the soil had adequate amounts of K and S but that it was low in P and borderline in B. However, the tissue test showed that the K .and S concentrations were low, even though the soil test indicated that they were sufficient. In contrast, tissue P concentration was sufficient, even though the soil test showed P to be low. Both the soil and tissue tests indicated that B was borderline. The tissue test also gave a broader elemental profile and provided information we would not have known from the soil test alone: that Mg concentration was very low and that Zn was border1ine o

Table 8.--Elemental levels in the herbage of bud-stage alfalfa and soil from an alfalfa field near Tucson, Arizona, sampled in 1979 (Unpublished data, Univ. of Arizona)

l ... Soi1 Tissue Lab. Leve1 Lab. Sufficiency3 Elements test Needed 2 test needed

P 13 1bs/A + 50 lbs/A 0.33% +0.30% K 750 +400 2.58 +2.80 Ca 1.44 + .65 Mg .15 + .35 S 224 + 40 .23 + .30

B 2.1 + 3 30 ppm +30 ppm Zn 21 +20 Cu 19 + 7 Mn 51 +25 Fe 326 +30 ISoil tested pH 8.0. 2Based on Wisconsin recommendations. 3~finimum concentrations at first flower needed for maximum growth based on Wisconsin and Illinois Data (Schulte, 1977; Me1sted et al., 1969).

10 Today, tissue samples can be analyzed accurately at several different labor­ atories by spectrometry with a minimum of effort and expense. As a result, we can quickly determine the elemental status of our alf~lfa nurseries and plot trials. Tissue tests made at first flower from nine alfalfa fields in the Phoenix area of Arizona are shown in Table 9. These tests indicated that the herbage in all nine fields was below sufficiency level in both P and Mg, that two fields were low in K, and that the two were borderline in Zn. Since these results were from the total herbage (above a 2.5 to 3.0-inch stubble), the results also can be used as feed analysis data.

I hope that both soil and tissue testing are a routine procedure in your research 0 It is quite discouraging to read reports and journal papers that merely say that "the research was conducted with high soil fertility" with no elemental levels given, or that only a routine soil test was made for pH, N, P, and K, with no tests made for levels of Ca, S, Mg, B, Zn, Cu, Mn, Fe, etc. A deficiency of only one of these elements could easily bias research results, especially in nitrogen-fixation, photosynthetic, enzyme, and other basic physiological studies.

Table 9. -- Elemental analysis of the herbage of bud-stage alfalfa from nine fields near Phoenix, Arizona, sampled in 1979 (Unpub- lished data, Univ. of Arizona)

Alfalfa P K Ca Mg S Mn Fe Cu Zn B fields % - -- ppm - ...... -

A 0.24 2.98 1.79 0.28 0.44 33 127 20 27 43 B .23 2.60 1.76 .29 .43 27 107 20 27 40 C .25 3.20 1.93 .28 .40 28 122 17 25 48 D .25 3.22 1087 .27 .38 38 117 19 27 49 E .23 3.24 1.95 .25 .42 34 132 19 24 47 F .23 3.54 1.76 .26 .44 34 129 21 24 44 G .18 3.54 1.77 .23 .48 30 100 20 20 38 H .25 3.60 1.75 .21 .45 37 156 22 26 44 I .21 2.56 1.96 .19 .32 36 181 25 19 54

Sufficiency1 0.30 2.80 0.65 0.35 0030 25 30 7 20 30

1 , . . M1n1mum concentrat1ons at first-flower needed for maximum growth based on Wisconsin and Illinois data (Schulte, 1977; Melsted et a1., 1969)0

11 CONCLUSIONS

1. Amount of fertilizer (K) needed for new cultivars or new intensive harvest schedules may be higher than current recommendations that are often based on old varieties or less intensive harvest schedules. 2. Potassium chloride (KCI) is the main carrier of K used throughout the world. As we recommend higher fertilization rates of KCI on alfalfa, we need to know more about the toxic levels of CI- and the toxic effects of CI- in alfalfa tissue. For example, we need to establish the CI- percent­ age that negates any further yield increase from additional K as KCI.

3. The use of K2S04 is suggested in small pot studies in the greenhouse and growth chamber in order to avoid any possible CI- injury that may occur with high rates of KCI. 4. Fertilization with K influences herbage composition. Herbage-K percentage increased with increasing K applications to the soil, but other elements may decrease by dilution. In the study presented, percentage S decreased to a deficient level in the tissue at the K rate that gave the highest herbage yields. s. Alfalfa cut either three or four times annually maintain~d excellent stands at high levels of K. Stand persistence decreased at low levels of K, especially with an autumn harvest (4 cuts). 6. The deep tap root of alfalfa probably is important only for the absorption of water from the subsoil as minerals (at least K) are absorbed mostly by roots near the soil surface. 7. Increased surface rooting in new alfalfa varieties should be an objective in alfalfa breeding, since these roots absorb most of the minerals (K)o 8. Both soil and tissue testing should be routine procedures to assure no elemental deficiences in research studies. These tests should include more than just a test for N, P, and K, and should include other elements important to the maximum growth of alfalfa, ie. Ca, S, Mg, B, Zn, Cu, Mn, Fe, etc.

12 LITERATURE CITED

~1elsted, S. W., H. L. Motto, and T. R. Peck. 1969 0 Critical plant nutrient composition values useful in interpreting plant analysis data. Agron. J. 61: 17-20.

Peterson, L. A., and Dale Smith. 1973. Recovery of K2S04 by alfalfa after placement at different depths in a low fertility s01l. Agron. J. 65: 769-772. Rominger, R. S., Dale Smith, and L. A. Peterson. 1976. Yield and chemical composition of alfalfa as influenced by high rates of K topdressed as KCl and K2S04. Agrono J. 68: 573-577. Rominger, R. S., Dale Smith, and L. A. Peterson. 1977. Influence of high rates of topdressed KCI and K2S04 on recovery of K, Cl, and S04-S by alfalfa and residual amount remaining in the soil. Commun. Soil Sci. Plant Anal. 8(6): 489-507. Smith, Dale. 1971. Levels and sources of potassium for alfalfa as influenced by temperature. Agron. J. 63: 497-500.

Smith, Daleo 1975 0 Effects of potassium topdressing a low fertility silt loam soil on alfalfa herbage yields and composition and on soil K values. Agron. J. 67: 60-64. Smith, Dale, and L. A. Peterson. 1975. Chlorine concentrations in alfalfa herbage and soil with KCl topdressing of a low fertility silt loam soilo Commun. Soil Sci. Plant Anal. 6(5): 521-523.

Smith, Dale, and R. D. Powell. 1979. Yield of alfalfa as influenced by levels of P and K fertilization. Commun. Soil Sci. Plant Anal. 10(3)" 531-543.

Smith, Dale, and B. E. Struckmeyer. 1977. Effects of high levels of chlorine in alfalfa shoots. Can. J. Plant Sci. 57: 293-296. Schulte, E. E. 1977. Alfalfa fertilization. Univ. Wisconsin-Ext. Fact Sheet. A2448.

13 Forages, Food, and Energy

Harlow J. Hodgson University of Wisconsin ~~dison, Wisconsin

The forage-ruminant complex is one of the major food-production systems of this and many other countries (Hodgson, 1976 a,b, 1978; Wedin et al., 1975). This system involves the transformation of radiant energy of sunlight into the chemical energy of plant proteins, carbohydrates, fats and other compounds found in the herbage of forage species. It further involves the conversion, by ruminant animals, of this chemical energy into that in similar compounds of foods of animal origin.

We maximize the transformation of solar energy by optimizing the environment in which we grow,forages and by using cultivars with improved genetic poten­ tial. These involve the application of cultural energy, much of it fossil energy based. The rate of transformation of solar energy is generally in pro­ portion to cultural energy inputs.

In contrast, the rate of conversion of the chemical energy in plants into foods of animal origin is dependent upon quality factors of the consumed for­ age. Total animal product per hectare mayor may not be highly correlated with forage dry matter production per hectare.

When forage productioIl and utilization by ruminant livestock is done well, we have a highly efficient and economic system for the conversion of solar energy to human food. This can be' accomplished on land not well suited to the pro­ duction of crops directly consumable as food by man. However, we do use a considerable portion of our arable land for forage and ruminant livestock production.

The principal use of forage is ruminant livestock feed. There are other potential uses--l) the production of protein feeds for monogastric animals, including man, and 2) as a source of cellulose for the production of ethanol and perhaps other liquid fuels. Breakthroughs in the conversion of cellulose to ethanol could result in a very large new market for forages. However, my main objective today is to elucidate the role of forages in food production by ruminant livestock.

Present contributions to the food supply: Americans consume about 645 kg of food per capita per year. About 42 percent of this is food of animal origin. About 212 kg, or about one-third of our food supply, is provided by ruminants.

Foods of ruminant origin are important sources of protein, energy, and other nutrients and minerals. About 23 percent of our total energy consumption and 45 percent of our protein supply comes from beef and dairy products. Each provides essentially the same amounts in spite of the fact that there are about four times as many beef cows as dairy cows. These animals provide about one-third of our fat supply, and they are highly important sources of

14 phosphorus and calcium. This contribution is greater than that from flour and cereal products, dry beans, soya flour, and nuts.

Meat and dairy products are foods of high nutritional quality. They comprise two of the four major food groups. Almost every set of dietary recommenda­ tions includes liberal amounts of these foods. Thus, foods of ruminant origin are highly important to us. Nearly all of the world's people desire more of these products in their diets. They are foods of high choice.

The ruminant feed-base: Forages provide a large portion of the feed consumed by ruminant animals. About 80 percent of the feed units consumed by all rumi­ nants in the United States are supplied by forages. Concentrates are fed in large amounts to dairy cattle and beef cattle in feed lots, yet forages domin­ ate. The amounts of grain fed vary with prices of grain and prices of the product produced. When economic conditions become less favorable, the amount of grain fed declines, particularly for beef cattle. As non-feed demands for grain increase in the future, the amounts available at favorable prices for ruminants probably will decline. Among these other uses are export, liquid fuel production, and sugar production.

Inasmuch as forages provide about 80 percent of the feed units consumed by beef and dairy cattle, and since these animals contribute 23 percent of the energy and 45 percent of the protein in our diets, we can calculate that 18 percent of the energy and 36 percent of the protein in the American diet has its origin in forages. No other commodity approaches forages as a contributor to the human diet in this country.

Forage and ruminant resources: There are three major forage regions in this country. They can be roughly demarked by two imaginary lines, one being the 97th meridian from the Canadian border to about Dallas, Texas,and thence south­ westerly to San Antonio, and the other being the 35th parallel eastward from the 97th meridian. West of the 97th meridian lies the arid and semi-arid lands. North of the 35th parallel is the humid-cool temperate region while south of it lies the humid, subtropical region. Each of the three regions is quite variable, yet each has unique characteristics. Table 1 shows the distri­ bution of various kinds of forage producing lands in these three regions.

Forage productivity in the two humid regions is much below potential. Pasture­ land and cropland hay and pasture production could be increased severalfold. (Hodgson, 1978; Bula et al., 1977). In the arid and semi-arid regions, poten­ tials for further productivity increases are lower and less likely to be exploited. Most rangelands are fully stocked now and costs of improvement are escalating more rapidly than values of products produced. Also, availability of water for expansion of irrigated forage land appears questionable. A more detailed discussion of potentials of these forage regions is given by Hodgson (1978), Bula, et a1. (1977), and Box (1977).

Nearly two-thirds of the beef cows and 86 perce.nt of the dairy cows are in the humid regions. This attests to the present forage production levels of the three regions. It further indicates that the livestock demands for more and better forage will be concentrated in the humid regions.

15 TABLE l--Approximate area of privately owned land devoted to various ypes of forage production by three major forage regions of the United States (millions of ha) Cropland Pasture- Range- Grazed Hay and Total Per- Total Forage Region land land Forest Pasture Forage cent Land

Humid, cool-temperate 24 4 15 21 64 23 245 Humid, subtropical 9 2 13 3 27 9 105 Arid and semiarid 9 l49a 27 9 194 68 301 TOTAL 42 155 55 33 285 100 651 aThere is an additional 106 million ha of federally owned rangeland available for grazing mostly in the arid and semiarid region.

SOURCE: B. D. Blakely and R. E. Williams. In: Grasslands of the United States. Iowa State Univ. Press, Ames, 1974.

Some considerations for the future: There is little doubt that world food needs will increase. The increase may be as much as 50 percent by 2000 A. D. This will result from an expected increase in population from 4.5 billion now to between 6 and 7 billion and from a rapid increase in affluence in many developing countries which translates almost immediately into greater food demands. We are likely to need all the food grains and livestock products the world can produce 25 years hence. There will be mounting demands on grains for export.

As world fossil energy supplies become more expensive and limited, and as energy demands increase, alternative sources of energy will become much more important. Considerable attention is being given to renewable sources includ­ ing agricultural crops traditionally used as food, feed, or soil cover. Feed grains, food grains, sugar cane and sugar beets, crop residues and other cell­ ulosic energy crops all have sizable potential markets as feedstocks for liquid fuel production. Such new uses will result in increased prices and probably reduced availability as feeds for ruminant livestock. This trend is a world­ wide one with many nations tooling up to convert grains to ethanol in prefer­ ence to exporting cheap food and importing expensive petroleum. When reason­ ably high proportions of such crops are diverted to energy use, it is likely that prices for those crops will be determined by petroleum prices.

New industrial and food uses for grains are emerging. The most striking is the capture of a sizable portion of the U.S. sugar market by fructose sugars made from corn. Such increased demands on agricultural production, particularly for grains, are likely to result in the need to replace, to a very considerable degree, the use of concentrates in livestock production. The most likely candidate for replacing concentrate feeds is forage. But, we must have high quality forage in much greater abundance to accomplish this. We cannot replace grain with low quality forage. In a recent paper in Science (Pimentel, et al.,

16 1980), the authors stated that, when grains become less available as feed for livestock, the production and consumption of foods of animal origin will decrease markedly. I do not believe this has to happen, but I believe it will happen if we do not exploit the potentials of forage quality more fully.

Forage Quality: A high quality forage is one that contains a high level of digestible energy and is consumed in large amounts per unit of time. Forage dry matter digestibility (DI1D) has a great impact on dry matter consumption, digestible energy consumption, and animal performance (Table 2). Note that, at 50 percent DMD, the level of digestible energy intake is only slightly above maintenance requirements. At 65 percent DMD, digestible energy con­ sumption is nearly 2.4 times maintenance, or adequate to produce 19.2 kg of milk per day. This approximates the present average production level of dairy cows in the United States. We now feed more than two tons of grain per cow per year to achieve that level of production. At 70 percent DMD, produc­ tion would be 29.2 kg per day or about 8100 kg per year (about 18,000 lbs). The data in Table 2 clearly show the potential for increasing milk production per animal. Liveweight gains by beef cattle show similar responses to forage quality. These data indicate that it will be of little advantage to a farmer to have a greater supply of low quality forage unless his goal is maintenance of animals only. The table also indicates the very large production responses to improved forage quality.

TABLE 2--Effect of forage dry matter digestibility on dry matter consumpt}on, digestible energy consumption and milk production of a 650 kg dairy cow 1

DM INTAKE DE Milk DMD % Consumed Produced % Body Wt kg/day Mcal/day kg/day 50 1.54 10.0 22.0 1.4 55 1.86 12.1 29.3 6.5 60 2.13 13.8 36.5 11.5 65 2.56 16.6 47.6 19.2 70 3.10 20.2 62.0 29.2

1/ Calculated from 1978 NRC Nutritional Requirements for Dairy Cattle ASSUME: a) Maintenance 650 kg cow = 19.95 Mcal DE/day b) 1 kg 4% fat milk = 1.44 Mcal DE c) No body weight changes during lactation

Forage quality is affected by plant species and cultivar, maturity at time of harvest, and the extent of losses during harvest and storage. Alfalfa is perhaps the leading forage from the standpoint of forage quality. It is of interest to examine what animal productivity from this crop could be and the impact of various factors on our failure to reach potentials.

The affects of maturity on forage quality, digestible energy consumption, and potential milk production are shown in Table 3. These data are for a very modest 8.3 tons per ha yield of alfalfa at bud stage. The data for DMD are real; the data for energy consumption and milk production are calculated.

17 DMD decreases by 8.5 percent from bud stage to full bloom. Digestible energy consumption of forage at these growth stages differs by 28.5 percent and milk production decreases by 45.4 percent. Potential milk production per ha decreases by about 3340 kg. At today's milk prices this represents a poten­ tial loss of more than $850 per ha.

TABLE 3--Alfalfa quality, DE consumption, and potential milk production 1/

Growth DMD DE/AC DE/Day Milk Produced Stage % Mcal Consumed kg/day kg/ha Mcal Bud 68.0 10,000 56 25.0 11,053 First Bloom 66.6 9,794 51 21.4 10,131 Half Bloom 64.4 9,470 46 18.2 9,251 Full Bloom 62.2 9,147 40 13.6 7,714 1/ Energy consumption and milk production per day for a 650 kg Holstein cow

Losses during harvest and storage can have disastrous economic consequences for the farmer. Table 4 illustrates the impacts of three hypothetical, yet not unrealistic, loss levels on DMD, digestible energy consumption, and milk production. Loss level (a) is routinely experienced with our best hay making procedures and favorable weather during harvest. Loss level (b) could be expected if the cut forage is rained on once and loss level (c) occurs after more than one wetting by rain. These data are for alfalfa cut at first bloom. Delayed harvest plus harvest losses compound the economic loss.

TABLE 4--Effects of post harvest losses on alfalfa quality and animal production

Loss Levels: (a) 10% of Dl-l and reduce DDM to 60% (b) 15% of Dl-I and reduce DDM to 57% (c) 25% of DM and reduce DDM to 50%

Loss DMD DE/AC DE/Day Milk Producedl/ Level % l-lcal Consumed kg/Day kg/ha Mcal

1430 Eound dair~ cow

a 60 7992 36.5 11.5 6219 b 57 7171 31.2 7.8 4441 c 50 5550 22.0 1.4 877

1/ Alfalfa crop as harvested at first bloom yielded 8.3 tons per ha. I/ Calculated for a 650 kg Holstein cow.

18

-~ These data indicate that, even with good weather during harvest and very good hay-making procedures (loss level a), we are realizing only about 56 percent of the potential milk production if we could get all the digestible energy in the standing crop into the cow. With poor weather we may realize only 40 percent, or less, of potential. Our inability to exploit the potential milk production per acre in alfalfa is very costly. The value of the highest potential milk yield in Table 3 is about $2875 per ha; the value at full bloom is about $2000 per ha. The value of milk production with best current harvest technology, as illustrated by loss level (a) in Table 4, is about $1600 per ha; with loss level (c) the value declines to about $225 per ha. This shows very clearly why farmers feed large quantities of grain to dairy cattle. It also shows that there is great opportunity to exploit forages more fully. It is of interest to note that, in ration balancing, animal nutritionists usually value alfalfa hay at about 55 percent DMD, about equiva­ lent to loss level (b) of Table 4.

Energy cost is almost daily becoming a more compelling factor in decision making on farms. Forages require only about one third as much fossil energy input as corn grain per megacalorie of digestible energy produced (Reid, et al., 1975). Substantial delays in harvest or large harvest losses negate most of the energy advantages of forages. Conversely, if we can find a way to get into the cow more of the digestible energy produced, then the energy advantage of forages would be enhanced. If this can be accomplished, then forage-livestock systems can compete very strongly with grain-livestock systems from an economic standpoint. Much sloping land, which now produces corn, would more profitably grow forages with consequential real advantages with respect to soil erosion.

The potential of forages in food production is very high -- much beyond levels now realized. The potential milk production from a modest 8.3 ton per ha alfalfa crop is about 11,000 kg per ha (9800 lbs per acre). We realize less than half of that. Furthermore, 8.3 tons per ha is not a very high yield by today's standards. Many farmers today obtain yields of twice that level. Thus, if we were to obtain potential yields and achieve potential utilization efficiency, we could increase milk production per unit of land area by severalfold. While the data presented here are for milk production, liveweight gains by beef cattle follow similar trends in relation to forage quality. We could produce ourselves the 100 million lbs of forage-fed beef that is now imported each month.

Given the probable future world demands for food and the expanding pressures for export and industrial uses of grain, it is especially important that we make substantial progress toward achieving the food production potentials of forages. Special emphasis must be given to reducing the excessive losses between harvest and feeding .. These losses are perhaps the most extreme losses in agriculture. Very large quantities of photosynthetically fixed energy are either lost or.rendered less available to animals by current har­ vest.and storage systems. Progress in increasing yield, pest resistance, or DMD 1n the standing crop by genetic means will have little payoff unless we are able to improve harvest and storage technology and reduce digestible ener~y l~sses. With. that improvement, increased forage yield and higher qua11ty 1n the s:and1ng crop will have a very large payoff. Achieving these goals would perm1t the movement of most of the grain now fed to ruminants to

19 other uses with little, if any, reduction in total production of food from ruminants. We have a responsibility to the American public to make this potential a reality.

References

Box, T. W. 1977. Potential of arid and semi-arid rangelands. In: Potential of the World's Forages for Ruminant Animal Production. Winrock Report. Winrock International Livestock Research and Training Center, Morrilton, Ark.

Bula, R. J., V. L. Lechtenberg, and D. A. Holt. 1977. Potential of temperate zone cultivated forages. In: Potential of the World's Forages for Ruminant Animal Production. Winrock Report. Winrock International Livestock Research and Training Center. Morrilton, Ark.

Hodgson, H. J. 1976a. Forages, ruminant livestock, and food. BioScience. 26:625-630.

Hodgson, H. J. 1976b. Forage Crops. Sci. Am. 234:61-75.

Hodgson, H. J. 1978. Food from plant products--forage. Proceedings of a Symposium on Complementary Roles of Plant and Animal Products in the U. S. Food System. National Academy of Sciences. Washington, D. C. November 29-30. Pimentel, D., P. A. Oltenacu, M. C. Mesheim, John Krummel, M. S. Allen, and Sterling Chick. 1980. The potential for grass-fed livestock: resource constraints. Science. 207:843-848.

Reid, J. T., K. L. Turk, and R. Anrique. 1975. Comparative efficiency of animals in conversion of feedstuffs to human foods. Unpublished paper. Rockefeller Foundation Symposium on the Future Role of Animals in Food Production. Wedin, W. F., H. J. Hodgson, and N. L. Jacobson. 1975. Utilizing plant and animal resources in producing human food. J. An. Sci. 41:667-686.

20 Development of Farm-scale Equipment for Alfalfa Fractionation

R. G. Koegel Departments of Agricultural and Mechanical Engineering University of Wisconsin Madison, Wisconsin

On-farm fractionation of freshly cut alfalfa into a pressed fibrous fraction for ruminant feeding and a juice protein concentrate fraction offers two major advantages:

1) It results in a harvesting system which is relatively weather independent, thus substantially reducing field losses.

2) It yields a high protein, low fiber fraction potentially usable for both ruminants or non-ruminants.

The quantity of this fraction is roughly equivalent to the protein normally lost or wasted by conventional harvesting and feeding practices.

Since, in many cases, most of the harvested forage will be used on the farm where it is produced, on-farm fractionation can eliminate substantial transportation costs involved in central processing.

Adoption of this process by farmers, however, has been hampered by the lack of machinery, which is suitable in terms of (1) through out, (2) acquisition cost, and (3) energy requirement. The University of Wisconsin-Madison has been working on processes and equipment for on-farm forage fractionation'which it is hoped will contribute filling these existing needs.

The fractionation process may be divided in four subprocesses:

1) Maceration (cell rupture) of the freshly cut plant material 2) Juice separation 3) Protein separation from the juice 4) Protein concentrate preservation/utilization

Maceration is accomplished by extrusion of the forage through orifices in die ring at an energy input of approximately two horsepower-hours per ton. While juice expression can be carried out by a variety of presses, a cone press or "vee" press has been developed at the UW which appears to have the potential for reducing the moisture of the pressed forage to the desired level with a modest energy requirement. Protein coagulation in the juice has most frequently been accomplished by steam injection. Separation has then been accomplished by floatation and/or a filter belt. Alternatelyaprotein fraction has been precip­ itated from the juice by addition of acid or by auto-fermentation. Pre­ s~~atio~ has been achieved by drying, pickling with acid, or by m~x~ng w~th dry grcund grain and ensiling. Utilization of Pressed Alfalfa and Plant Juice Protein

N. A. Jorgensen Dairy Science Department University of Wisconsin, Madison

Wet fractionation of green plants is a process that yields two major products, a high protein raw juice and a high fiber pressed forage (1,2). Advantages of wet fractionation are: independent from weather at harvest, better control of stage of maturity of plants at harvest, higher recovery of nutrients from the field, and more intensive utilization of plant nutrients as a food or feed.

The pressed forage contains over 70 percent of the original plant tissue dry matter and over 65 percent of the crude protein. The pressed forage is higher in cell wall constituents, up to 30 percent higher than the original plant tissue. Degree of change in chemical composition is influenced by the degree of pressure during the pressing operation. Pressed alfalfa forage represents the largest fraction and can be handled as a silage, dry hay, dehy­ drated meal, or fed fresh. Ensiled pressed forage undergoes a rapid fermenta­ tion (1). The resulting pressed silage has a greater loss of hemicellulose, a greater conversion of protein nitrogen to nonprotein nitrogen, a higher con­ centration of volatile fatty acids and a lower concentration of lactic acid than found in low moisture silage made from the original plant tissue. Dry matter intake and milk production were lower for cows fed the pressed silage (1). Addition of .5% formic acid improved preservation quality and resulted in dry matter intake and milk production equal to conventional low moisture silage (2). Apparent digestibility of dry matter was equal for the treatments (2).

Protein in the raw juice has been separated by heat coagulation and by fermentation. The heat coagulated and dried alfalfa protein concentrate (APC) contains over 40 percent .crude protein and less than 2 percent crude fiber. If made from low saponin alfalfa varieties, it is equal in feed value to control diets for chicks and growing swine over 45 kg body weight. The protein in APC made from regular and low saponin varieties were over 75 percent digestible in ruminant rations, with over 40 percent escaping rumen breakdown. This suggests APC prepared by heat coagulation may have advantages in ruminant rations. Heat coagulated APC (wet) mixed with dry ground shelled corn and ensiled was well preserved and accepted by growing swine and sheep. Current studies are under­ way to evaluate preservation techniques and utilization of wet APC. lRusse1l, J. R., J. P. Hurst, N. A. Jorgensen, and G. P. Barrington. Wet plant fractionation: utilization of pressed alfalfa silage. J. Anim. Sci. 46:278. 2Lu, C. D., N. A. Jorgensen, and G. P. Barrington. Wet fractionation process: preservation and utilization of pressed alfalfa forage. J. Dairy Sci. 62:1399.

22 Utilization of Oeproteinized Alfalfa Juice Michael Collins Department of Agronomy University of Wisconsin Madison, Wisconsin Juice removed from alfalfa during the mechanical dewatering process contains considerable concentrations of protein and minerals. The protein may be coagulated and removed by one of several methods and retained for animal feeding. The remaining juice may be utilized as a nutrient source for alfalfa and other crops, however, heavy applications of deproteinized alfalfa juice result in reduced yields and stand density. The deproteinization method used to coagulate the protein influences the composition and toxicity of the resulting juice. Research by Walgenbach et a1. (1977) indicated that the mineral content of ashed juice was not toxic when applied at levels that reduced yield where unashed was added. These results suggest that an organic compound may be involved in the toxicity of alfalfa juice to plants. A study was conducted to compare alfalfa response to juice deproteinized by several methods and to attempt to discover the basis for the observed toxicity. Juice deproteinized by heat, fermentation, sulfuric acid, and phosphoric acid was applied at rates of 0.0.5,1.0,1.5, and 2.0 cm surface depth to alfalfa in the greenhouse. In addition, a sample of sulfuric acid deproteinized juice was treated with polyviny1polypyrrolidone to remove phenolic compounds and applied at the same rates. Sulfuric acid deproteinized juice contained 0.31% N, 0.076% P, 0.488% K, and 0.241% S before phenolic removal and contained 0.32% N, 0.083% P, 0.517% K, and 0.236% S following treatment. Treating with polyviny1po1ypyrro1idone increased OM yield by 107% compared with untreated juice applied at the same" level (2 cm) (Table 1). The number of live plants remaining after two growth cycles averaged 19.2 for sulfuric acid minus phenolics compared with 25.0 for heat deproteinized juice and 0.4 for phosphoric acid treated juice at the highest application rate (2 cm). Tabl)e 1.--0ry matter yield of alfalfa fertilized with alfalfa juice deoroteinized bv several methods Oeproteinization Juice depth {cm Method 0 0.5 1.0 1.5 2.0 ------g/pot------fermented 1.32 1.97 0.70 0.09 0 sulfuric acid 1 .90 1 .83 1 .57 .73 phosphoric acid 2.02 .85 .16 .05 heat 2.05 sulfuric acid 1 .51 (phenolics removed) L • S• D. { O~O51 = 0 • 46 g, first flower maturity, greenhouse References Wa1genbach, R.P., Dale Smith, and H.W. Ream. 1977. Growth and chemical composition of alfalfa fertilized in greenhouse trials with deproteinized alfalfa juice. Agron. J. 69:690-694.

23 Alfalfa Seed Production Potentials for the 1980's Robert R. Kalton and Don E. Brown Land 0' Lakes, Inc. Speculation on alfalfa seed production potentials for the 1980's offers quite a challenge. There is no magic formula that can predict what will hap­ pen with any degree of accuracy. However, supportive information on the sub­ ject was obtained by summarizing USDA statistics on alfalfa seed production and yields per acre for major producing states and the USA over the last 40 years. These statistics were prepared as a handout. A second approach to the topic was development of a survey question~ naire covering some of the key aspects of alfalfa seed production. This questionnaire was sent out to over 40 alfalfa "seed experts" in the USA and Western Canada who are involved in production, conditioning, marketing, certi­ fication and research. Response to the survey was very gratifying with over an 80% return and a wealth of ideas on acreage yields and trends in the vari­ ous areas for the last 5 to 10 years and predictions for the near future. Other questions in the survey bearing on alfalfa seed production poten­ tials for the 1980's covered important advantages for production in the vari­ ous areas, major problems facing alfalfa seed production and producers in the future, and the types of problems, if any, of getting new varieties into seed production in different areas. The final and very opportune question in the survey pertained to needed research to help improve alfalfa seed production potentials in the future. A comprehensive summary of the responses to the survey questionnaire was prepared and is available from the authors. Discussion of responses was par­ titioned into the various regions of alfalfa seed production in the USA and Western Canada as production and yield trends, production advantages, problems facing growers in the future, and research needs varied from area to area. Special emphasis was placed on the many suggestions for research projects and these will be presented in detail at the conference. So, where does this leave us on alfalfa seed production patentials as we move into the 1980's. No one knows at this time what the demand (or usage) for alfalfa seed will be down the road. However, if we put all the information together, it appears that we have ample conditioning capacity, suitable acreage, experienced growers, and qualified plant managers and fieldmen in many areas of the West. Production, though declining in recent years, generally has been sufficient most years to satisfy demand for seed. Recently, however, growing problems with production and acreage yields have threatened the economic sta­ bility of the alfalfa seed industry for both growers and seed companies in several areas and are causing mounting worries in other areas. Some of these problems, like the weather and volcanic ash are uncontrollable and perhaps only temporary, while others like pollination, insect and disease control, and out­ of-date technologies mayor may not be amenable to solution in the long run. Based on the results of our survey a reassessment ef research inputs and needs on alfalfa seed production may be in order. Many good sound research suggestions from knowledgeable people were received. I believe all of us with a stake in the alfalfa seed industry should bring these needs to the attention of our public research agencies and our state and U.S. legislators in a call for action. Alfalfa is the prime forage crop and a great nitrogen fixer in many areas of the U.S.A. and Canada, and it behooves us to keep it on t~p via top quality profitable seed production, proper conditioning, efficient forage and conservation use,and a breeding and research environment necessary to sus- tain them all! 24 ALFALFA SEED PRODUCTION (Clean Seed) (1,ooots 1bs.)

Plains States Intermountain and PNW states Southwest states Period USA or Year S.D. Nebr. Kans. Okla. Texas Mont. Idaho Wyo. Colo. Utah Nevada Wash. Oregon Ariz. Calif. Total

1941-50 2,998 7,810 11,390 9,500 2,048 6,200 2,140 1,448 1,964 4,670 1,271 527 6,920 7,520 76,884 1951-60 8,217 8,462 11,885 7,738 2.656 6,340 6,932 2,249 2,818 10,542 352 11,852 3,034 6,044 59,342 155,253 1961-65 5,162 4,522 8,601 7,367 1,093 4,323 14,485 527 2,168 7,236 1,930 12,381 9,525 3,808 46,040 133,090 1966-70 4,990 2,106 5,475 7,175 1,071 3,293 13,916 348 798 4,046 6,422 14,205 6,625 1,628 43,096 117,548

1971 6,650 2,210 5,700 4,440 600 2,375 15,960 192 288 4,060 10,140 17,490 6,250 399 40,495 118,747 N U1 1972 5,070 1,300 2,880 6,090 960 18,540 2,970 9,250 19,610 6,840 240 31,490 105,465 1973 8,050 1,200 2,700 4,900 3,150 18,240 2,300 8,508 20,520 6,420 690 25,480 102,408 1974 7,020 2,175 3,600 5,365 2,700 18,200 5,100 8,400 17,280 7,350 900 32,670 111,300 1975 4,800 1,920 4,090 1,380 1,020 15,980 3,640 8,170 14,400 6,000 360 29,325 91,405

1976 5,265 1,840 5,280 3,800 2,400 9,620 2,365 4,083 12,150 4,565 400 28,080 80,748 1917 6,825 2,100 3,990 4,480 3,510 14,190 3,640 8,060 12,710 6,110 ISO 31,020 97,105 1978 12,750 2,400 6,900 7,975 2,210 15,050 4,350 6,205 10,260 4,830 17.920 91.615 , 1979 7,150 1,755 3,800 5,625 5,880 16,170 4,760 7,290 8,225 4.200 34,800 99,925

Compiled from USDA, Crop Reporting Board Statistics. ALFALFA SEED YIELDS (lbs./acre)

Plains States Intermountain and PNW States Southwest States Period USA or Year S.D. Nebr. Kans. Okla. Texas Mont. Idaho Wyo. Colo. Utah Nevada Wash. Oregon Ariz. Calif. Average

1941-50 58 74 71 98 129 78 88 75 91 108 201 98 164 182 86 1951-60 52 80 99 119 141 91 209 108 136 197 305 488 360 211 418 162 1961-65 55 75 94 127 136 90 313 70 138 167 271 449 500 191 405 193 1966-70 62 68 91 133 132 90 384 75 114 154 377 541 504 116 426 211

1971 70 65 95 120 120 95 420 80 115 290 520 530 500 95 445 239

N 1972 65 65 80 145 80 515 330 500 530 510 150 410 282 CD 1973 10 60 90 140 105 480 230 415 540 535 230 455 248 1914 65 75 90 145 90 455 300 500 480 525 200 495 244 1975 60 80 95 115 85 410 280 430 450 500 180 515 261

1976 65 80 110 200 100 310 215 355 450 415 160 585 231 1977 65 15 95 140 90 430 260 520 410 410 150 660 238 1978 85 75 115 145 85 350 290 365 285 345 280 173 1919 55 65 95 125 140 385 280 405 235 300 435 201

Compiled from USDA, 'Crop Reporting Board Statistics. Leafcutting Bees for Fun and Profit W. P. Stephen Oregon State University Corvallis, Oreg.

Since the potential of the leafcutting bee, Megachile rotundata, as an alfalfa pollinator was first recognized in 1959 (1), enormous local popula­ tions have been developed in many areas of western America. The ease with which bee populations could be established during the 1960's, the efficiency of the bee as an alfalfa pollinator, plus its amenability to management and control caused many producers to hail the species as the panacea to alfalfa pollination. - By 1970 the leafcutting bee was propagated for alfalfa pollination in most of the states west of the Great Plains and in all of the western provinces of Canada. Populations of various sizes have been sent to over 20 foreign countries on all continents, but only in a few of these have they been successfully established in economic numbers. Between the time of its introduction into the US - some time prior to . the mid 1930's - and the early 1960's, the species had spread widely across the central latitudes of America north of Mexico. In areas such as t~e Pacific Northwest, where an established seed production industry provided a superabundance of forage, the leafcutting bee flourished. Trapping, that is simply providing nesting tunnels in the form of drilled boards, paper soda straws, corrugated cardboard, etc., (2) was successfully undertaken by farmers, enterprising townsfolk, Boy Scout troups,and 4-H Clubs. The success in luring endemic populations of the bee to such materials confirmed our suspicions that the population size of the bee was limited by appropriate material in which to nest. A lay-trade in bee-filled boards and straws flourished from shortly after the value of the bee was recognized until the early 1970's. During this period, the densely aggregated populations fell prey to a variety of general parasites and predators, few of which were recognized or controlled by the general bee trapper. As a result, the propagation of the bee passed largely into the hands of specialists located in more remote non-seed areas of the west. The bee itself became the cash crop in many marginal seed areas of Western Canada and the United States and alfalfa seed the ancillary industry. The development of the leafcutting bee industry reached maturity in the mid 1920's with the sudden appearance and rapid spread of chalkbrood in western America (3). Bees are currently sold on the live larvae/pound basis with the quality of the bees usually determined by X-ray analysis (4). It is estimated that 750 million cells have cleared market channels in each of the past five years. Their value has stabilized at from 1.5 to 2.5 cents/larva. After 20 years the leafcutting bee remains the key factor in the alfalfa seed production in much of western America. The fun once associated with the ease of trapping and marketing remains, but greatly modified in form: profit is clearly present to the bee propagator, and ultimately to the seed producer. References 1. Stephen, W.P. & P.F. Torchil. 1961. Pan. Pac. Entomol. 37: 85-93. 2. Stephen, W.P. & R.W. Every. 1970. Ore. State Univ. Fact Sheet 175. 3. Stephen, w.P. & J.M. Undurraga. 1978. Ore. State Univ. Sta. Bull. 630. 4. Stephen, W.P. & J.M. Undurraga. 1976. J. Apic. Res. 15: 81-87.

27 Ineffective Alfalfa Nodules: How and Why c.P. Vance and L.E.B. Johnson USDA-SEA-AR and The Department of Agronomy and Plant Genetics University of Minnesota St. Paul, Mirm.

Root nodule tissues from an effective association and three ineffective associ­ ations between alfalfa and Rhizobium meliloti were compared histologically. In nodule tissue formed by ineffective ~ meliloti strain 102 F26, rhizobia released into host cells sometimes became enveloped in large masses of an apparent polysaccharide-like material and did not develop into bacteroids. Bacteroids produced by this strain were smaller and showed fewer pleomorphic shapes than bacteroids in effective nodules. Nodules induced by this strain senesced much more rapidly than effective nodules. MnSa(In) is an alfalfa genotype that produces ineffective nodules with normally effective strains of R. meliloti. These nodules were similar in shape size and color to nodules produced by R. meliloti strain 102 F26. Bacteroids, produced on MnSa(In) plants, aggregated and senesced shortly after filling the nodule cell. Starch formation was more apparent in MnSa(In) than in effective nodules. MnPL-480, another alfalfa genotype, produces ineffective nodules with most effective strains of R. melioti and was strikingly different than either effective or ineffective nodules induced by wild type R. meliloti strains. MnPL-480 nodules were tumour-like and most cells were filled with starch. In contrast to effective, bacterial induced ineffective and MnSa(In). MnPL-480 nodules had few infected cells and little proliferation of infection threads. The three types of ineffectiveness, described here, appear to be expressed differently. Ineffective associations may be expressed at more than one level within the nodule. Expression of ineffectiveness may be analogous to expression of disease resistance.

28 Inheritance of Five Traits Conditioning Ineffective Nitrogen Fixation in Alfalfa M. E. Peterson and D. K. Barnes University of Minnesota and USDA, SEA-AR St. Paul, Minn.

Alfalfa has the potential to fix more nitrogen (N~) than other legumes on a seasonal basis. Alfalfa plants that are unable to fix N2 have no advantage over forage grasses when used in cropping systems, but non-nodulating (non-nod) and ineffectively nodu­ lated plants can be useful in studying the processes of root infection, nodule for­ mation, and N2 fixation. Viands et a1. (1) isolated an ineffectively nodulated alfalfa plant at Minnesota. Since then four additional alfalfa plants with ineffective nodules and a non-nodu- lating genotype were isolated. The objectives of this study were to determine if the five ineffective nodule clones were controlled by the same genetic system and to de­ termine the inheritance of the different ineffective nodule traits and the non-nod trait. The non-nod clone and the five ineffective clones were self pollinated, crossed in a dia11e1 mating design, and crossed to two effective normal nodulating clones. F2 and backcross seed were produced on non-nod x normal and ineffective x normal crosses. F2 seed was also produced on non-nod x ineffective crosses and ineffective x ineffec­ tive crosses. All progenies were evaluated under nil-nitrate greenhouse sand culture. Six weeks after planting non-nod plants were small, chlorotic, and had no nodules. Plants with ineffective nodules were small, chlorotic, and had white nodules. Plants with effective nodules were vigorous, dark green, and had pink nodules. Results from the ineffective x ineffective crosses indicated that four different host-determined ineffective nodule traits existed. All four traits were simply in­ herited, recessive to effective N fixation, and were expressed in the presence of normally effective rhizobia1 strains. Three of the ineffective nodule traits were each conditioned by a single tetrasomica11y inherited recessive gene (in , in2, in ). The nu1lip1ex condition for each trait produced ineffective nodules. The1 fourth in­3 effective nodule trait was controlled by two recessive genes (in4 and ins) with tetra­ somic inheritance. The nu11iplex condition at both loci was required for the produc­ tion of ineffective nodules. F2 segr.egation from the six ineffective x ineffective crosses substantiated the relationships among the four ineffective traits. The non-nod trait was simply inherited and recessive to normal nodule formation. The nu11ip1e~ condition of two tetrasomica11y inherited recessive genes (~ and nn2) was requlred for non-nodulation. F2 segregations of non-nod x ineffective crosses indicated that the non-nod clone was homozygous for the ineffective nodule gene in3 and homozygous for the ineffective nodule gene inJ. F2 segregations from three non­ nod x ineffective crosses indicated that the non-nod trait and the four ineffective nodule traits segregated independently of one another. The non-nod trait and the four ineffective nodule traits should be useful in identi­ fying specific factors important to the root infection, nodule formation, and N fixation processes. Gene pools homozygous for the non-nod trait and each ineffective trait are being developed and increased for use in N fixation research, and will be released in 1981. References 1. Viands, D. R., C. P. Vance, G. H. Heichel, and D. K. Barnes. 1979. An ineffec­ tive nitrogen fixation trait in alfalfa. Crop Sci. 19:905-908.

29 Com etitive Abi1it of Alfalfa

Gudni Hardarson Department of Agronomy and Plant Genetics University of Minnesota St. Paul, Minn. Inoculation by effective strains of Rhizobium me1i10ti has not been found to increase yields of alfalfa significantly in Minnesota soils. Even in soils without a cropping history of alfalfa, inoculation was of no benefit. Barnes et a1. (1979) speculated that this was because R. meliloti had been introduced b~ wi~d ~nd dust from areas where alfalfa was grown. The present investiga­ tlon lndlcated that most of the indigenous R. me1i10ti in Minnesota soils are either effective or moderately effective in-nitrogen fixation. The introduc­ tion of new strains of Rhizobium into Minnesota soils and to other similar soils in the upper midwest will probably not result in increased yield and nitrogen fixation unless the introduced rhizobia are superior to the in­ digenous strains in effectiveness of nitrogen fixation and in competitive ability in nodulation. The competitive ability for nodulation of effective and ineffective strains of R. me1iloti was investigated in two cu1tivars of alfalfa. Antibiotic re­ sistant mutant strains of Rhizobium were used to verify that the seedling growth responses in zero nitrogen caused by a binary mixture of Rhizobium were attributable to the relative proportions of effective and ineffective nodules on each plant. A significant positive correlation was observed between the percentage of nodules produced by the effective strains and both the dry matter production of the plants and the rate of acetylene reduction. The re­ sults show that competitiveness of binary mixtures of R. meli10ti on alfalfa seedlings can be measured using either dry matter yield or acetylene reduc­ tion assay. Only infrequent confirmation with antibiotic mutants that seed­ ling yields or nitrogenase activity is correlated with the proportion of nodules produced by the tested strain would be necessary. The results also show that preference by alfalfa plants for effective and ineffective strains at zero nitrogen can be measured using shoot dry weight. Plants selected by this method could be used to breed for uniform preference for effective strains of Rhizobium. Results on the inheritance of preference for strains of R· trifolii by white clover (Trifolium repens L.) (Hardarson and Jones, 1979). support this idea. The legume-Rhizobium symbiosis should approach the optlmum level of efficiency when both the plants and Rhizobium genotypes are selected for simultaneously. References 1 • Barnes, D. K., C. P. Vance, and G. H. Heichel. 1979. Seed coating and nodulation effectiveness in alfalfa. In Proceedings of the Ninth Annual Alfalfa Symposium, University of Illinois and the Certified Alfalfa Seed Council, March 13-14,1979, Peoria, IL. 2. Hardarson, G., and D. G. Jones. 1979. The inheritance of preference for strains of Rhizobium trifolii by white clover (Trifolium repens L.). Annals of Applied Biology 92:329-333.

30 Field Survey of Acetylene Reduction Rates in Legumes Growing on Western Rangelands D. A. Johnson and M. D. Rumbaugh USDA/SEA-AR Utah State University Logan, Utah Because legumes are known to add significant amounts of nitrogen to pastures in eastern and midwestern United States, suggestions have been made that legume species may also be beneficial on western U.S. rangelands. However, plants growing on many western rangelands may experience considerable drought and high temperature str'ess. Because of these stresses, it has been proposed that biological nitrogen fixation in these areas may be negligible, if present at all. Little documentation exists that quantifies the nitrogen fixation capabilities of legume associations growing on western rangelands. This study was designed to survey field acetylene reduction rates of native and introduced legumes in representative range environments of the Western United States. Estimates of nitrogen fixation were obtained throughout the 1979 growing season using field acetylene reduction procedures. Two 19.8 cm long and 7.6 cm diameter soil cores were taken over the center of the main stem of each plant and placed in cloth bags. These bags were placed in a polyvinyl chamber equipped with a fan for air circulation and exposed to a 10% acetylene atmosphere for 1 hour. After the l-hour exposure period, gas samples were withdrawn and placed in 10 m1 vacua ted blood collection vials. The vials were then taken to the laboratory for subsequent ethylene analysis by gas chromatography. Immediately after obtaining the cores, 10 repre­ sentative stems of each species were evaluated for plant water stress with a pressure bomb apparatus. Because of the relatively small number of samples that could be assayed with the s?il cor~ procedure and because of typically large standard deviations assoclated wlth acetylene reduction determinations, few differences were statistically significant. However, trends indicated that acetylene reduction rates wer~ positive fo~ both native and introduced legumes in a number of range en~lronments. Hlghest acetylene reduction rates were found early ;n ~he gro~lng season. Acetylene reduction activity generally declined with ~ncrea~l~g plant w~t~r s~ress. Medicago sativa was particularly notable in l~S ablllty to exhlblt hlgh acetylene reduction rates on a number of range sltes.

31 Nitrogen Fixation of Alfalfa After Harvest

H. T. C.r:-alle and G. H. Heichel University of Minnesota and USDA, SEA-AR St. Paul, Minn.

Nitrogen fixation by alfalfa requires a large expenditure of energy from photosynthates for nodule growth and function. The removal of photosynthetic tissue from alfalfa at harvest, and the requirements of vegetative regrowth and nodules for reserve carbohydrates and current photosynthate, may limit the capacity of alfalfa to sustain nitrogen fixation. We examined the effect of photosynthate supply on alfalfa nitrogen fixation with treatments of periodic harvesting, continuous leaf removal, and prolonged exposure to darkness.

Nitrogen fixation capacity as measured by the acetylene reduction assay fre­ quently declined after herbage removal. The magnitude of this decline de­ pended upon the severity of the harvest. In the first of two successive harvest cycles, 75% leaf area removal did not affect nodule activity. In the second harvest cycle, 85% leaf area removal reduced nitrogen fixation 49%. Total herbage removal reduced nodule activity 78% after the first harvest and 86% after the second harvest.

Recovery of nitrogen fixation capacity after the decline caused by harvest commenced as herbage regrew and paralleled leaf area expansion. Nodule activity usually recovered to pre-harvest values in 10 to 15 days, about one-third to one-half of the interval between harvests.

Nitrogen fixation of unharvested control plants that flowered and set seed during the course of the experiment changed little compared with that of harvested plants. For the unharvested controls, the major change in nodule activity occurred after release of axillary and terminal bud dormancy fol­ lowing flowering. Nodule activity of plants subjected to continuous removal of new leaves after complete defoliation, or to continuous darkness, declined significantly and never recovered during the experiments.

Decline and accumulation of root nonstructural carbohydrates varied with harvest treatment in the expected manner. However, the patterns of change in carbohydrates caused by harvest were much different in phase and amplitude from those of nitrogen fixation capacity. This suggests that root non­ structural carbohydrates are of greater importance to vegetative regrowth than to maintenance of nodule activity.

The observation that partial harvest was less deleterious than complete har­ vest to nitrogen fixation suggests that the basal leaves of alfalfa are im­ portant in supplying current photosynthate to the nodules. Nitrogen fixation of alfalfa might be improved by selecting plant material with impro~ed re­ tention and photosynthetic activity of lower leaves; or plant mater1al that efficiently partitions photosynthate from lower leaves to the nodules.

32 Nitrogen Fixation of Alfalfa Measured by lSN Isotope Dilution

G. H. Heichel, D. K. Barnes, and C. P. Vance USDA, SEA-AR and the University of Minnesota St. Paul, Minn.

Alfalfa obtains nitrogen from the soil and from the atmosphere by symbiotic nitrogen fixation. It is necessary to identify the contribution from each nitrogen source to evaluate nitrogen fixision of different alfalfa germplasms. Field experiments were undertaken using N as a tracer of nitrogen metabo­ lism to compare the seeding year performance of two populations selected for improved nitrogen fixation in the greenhouse with that of the standard cultivar 'Saranac'. Additional objectives were to investigate the effects of stage of plant development, and herbage versus whole plant sampling, on assessments of nitrogen fixation in the field.

During the seeding year, field communities of the two experimental popula­ tions averaged about 43% of their nitrogen needs from symbiosis, compared with 36% for Saranac. The experimental populations fixed an average of about 148 kg/ha of nitrogen during the growing season, compared with 109 kg/ha for Saranac. Nitrogen fixation was least (4 to 20 kg/ha) in the first and fourth harvest intervals, and greatest (38 to 87 kg/ha) during the second or third harvest intervals. The isotope-dilution and A-value methods gave similar assessments of performance over the four harvest intervals.

The proportion of nitrogen derived from symbiosis for whole plants of seeded and transplanted materials differed significantly (P

In contrast to gre~nhouse evaluations of nitrogenase activity, significant (P

33 Investigations on Distribution, Growth Rate, Resistance to, and Host Range of Race 1 and 2 of CoZZetotpiahum trifoZii

Ronald E. Welty, Ramzy Y. Gurgis, and Dennis E. Rowe USDA-SEA-AR, Forage Research Unit Oxford, N.C.

Anthracnose, induced by ColZetotpichum trifoZii, is widespread on alfalfa in the Mid-Atlantic United States and causes moderate to severe damage. In 1979 strains of the fungus capable of inducing disease in previously anthracnose- ' resistant Arc and Liberty alfalfa were reported from North Carolina (Plant Dis. Rep. 63:666-670) and Maryland (Plant Dis. Rep. 63:734-736). Subsequently, it was proposed the new strains be designated Race 2.

In July 1979, stems with anthracnose lesions were collected from 8 fields of alfalfa in 5 counties. Stems were surface sterilized and incubated in a moist chamber. Sporulating lesions were rubbed on stems of Saranac seedlings and plants were kept moist for 72 hr. Inoculated plants that collapsed were cultured and 63 isolates of 3 species of CoZZetotriahum were recovered.

Nineteen isolates with spores that most closely fit the average length and width of C. trifoZii conidia described by von Arx (J. Phytopathol. Z. 29:413- 468) were selected. Seedlings of Arc and Saranac AR were inoculated with spores from single-spore cultures of each of these 19 isolates and also with known cultures of Race 1 and 2. All 19 isolates were of Race 2 and 17 had been obtained from plants in 1 to 3-yr old stands of Arc alfalfa in Iredell, Rmvan, and Davidson (NC) Counties. The remaining cultures, including C. destructivum and C. dematum f. sp. truncata were stored for later testing.

Mycelial growth of 3 isolates of Race 2 (NC-4, D-3-9, M-8) was compared to a Race 1 isolate (PA) on corn-meal agar at 4 to 36 C, in 4 C increments. Optimum growth for all isolates occurred between 20-28 C and minimum and maximum temperature for growth was 8 and 32 C, respectively.

Resistance to Race 1 (PA) and 2 (NC-4) was evaluated in 31 alfalfa cultivars and breeding lines. Resistance to Race 2 was found in Saranac AR, Vangard, and in breeding lines with Saranac AN 4 or Vernal AN 4 in their pedigree.

Several forage legumes were inoculated in the greenhouse with both races of C. trifolii. Race 1 (PA) and 2 (NC-4) becam: sys~emi: in.Medicago sativa and Melilotus alba; Race 2 became systemic 1n T.r~fol~um ~ncarnatum. Both races defoliated Coronilla varia~ T. pratense~ T. repens~ T. subterraneum~ and Vicia villosa~ whereas Race 1 defoliated T. vesiculosum~ T: dubium~ and T. incarnatum. Both races induced lesions on leaflets and pet10les o~ Lespedeeza cuneata~ Race 2 induced lesions on T. vesiculosum~ T. hybr~qum~ . tum d T dub~um and Race 1 induced lesions on Lotus corn~cuZatus3 T. resup~na ~ an • '" · Z tu T. resupinatum and T. hybridum were nonhosts for Race 1 and L. ~orn~~ a s was a nonhost for Race 2. This extends the host range of C. tp~fol~~ to include more legume hosts than alfalfa, crimson clover, red clov:r, and sweet clover and suggests physiological specialization for legume spec1es rather than just alfalfa cultivars.

34 The Occurrence of Race 2 of Colletotrichum trifolii in the Mid-Atlantic States S. A. Ostazeski and J. H. Elgin, Jr. Science and Education Administration, U.S.D.A., Beltsville Agricultural Research Center, Beltsville, Md. During the summer of 1979, an alfalfa anthracnose survey was made of fields randomly selected within a day's drive of Beltsville, Md. Collections were made in southeastern Pennsylvania, Delaware, Maryland and Virginia. Depending upon the seriousness of the local infestation as few as 1, or as many as 10, infected stems constituted a collection from one location. In the laboratory, sections of lesion-bearing stems were incubated in petri dish moist chambers to promote sporulation. Fruiting isolates were identified to species, and if Colletotrichum trifolii, spore masses were streaked onto oat­ meal agar slants. All isolates were stored as tube cultures under refriger­ ation until further processed. Graham's petri dish technique (1) was used to initially characterize isolates as to race as follows. A spore suspension of the test isolate was spread over cornmeal agar in three petri dishes and incu­ bated at least 48 hours. Surface sterilized seed of 'Saranac', 'Saranac AR', and 'Arc' were uniformly spread, one cultivar/dish, over the fungal growth. Seeded plates were allowed to incubate 10 to 14 days before classification. Check plates of these same cultivars were seeded onto known race 1 and/or race 2 cultures. Isolates giving a positive race 2 reaction were further tested by challenging seedlings of the above cultivars growing in 4-inch pots, with conventional spray inoculations. Only race 1 was isolated from the five locations sampled in southeastern Pennsylvania and eight locations in Dela­ ware. Of five locations sampled in Virginia, race 2 was isolated from only one field near Culpepper. Of the seven locations sampled on Maryland's east­ ern shore, race 2 was isolated, as in 1978, only at the Cambridge location (2). Of 19 locations sampled on Maryland's western shore, race 2 was isolated from fields at Clarksville, Largo, and two sites on BARC-East at Beltsville. Welty and Mueller (3) reported earlier the occurrence of what is now known to ~e race 2 from North Carolina. Therefore, Virginia is now known to have at least one infestation of race 2, and in Maryland, race 2 has been found in . three locations in addition to the original Cambridge site.

References

1 • Graham, J. H., T. E. Devine, J. E. McMurtrey, and D. L. Fleck. 1975. Agar plate method for selecting alfalfa for resistance to Colletotrichum trifolii. Plant Dis. Reptr. 59:382-384. 2. Ostazeski, S. A., J. H. Elgin, Jr., and J. E. McMurtrey III. 1979. Occurrence of anthracnose on formerly anthracnose-resistant 'Arc' alfalfa. Plant Dis. Reptr. 63:734-736. 3. Welty, R. E. and J. P. Mueller. 1979. Occurrence of a highly virulent i~olate of Colletotrichum trifolii on alfalfa in North Carolina Plant D1S. Reptr. 63:666-670. •

35 Effect on Downy Mildew Reaction of Selecting for Saponin Content in Alfalfa D. L. Stuteville and E. L. Sorensen Departments of Plant Pathology and Agronomy, and USDA-SEA-AR Kansas State University Manhattan, Kans. Pedersen et ale (3) reported that downy mildew (OM) resistance was not changed significantly by selecting for high (H) and low (L) saponin (S) concentration in six alfalfa cultivars. However, Berkenkamp et ale (2) noted much less mildew on HS Ranger than on LS Ranger plants. To study this relationship further, we determined the resistance to Peronospora tPifoZiorum d By. (three monoconidial isolates) of HS, LS, and unselected seedlings from six cultivars. Seed of HS and LS selections was supplied by M. W. Pedersen. Four replica­ tions of about 30 seedlings each were tested under controlled conditions in the laboratory (I).

Selecting for S content affected DM resistance in all six cultivars. Howeve~ the correlation coefficient between S index (3) and OM resistance was low for each of our isolates. For Ranger and Vernal, and their selections, OM resistance was positively associated with S content (Table I). For the other four cultivars, OM resistance of both the H and L selections was less or not significantly different from that of the parent. However, except for Ladak and Lahontan, OM resistance to each Table l~-The mean percentage of isolate was greater for the HS than for alfalfa seedlings free of downy the LS selection. These data indicate mildew after inoculation with that the effects on OM resistance during specified monoconidial isolates selection for S content cannot be pre­ of Peronospora trifoZiorum dicted accurately. However, they suggest that LS alfalfa cultivars gener­ cultivar and Isolate ally will be susceptible to OM. saponin level I-5 I-7 I-8 OuPuits 36.4z 13.9 50.6 References .6 Low .8 0 1. Barnes, o. K. et ale 1974. Standard High 13.7 1.4 40.1 tests to characterize pest resistance Ladak 19.2 9.0 20.0 in alfalfa varieties. ARS-NC-19. Low 14.0 2.5 5.4 6.7 High 10.4 1.8 2. Berkenkamp, B., L. P. Folkins and Lahontan 13.1 6.5 7.8 J. Meeres. 1978. Resistance of Low 8.2 11.5 2.1 alfalfa cultivars to downy mildew. High 1.2 0 o Can. J. plant Sci. 58:893-894. Ranger 17.0 8.3 9.4 Low 15.0 1.9 4.8 3. Pedersen, M. W. et ale 1976. Effects of low and high saponin High 46.0 20.3 27.8 selection in alfalfa on agronomic Uinta 48.1 20.0 56.2 and pest resistance traits and the Low 23.0 3.9 7.2 interrelationship of these traits. High 36.4 10.0 21.5 Crop Sci. 16:193-199. Vernal 10.5 22.5 10.2 Low 7.8 7.0 4.3 High 25.6 45.6 30.6 zoifferences of 5.9 or less between any two values are not statistically significant (p=0.05). 36 Effect of Spring Black Stem on Alfalfa Forage Yield in the Greenhouse and Possible Selection t-1ethodology E.H. Hijano and F.I. Frosheiser Department of Plant Pathology and USDA-SEA-AR University of Minnesota St. Paul, Minn. Although the causal agent of spring black stem of alfalfa (Phoma medicaginis Malbr. & Roum. var. medicaginis) can infect and produce damage on most of the different tissues of the alfalfa plant, leaf spotting and stem blackening are the most common symptoms observed in the field. In only a few cases have these symptoms been related to yield losses. Amount of damage caused by the disease has been based on visual estimates of losses in the field or by comparing unsprayed versus fungicide-treated field plots (1,3). However, under natural conditions, other pathogens are usually present, reducing the accuracy of these estimates. The present study was made to determine the relative effect of leaf and stem phases of ~ medicaginis infection on yield and plant growth, by means of artificial inoculations in the greenhouse. Leaves and stems infected simul­ taneously produced 44% less dry matter than the non-inoculated control. Infecting leaves of stems separately produced 32 and 21% less dry matter than the control, respectively. Inoculating leaves and stems, leaves only, or stems only caused a reduction of alfalfa growth of 26, 9 and 17% respective­ ly, measured as stem elongation 15 days after inoculation. A seedling-box method (2) previously used for evaluating alfalfa for anthrac­ nose resistance was adapted to spring black stem. Inoculating seedlings when 50% of the unifoliolate leaves were expanded, appeared to be an appropri­ ate growth stage for ragid screening against this disease, using an inoculum concentration of 4 X 10 spores/ml plus 1% glucose and two drops of Tween 20/50 ml of inoculum. A 48 hr dark treatment following inoculation was necessary to slow down seedling growth and to allow the pathogen to infect and kill susceptible seedlings. Temperatures in the range of 18 to 24C were the most favorable for disease development. Since percentage of escapes were somewhat high, this method is .proposed as the first step in the screening procedure. Surviving plants later are transplanted to individual pots and inoculated to eliminate escapes.

References

1 • Bantta:i, E.E., L. Sundheim and R.D. Wilcoxson. 1963. Chemical control of spr~ng black stem of alfalfa. Plant Dis. Reptr. 47:682-685. 2. Morrison, R.H. 1977. A seedling-box test for evaluating alfalfa for resistance to anthracnose. Plant Dis. Reptr. 61:35-37. 3. Willis, W.G., D.L. Stutville and E.L. Sorensen. 1969. Effect of leaf ~~g.stem disease on yield and quality of alfalfa forage. Crop SCi. 9:637-

37 Surface Sterilization of Alfalfa Seed and Alfalfa Plant Tissues with Chlorine Gas

B.D. Thyr, B.J. Hartman, N.P. Maxon, and S.A. Fazal Farook, USDA and University of Nevada, Reno, Nev.

Growth of alfalfa callus from seed or other tissue requires contaminant-free culture to be useful in genetic or pathologic studies. Alfalfa callus can be used as a medium for cuI turing nematodes and possibly in screening for resis­ tance to microbial toxins (1). However, the seed first must be treated to eliminate surface-borne microbial contaminants. NaOCl and HgC12 have been commonly used but NaOCl is rather ineffective and HgC121 the most effective of the two, has lost favor due to health and safety considerations. Chlorine gas, generated by combining NaOCl and HCl, is as effective as HgC12 for surface disinfecting seed, but unlike HgC12' it leaves no residual toxic elements on the seed following treatment.

Gram equivalents of NaOCl and HC are combined for the reaction. 100ml of household bleach (5.25% NaOCl) is put into a flask or beaker and placed in a dissicator jar under a fume hood. The seed or other tissue is arranged around the container of bleach in small petri dishes with lids removed and set aside in the jar. The dissicator lid with a hole in top for a stopper is put into place with stop-cock grease to seal the ground surfaces. Concentrated HCl (3.3ml) is poured through the hole and into the bleach solution and the hole stoppered. The fume hood exhaust should run throughout the treatment period,which will vary depending on the type of tissue. Seed may be left in 24 hours with only slight reduction of germination. Mean percent germination of four cultivars exposed to NaOCl (0.525%), HgC12 (0.1%), Chlorine gas,and the control was 81, 81, 72, and 82 respectively. Percent seed contaminated following treatment with NaOCl (0.525%), HgC12 (0.1%), Chlorine gas (24 hr), and the control was 25.2, 1.9, 1.1, and 44.7, respec­ tively. A major advantage of the gas treatment over liquids is the ease with which dry seed can be handled following treatment, with little or no danger of damaging or contaminating seed in handling, as there is with wet. Disease of tissue can be treated to remove surface contaminants so pathogenic organisms can be isolated. Fresh leaf, stem and root tissue, depending on its bulk should be left exposed to the gas for 1-30 minutes. One must exper­ iment wi~h the time interval to arrive at the optimum period for a given set of circumstances. Credit should go to the USDA Cotton Research Laboratory at Phoenix, Arizona, where a similar procedure has been used for surface-sterilization of cotton seed.

References

Thyr E.J. Maxon, B.J. Hartman, and S.A. Fazal Farook. 1. Maxon, N•• P , B ••D , .' . 1980. Callus growth of Medicago sativa L. on med1um conta1n:ng isolated toxins of Colletotrichum trifolii. Proc. XXVII Nat10nal Alfalfa Improvement Conference. Madison, WI.

38 Consumption, Assimilation, and Conversion of 15 Forage Legumes by Lepidopteran larvae in Wisconsin

J. Mark Scriber Department of Entomology University of Wisconsin Madison, Wis.

Consumption and utilization of plant biomass, energy and nitrogen for insect growth is regulated by environmental (e.g. microclimate) conditions, foodplant quality (e.g. nutritional content versus allelochemics), and coevolutionary history of the insect and host plant(s). Behavioral, physiological, and genetic adaptations by insects may occur as fast as new cultivars are selected and bred for resistance. While spectacular success has been achieved with resistance in forage legumes to certain homopterous insects (e.g. aphids), little or no resistance has been identified against monophagous or polyphagous Lepidoptera (1).

In this regard, the relative roles of the above mentioned determinants of larval growth rates have been investigated using a polyphagous lepidopteran species, Spodoptera eridania, which has unusually high capabilities for detoxifying a variety of "secondary" plant products. Extreme differences in metabolic costs were observed for larvae on 15 different forage legumes; however, increased consumption rates where metabolic expenditures were high (i.e. where efficiencies were low) permitted rapid growth of armyworms in all no-choice experiments. Reasons for the extremely high metabolic expenditures on Team, Arc, and Culver alfalfa compared to Vernal alfalfa, Apollo alfalfa, and Yellow Blossom sweet clover are uncertain at this time but involve an interaction of allelochemics and nutrients (2,3).

Accurate predictions of herbivorous insect pest population dynamics will depend upon a thorough understanding of their nutritional ecology. While heat unit calculations are extremely helpful in this regard, the degree of precision obtained in estimating developmental time or assessing damage thresholds is restricted by variation in cu1tivar quality and insect adaptability in its consequent feeding, growth, and reproductive responses. References

1. Nielson, M.W. and W.F. Lehman. 1980. Breeding approaches in alfalfa. pp. 277-311 In (F.G. Maxwell and P.R. Jennings, eds.) Breeding Plants Resistant to-:Insects. John Wiley and Sons, N.Y. 683 pp. 2. Scriber, J.M. 1979. Post-ingestive utilization of plant biomass and nitrogen by Lepidoptera: Legume feeding by the southern armyworm. J. New York Entomo1. Soc. 87: 141-153. 3. Scriber, J.M. and F. Slansky, Jr. 1981. The Nutritional eoclogy of insects. Ann. Rev. Entomol. 26: in press.

39 The Effects of Seeding Rates on Stand Longevity, Stand Count, Stem Number ~nd Forage Yield of Alfalfa

B.J. Hartman, R.N. Peaden, B.D. Thyr and O.J. Hunt USDA/SEA-AR University of Nevada, Reno, Nev. & USDA/SEA-AR, lRAEC, Prosser, Wash.

Studies have been made of the relationship between seeding rates, plant density,and forage yield of alfalfa. seeding rate recommendations from these studies have ranged from 3 to 24 Ib/acre. Some reports have suggested a yield plateau above certain levels while others have reported increased yields with increased seeding rates. Few studies have been made of the interrelationships between seeding rates, percent establishment, plant density, canopy density, and forage yields of alfalfa.

An experiment was initiated to determine the interrelationship between seeding rates, percent stand establishment, plant density, canopy density, and forage yield of alfalfa. The experiment was established using two varieties ('Ranger', 'Lahontan') planted at four different seeding rates (4.5, 9, 18, 27kg/ha). Number of viable seeds planted and percent establish- ment after seeding was obtained. Number of plants per unit area and number of stems per unit area were obtained by destructive sampling 4 years after seeding. Forage yields were obtained during the 4 year period. Dry matter yields increased proportionally with increased seeding rates; howeve~ significant differences were found only between the 9 and 18 kg/ha seeding rates. Percent established plants decreased significantly with increased seeding rate. At the end of the fourth yea~ the 27kg/ha rate had three times more plants per unit area than the 4.5 kg/ha seeding rate. The number of stems per unit area increased only slightly between the. 4.5 and 9 kg/ha rate, but not significantly. While at all other seeding rates,the number of stems per unit area remained constant. Non-significant variety X seeding rate interactions were not obtained for all indicies tested. Although yields increased with increased seeding rate, the optimum seeding rate appeared to be between 9 and 18 kg/ha.

Forage yield of alfalfa appears to be controlled primarily by number of stems per unit area and not directly by number of plants per unit area.

Sund, J. M. and G. P. Barrington. 1976. Alfalfa Seeding Rates: Their Influence on Dry Matter Yield, Stand Density and Survival, Root Size and Forage Quality. Research Bulletin R 2786, College of Agricultural and Life Science, University of Wisconsin, Madison, Wis.

Palmer, T. P. and R. B. Wynn-Williams. 1976. Relationships Between Density and Yield of Lucerne. N. Z. Journal of Experimental Agriculture 4:71-7.

40 Effect,.!?f 1!.~_atoEides_._and FU.!l8icic:les o!l Lerom.e Establishment in Northerna Minnesota_-.. .. _

C. C. Sheaffer, D. L. Rabas, D. H. MacDonald and F. I. Frosheiser University of Minnesota St. Paul, Minn. At Grand Rapids, Minnesota, poor establishment and persistence of alfalfa (Medicago sativ~ L.) and birdsfoot trefoil (Lotu~. cornicu1atu~ L.) have been Observed with cu1tivars of varying disease resistance and winterhardiness. Soi.1 sampling indicated the presence of root-lesion (Pratylench..!!!! spp.) and pin (Paratylenchus spp.) nematodes. The root-lesion nematode has been identified as a cause of alfalfa and birdsfoot trefoil stand and yield reduction CWillis and Thompson, 1969). Willis and Thompson (1975) reported that an interaction between soil nematodes and fungi was responsible for birdsfoot trefoil yield reductions. Our objective was to determine the effect of nematocides and fungicides on alfalfa and birdsfoot trefoil es­ tablishment, yield,and persistence.

Field experiments were conducted for 2 years in which 'Ramsey' alfalfa and 'Leo I birdsfoot trefoil were established in a Cowhorn coarse-loamy sand. TWo nematocides, carbofuran (1.1 kg/ha) and fenamiphos (5.6 kg/ha) were applied to the soil and incorporated prior to legume seeding. An untreated check was also established. Nematocide application resulted in signifi­ cantly higher alfalfa and birdsfoot trefoil stands and seedling year yields compared to untreated Checks. Carbofuran and fenamiphos had similar effects on legume yields and stands. Nematocide application did not result in a significant decrease in soil nematode populations compared to the check,and no relationship existed between nematode numbers and yields.

In a subsequent study, carbofuran (1.1 kg/ha) and the fungicides benomyl (1.6 kg/ha) and metalaxyl (2.2 kg/ha) were applied alone and in combination to the soil prior to alfalfa establishment. Metalaxyl, carbofuran,and the metalaxyl-carbofuran combination resulted in highest stand counts 10 days after seeding; however, by 30 days after seeding,stand counts were greatest in the carbofuran plots. Benomyl was ineffective in reducing stand loss.

Metalaxyl is effective against Perenospora spp., ~hium spp. and Phyto­ ph thora, spp. Our results indicate a fungi-nematode interaction may be-' responsible for poor alfalfa establishment and persistence.

References

1. Willis, C. B. and L. S. Thompson. 1969. Effect of the root-lesion nematode on yield of four forage legumes under greenhouse con­ ditions. Can. J. Plant Sci. 49:505-509. 2. Willis, C. B. and L. S. Thompson. 1975. Influence ~f carbofuran and benomyl on yield and persistence of birdsfoot trefoil. Can. J. Plant Sci. 55:95-99.

41 Effects of Three Harvest Schedules on Forage Yield, Quality, and Persistence of Six Alfalfa Cultivars

Irving T. Carlson and Ike D. C. Obierika Department of Agronomy Iowa State University Ames, Iowa

The relative performance of six alfalfa cultivars varying in rate of regrowth was studied under a 3-cut and two 4-cut harvest schedules. Vernal, Valor, and 520 were slow regrowth types; Saranac was intermediate; and experimental strain 7504 and G-777 were fast regrowth types. The two 4-cut harvest schedules consisted of (a) four harvests during the period late May to 10 September at an average interval of 36 days (HS-l) and (b) four harvests during the period early June to late October with an increasing interval be­ tween harvests as the season progressed (HS-2). Under the 3-cut harvest schedule (HS-3), the first harvest was taken near June 10 and subsequent har­ vests were taken at 6-week intervals. Harvest schedules were imposed in 1977-78, and their carryover effects on winter injury, persistence and yield were determined in 1979. Percentages of crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) were determined on 1977-78 forage samples. Digestible dry matter (DDM) percentage and dry matter intake were estimated from percentages of ADF and NDF, respectively, by using prediction equations developed by the Forage Analysis Sub-committee of the American Forage and Grassland Council Hay Marketing Task Force. Their procedures also were used to determine digestible dry matter intake and relative feed value (P~). Cultivars responded differentially to harvest schedules for 1977-78 yields of dry matter, CP, and DDM~ and for 1979 winter injury rating, percentage stand, and yield of dry matter. Valor was consistently high yielding under all har­ vest schedules and G-777 and Saranac were consistently low yielding. Good stands were maintained for all cultivars under HS-3 whereas considerable stand depletion occurred in plots of Saranac, G-777, and 7504 under the other har­ vest schedules, especially HS-l. Cultivar differences for percentages of CP, ADF, and NDF were small; however, harvest schedules had major effects on these quality constituents. Forage quality was highest under HS-l and lowest under HS-3. Four harvests per year with the last harvest in late October gave the highest yields of dry matter and digestible dry matter in 1977-78. Under that harvest schedule, average RFV weighted for dry matter yield was intermediate between that of HS-l and 3; however, average 1979 stand percentage was only slightly higher than that for HS-l, the harvest schedule that gave the lowest yields. In 1979, dry matter yields were highest when the cultivars were cut three times per year in 1977-78. Although no consistent relationship was found between dry matter yield and re­ growth type, slow regrowth types were superior in persistence under management for high forage quality (liS-I).

42 Fertility and Mana~ement Practices for a 10-Ton Yield in Michigan

M.B. Tesar, Department of Crop and Soil Sciences Michigan State University, East Lansing, Mich. Alfalfa yields in the North Central US average about 3 tons hay per acre. Researchers have reported yields between 6 to 9 tons (1976 Report, Central Alfalfa Imp. Conf.),but there are no reports of 10-ton yields without irriga­ tion. The objectives of this experiment were to determine which. management or fertility practices would produce yields in the 10-ton/acre range for a Z-3 year period. Honeoye alfalfa seeded in 1976 was managed under the following practices reported earlier for maximum yields in Mich. (M.B. Tesar, 1976. Rep. Z5th Alfalfa Imp. Conf., p29): (1) 16 lbs inoculated seed/A; (2) well-drained loam of high pH; (3) 0+100+300/year; (4) 4 cuts with cut 1 in late bud, cut 2 and 3 in early flower, and cut 4 after mid-October when most regrowth has stop­ ped; and (5) weevil and leafhopper control. The soil had a pH of 7, P-55, and K-l05 lbs. Fertilizer (0+100+100) was incorporated prior to seeding. Variables were annual acre rates of 100 and 200 lbs PZ05, 0 to 1600 lbs K20, split applications of K, sources of K20, S, irrigation, and Folian (12-4-4-0.6 S) sprayed on 4-inch regrowth. Yield for a 2-year average (1978-79) are in tons/A of hay with 12% H20. Chemical composition was determined on total top growth harvested. Yields increased from 7.94 to 9.14 tons/A as annual KZO rates increased to 400 lbs. Yields were not increased with 800 to 1600 lbs KZO. Splitting K20 in the fall and spring at the 400-lb rate did not improve yields when compared to fall application (9.13 vs 9.14 T). At the 800-lb rate, splitting with 400 in the fall and 100 K20 each in spring and after cut 1, Z, and 3 yielded slightly more than when the 800 lbs were split between fall and spring (9.06 vs 8.84 T). KCl did not reduce yields compared to K2S04 at the lZOO-lb KZO rate (KCl was applied with 400 KZO each in fall, spring, and after cut 1). Cl in 1978 on top growth was 0.58% with K2S04 and 1.ZO% with KCl. PZ05 at ZOO lbs vs 100 lbs did not increase yields at the 800-lb K20 rate but may have resulted in a yield increase at the lZOO-lb rate (9.06 vs 8.84 T). Sulfur as CaS04 did not increase yields or % composition. Alfalfa averaged 3.1% N or 19.4% protein with over 500 lbs N/A in the top growth. K increased from 1.46% and 34 lbs K20/ton removed with no fertilizer to 3.03% K and 66 lbs K20/T removed at the l600-lb K20 rate. P averaged 0.30% and increased slightly as PZ05 increased; removal of PZ05 averaged lZ.4 lbs/ ton. Alfalfa irrigated with 6 inches of water and fertilized with 0+200+800 yielded nearly 10 tons/A (9.89) in 1978, a I-ton increase over non-irrigated alfalfa. In 1979, 5 inches produced a similar yield (8.76 T) compared to no irrigation (8.53 T) because of a delay in the first cut after the 1978 irrigation. Fo1ian-sprayed alfalfa fertilized with dry 0+200+1200 produced the highest annual and 2-year average yields (9.5Z T) compared to 9.Z3 T without Folian. The beneficial effect of applying Folian containing Z4 and 48 lb N per acre in 1978 and 1979 (P, K, and S were above maxima required for maximum yield) suggests that alfalfa's biological N-fixing system or the Rhizobia bacteria may need to be improved for maximum yields at high yield levels.

43 Late Autumn Harvest of Third Crop Alfalfa Can Allow Long Stand Persistence in the North G.C. Marten USDA-SEA-AR, and Department of Agronomy & Plant Genetics University of Minnesota St. Pau1, Minn. In a diverse latitude-alfalfa management study of the late 1960's, scientists in Iowa, Minnesota, Missouri, aDd Wisconsin found that during a 2-year period, alfalfa yields of dry matter, digestible dry matter, and crude protein in­ creased as the number of cuttings of 'Vernal' and 'DuPuits' increased from two to four per season in all states except Iowa. However, by the third year in Minnesota and Wisconsin, the fourth cutting in October caused a weakening of stands and yield depression. Therefore, we recommended that the established 3-cut system (first flower-first flower-no later than September 6) was optimum to insure best persistence and highest long-term yields of feed nutrients. A problem with the recommended 3-cut system is that farmers cannot always harvest the third crop of alfalfa by the first week of September because of unpredictable weather. Also, Yager and Tesar (1968) in Michigan suggested that the strict recommendations of not cutting alfalfa in September or early October in many states needed to be reexamined. We harvested the first and second crops of Vernal alfalfa at first flower followed by third crop harvest at the three dates shown below in each of 3 years. At least 300 lb exchangeable K/A and 50 1b available PIA were main­ tained in the well-drained silt-loam soil during the study (pH of 6.7). Snow­ cover during the coldest parts of the winters ranged from 4 to 12 inches. We harvested either all three crops at 7 cm or 14 cm or the first and second crops at 7 cm and the third crop at 14 cm. Neither cutting height nor date of cutting the third crop affected total year crude protein concentration (18%) or in vitro digestibility (68%) of the alfalfa dry matter. Also, hay yie1ds1Were not influenced by cutting schedules: Date of cutting Hay yield third crop (tons/acre) 8/26 to 9/3 4.11 9/15 to 9/19 4.12 9/30 to 10/15 4.16 However, cutting all three crops to ~eave a 14-c~ stubble ~aused a 9~ yield decrease. Differences in date or helght of cuttlng the thlrd crop dld not affect alfalfa stands which were close to 100% after 4 years. We conclude that harvest of the third crop of alfalfa during September or early October can allow long stand persistence in our environment provided soil fertility is adequate, winterhardy varieties are planted, and adequate snow cover prevails. More research is needed to determine whether these results are repeatable with other varieties in other e~vironments a~d whether harvest of a fourth crop during September or October wlll allow optlmum 10ng­ term yields and persistence with the newer productive varieties.

44 Reproduction of Alfalfa in a Dryland Pasture

M. D. Rumbaugh USDA/SEA-AR Utah State University Logan, Utah

Semiarid range improvement practices must have long lasting effects if they are to be economically feasible. Plant materials used in seeding operations need to be long lived or have the ability to reproduce and re-establish them­ selves. Alfalfa is known to be a long-lived legume~but its capability 'for reproduction and re-establishment on rangeland has not been documented.

Eight populations were seeded near Snowville, Utah, on May 20, 1954. The test site had been used for winter wheat and was reverting to dry1and pasture. Precipitation 2 km from the experiment averages 28 cm annually. Elevation is 1,420 m and soils are of the Xerollic Haplargids-Xerollic Calciorthids Association. 'Grimm', 'Ladak', 'Nomad', 'Ranger', 'Rhizoma', 'Sevelra', Utah Common, and Medicago faZcata were sown in an unreplicated planting. of 122 m X 76.2 m plots. The field was used as early spring pasture for cattle each year after establishment. Animals were removed prior to June. Data were obtained from 10 randomly placed 30.5 X 61.0 cm sampling frames for each population in the spring and fall of 1977-1979. All mature plants in the experiment were counted in 1977. Plants were dug for crown diameter measurement and age classification in 1977.

Seed production for the 3 years, 1977-1979, averaged 141 seeds per square meter with no significant differences among the populations. This is the equivalent of 1,410,000 seeds per ha. An average of 103,000 seedlings per ha were counted in the springs of 3 years. Twelve percent survived to the fall of the year in which the seed germinated. Based upon above ground morphology, the equivalent of 7,220 young plants and approximately 26,000 mature plants per ha were counted. Plants were dug up in 1977 and.classified as "young" or "mature" on the basis of diameter and shape of the crowns and root cortex color and texture. Seven percent of the 387 plants were con­ sidered to be young. All mature plants were diseased with root and crown rot. This appeared to be the major cause of mortality. The age class ratios based on both above- and below-ground morphology were considered to be evidence that all eight of these alfa~fa populations were able to repro­ duce and re-establish themselves in sufficient numbers to maintain plant· densities suitable to optimize forage production for spring grazing in the test environment.

Reference

Rumbaugh, M. D., and M. W. Pedersen. 1979. Survival of alfalfa in five semiarid range seedings. J. Range l-1anage. 32:48-51.

45 Alfalfa ~1anagement Research in Nevada

E.H. Jensen, Agronomist Nevada Agricultural Experiment Station University of Nevada-Reno

Alfalfa is Nevada's most important agronomic crop, with approximately 35% of the irrigated acreage in the state devoted to it. Results of some of our ex­ periments that have recently been completed or are nearing completion are presented below.

EFFECT OF WINDROWS ON ALFALFA REGROWTH AND YIELD: Windrows reduced alfalfa regrowth a~d yield. The regrowth after harvest was delayed more where large windrows were left for more than 4 days. In the absence of weeds, wind­ rows.reduced regrowth approximately in proportion to the duration of light ex­ clusion to the regrowth. Stand density decreased at a higher rate where wind­ rose were left in place for 8 days. Alfalfa yields were reduced by as much as 25% in the area covered by windrows for 8 days. Removal by wind- rows as soon as the hay can be baled may increase alfalfa yields by as much as 10% in four harvests per year.

EFFECT OF WHEEL TRAFFIC DURING HARVESTING ON ALFALFA YIELDS: Ten cultivars were seeded in mid-August 1976 and grown under irrigation. A fully loaded automatic bale wagon weighing approximately 9 metric tons was driven over the plots after the initial cutting in 1977 and all subsequent cuttings 1977-79. Wheel traffic on alfalfa 1 and 7 days after harvest caused a reduction of 12 and 31, 4 and 24, 5 and 25% for harvest years 1977, 1978, and 1979, re­ spectively. The 10 cultivars tested reacted similarly to the traffic treat­ ments. It is advisable to bale and remove the hay as soon as feasible after cutting to minimize wheel traffic damage.

DORMANT SEASON GRAZING OF ALFALFA: At Reno, during 1975-79, cattle grazed alfalfa (cv. Lahontan) during November, January,or April. Adjacent plots were harvested at the same time plus a harvest in early May. Dormant season grazing or defoliation did not reduce forage yields during the 4 years the trial was conducted. Thus, farmers could graze aftermath and obtain an addi­ tional one-half ton or more of forage per acre without a reduction in summer yields. Defoliation in May when the alfalfa was 3 to 5 inches tall reduced summer yields. APPLIED WATER USE EFFICIENCY OF ALFALFA: This study was conducted at the Central Nevada Field Laboratory at Austin, Nevada. In 1978, alfalfa irrigated at 98 and 84% of pan evaporation yielded significantly more than alfalfa irri­ gated at 28 or 63% of pan evaporation. Total water applied during the growing season prior to the last harvest in August was 30, 63, 9l,and 107 cm where irrigated at 28, 63, 84, or 98% of pan evaporation, respectively. Application of water equal to 63% of pan evaporation gave significantly higher amounts of forage per unit of water applied than any other treatment. In 1979 alfa~fa watered at 72% of pan evaporation had the higher yields and highest app11ed water use efficiency. The interaction of alfalfa cultivars times ~rrigation regimes was not significant. Phosphate fertilization did not sign1ficantly affect yield or applied water use efficiency.

46 Pennsylvania's Alfalfa Growers Program - A Field study

J. E. Baylor Department of Agronomy The Pennsylvania State University University Park, Pa.

Over the past 3 years, more than 150 alfalfa growers in Pennsqlvania completed all of the requirements in a competitive alfalfa growing program. Its purpose, to measure just how much alfalfa hay, protein,and energy an acre of Pennsylvania land will produce, to determine the mineral nutrients removed by high yielding crops, and at the same time to develop more reliable on-the­ farm data on alfalfa production costs.

Yields were measured by cuttings from the windrow of a selected 5-acre block using a special measuring device designed for the Pennsylvania Forage and Grassland Council. Quality data included crude protein, ADF, TDN, and a complete mineral analysis. Per acre yields of protein and TDN were calculated as was nutrient removal for all major elements. Cost of production data for 1977 and 1978 has been summerized.

Hay equivalent yields per acre over the 3 years averaged 5.5, 5.5, and 5.8 tons, respectively. The range in yield for each of the 3 years was 1977-3.3 to 8.1 tons; 1978-3.0 to 8.7 tons; 1979-3.8 to 9.1 tons. The top grower in each of the 3 years had estimated yields of H.E., CP,and TDN as follows: H.E.(T/A) CP(lbs/A) TDN(lbs/A) 1977 8.1 3133 9,300 1978 8.7 3268 9,700 1979 9.1 3480 10,400 Nutrient removal per acre for P205 averaged 69, 78,and 91 pounds per acre, only slightly above normally established removal values for similar average yields. Removal of K20 per acre over the 3 years ranged as follows: 1977, 150 to 500 pounds; 1978,174 to 629 pounds, 1979,240 to 668 pounds. Average removal per acre for each of the 3 years was 347, 368, and 397 pounds, respectively, with removal per ton approaching 68 pounds.

Cost of production data for 1977 and 1978 participants was sUlnmarized by W.K. rvaters, Associate Professor of Farm Management Extension. Briefly the total annual cost per acre for growing and harvesting alfalfa was $173 to $190 very similar to the. per acre costs for corn as determined from summaries of the 5-Acre Corn Club. Machine costs, fertilizer, the land charge,and labor accounted for nearly 87% of the total cost. The average annual per acre seed bill on these farms was $7.00, nearly 4% of the total cost.

Original establishment costs totaled nearly $103.00 per acre each year. When prorated over the estimated stand life (4.8 years) the annual establishment cost totaled $21.00 per acre.

10 help offset some of the costs an entry fee of $50 was paid by each participant with many growers sponsored or co-sponsored by a local seedsman or fertilizer dealer.

47 Forage Yields from Different Patterns of Initial Stands

Jonas W. Miller Department of Alfalfa Breeding Pioneer Hi-Bred International, Inc. Johnston, Iowa

Adjusting forage yields to the amount of initial stand in multiple-rowed plots has not been a common practice among alfalfa breeders. Kramer and Davis found a correlation between yield and stand for the first two har­ vest years, when using 6-inch blank (15.24 em) spaces in plot rows as the basis for determining stand. This study takes into account initial stand differences only.

The alfalfa cultivar, 520, was seeded in forage yield test plots of five rows, 15.24 em apart within the plot and I-foot spacing between plots. The final plot size was .91 m X 6.1 m and was seeded at the rate of 13.5 Kg/ha. The experiment consisted of nine treatments with four replications. Five weeks after seeding, the stand treatments were imposed upon the plots at random. Stands were reduced to 80 and 90 percent by hoeing out por­ tions of the plot~ in patterns shown in Figure 1. Two plantings were made, one in April of 1975 and a second one in April of 1977. Four cuttings were made each year, and forage yields were determined by estimating the green weight to be 22.5% dry matter.

Figure 1

I I A B C E F G H I

Treatment Treatment Treatment

A - Full Stand D 1 Row, l' Units G - ~ Row, Edge B 1 Row, Edge E - 1 Row, 2' Units H - ~Row, Center C - 1 Row, Center F 1 Row, 3' Units I - ~ Row, l' Units

48 Pertinent data on forage yields are presented in Table 1. Significant differences in yields were found among treatments in the second plant­ ing. Statistical calculations were not made for the first planting, but they appear to be similar to the results from the second test. The greatest reduction in forage yields were found in treatments Band G and were in direct proportion to the loss in stand. In both of these treatments, the reduced stand was the loss of a row on the edge of the plot. Treatments C and H, where all and half of the center row was miss­ ing, produced forage yields that fully compensated for the loss of·stand by producing forage yields that were nearly equal to treatment A, which was a full stand. The other treatments showed no significant reduction in forage yields over the 2 years.

Table l.--Average forage y.ield for two plantings percent of average of the experiment

510421 710421 Average Treatments 2 Yr Avg 2 Yr Avg Over Loc

A 104% 103% 103.4% B 91 97 93.7 C 106 101 103.4 D 99 101 100.0 E 97 101 98.6 F 99 101 99.8 G 98 98 97.7 H 104 99 10~.5 I 10J 101 102.0

Kg/ha 16,056 15,517 15,783

CV 4.7% LSD (.05) 3.9%

Problems of stand establishment seldom affect more than one replication of an entry. In those instances where one replication has 20% of the stand not established, the resulting forage yield when averaged with the other three replications should not produce a significantly lower forage yield. Cultivars with good forage yielding potential should compensate for stand establishment problems without having to make any adjustment in forage yield.

References

1. Kramer, H.H. and R.L. Davis. 1949. The effect of stand and moisture content on computed yields of alfalfa. Agronomy Journal 41:470-473.

49 Glandular Secretory System of Annual and Perennial Medicago Species G. L. Kreitner and E. L. Sorensen Department of Agronomy and USDA-SEA-AR Kansas State University Manhattan, Kans.

We studied the structure and functional secretory activities of glandular tri­ chomes on annual and perennial Medicago species us.ing light microscopy, scan­ ning electron microscopy (SEM), and transmission electron microscopy (TEM), and found two kinds of glands among the species studied. Small procumbent glands composed of few cells were typically the only kind appearing on diploid and tetraploid M. sativa sativa. Other glands that stand erect on the plant surface are composed of numerous head cells and a multicellular stalk (capitate-stalked). Erect glands outnumber procumbent glands on the diploid and tetraploid annual species we observed. Our studies revealed erect and procumbent glands also on the vegetative parts of a tetraploid perennial, M. sativa praefalcata~ and a diploid perennial, M. prostrata. Both procumbent and erect glands exhibit secretory activity.

Procumbent glands produce only a small amount of secretion, which tends to become dry and hard. The ultrastructure of secreting cells shows that dictyo­ somes are numerous and actively proliferating vesicles, suggesting that carbo­ hydrates are a major component. Small amounts of sudanophilic lipids can be detected in the secretion. Procumbent glands are not known to deter or resist insect predators of alfalfa.

Erect, capitate-stalked glands produce copious secretions, apparently on an intermittent basis during the life of the shoot. The secretion either dries less than that from procumbent glands or a fresh supply is frequently added. Sudan staining indicates that lipids are a prominent component. Erect glands on annual species have been implicated in very high resistance to predatory larvae of the alfalfa weevil.

Ultrastructural studies show that secretory-cell plastids are a probable origin of material secreted by erect glands. In all instances, the plastids show the small-diameter tubules of chromoplasts. We are unaware of other studies link­ ing chromoplasts and secretion.

In M. sautellata and M. sativa praefalcata chromoplasts pass into the cytoplasm pre-secretion substances, which are transformed into osmiophilic material in the vacuolar system. This material is presumed to be an intermediate stage in secretion formation. In M. prostrata~ whole chromoplasts are incorporated into vacuoles via investing endoplasmic reticulum. Final secretion collects under the cuticle on the gland head before emerging to the surface.

Erect glands were sparse on the vegetative parts of M. sativa praefalcata. Two cycles of selection have increased their numbers to approximately that on plants of M. sautellata. Selection also has increased the amount of osmio­ philic material accumulating in the vacuolar system of secretory cells. Secreting capacity of these selected strains, though improved, remains lower than that of M. sautellata.

50 Resistance to Alfalfa Weevil and Potato Leafhopper Increased by Glandular and Simple Hairs

E. K. Horber, E. L. Sorensen, and K. J. R. Johnson Departments of Entomology, Agronomy, and USDA-SEA-AR Kansas State University Manhattan, Kans.

In growth chamber tests, annual glandular-haired tetraploids, Mediaago pugosa and M. sautellata were highly resistant to alfalfa weevil larvae, Hypera postiaa at each of three temperatures (17, 22, 28 C). Larval mortality was complete during the first instar. Although the diploids (M. blanaheana and M. disaiformis) were less resistant than the tetraploid annuals, they caused consistent larval mortality at all three temperatures.

The glandular-haired annual species were more resistant than M. sativa cultivars (Arc and Lahontan) to adult weevil feeding in free-choice tests with attached or excised leaves and attached stem terminals. Measured by the number of weevils visiting plants in stem terminal free-choice tests, M. sativa cultivars were more attractive than the annual species.

In no-choice and free-choice tests, adult weevils reared on M. sativa laid fewer eggs in stems of M. blanaheana, M. rugosa, and M. sautellata, than in stems of M. sativa. Results were similar in no-choice tests when weevils were reared from eclosion on the test species.

Perennial glandular-haired diploid M. prostrata plants tested only at 22 C were resistant to alfalfa weevil larvae. No larvae survived to maturity. They fed little, moved often, and gradually dehydrated. In a preliminary test at the same temperature, about 15% of the larvae died on a perennial glandular-haired tetraploid M. sativa subsp. praefalaata plant (7-30); in a greenhouse test, no first instar larvae survived.

In laboratory tests of alfalfa terminals from plants in the field, repro­ ductive adult alfalfa weevils caused less damage to M. sativa cultivar San Pedro plants with a high density of simple hairs than to those with low density hairs. Lahontan (very few simple hairs) was severely damaged. oviposition into field-grown stem terminals of M. sativa did not differ significantly between plants with high than those with low density simple hairs.

Potato leafhoppers caused no visible damage to perennial glandular-haired M. sativa subsp. praefalaata plants in replicated field trials where non­ glandular-haired plants from the same population and the cultivar Lahontan wcre damagcd. Resistance to yellowing caused by the potato leafhopper to M. sativa (San Pedro) plants increased directly with density of simple hairs.

5 The Chemical Identification of the Glandular

Hair Exudate from Mediaago scuteZZata

Donna C. °Triebe C. E. Meloan E. L. Sorensen Department of Chemistry Department of Chemistry USDA, SEA, AR Kansas state University Kansas State University Department of Agronomy Manhattan, Kansas 66506 Manhattan, Kansas 66506 Kansas State University Manhattan, Kansas 66506

One of the authors (Sorensen) noticed that certain annual Mediaagos that have erect glandular hairs on stems and leaves were resistant to alfalfa weevils. Microscopic examination of the glands indicated dead weevil larvae attached to the top of the hairs. The hairs were observed to form an exudate that apparently killed the weevils by some mechanism.

This paper reports on the separation and identification of several of the compounds in the exudate. Some previous work had been done by Campbell, Shade, and Thompson at Purdue University several years ago. Their results indicated the presence of long chain hydrocarbons.

A glass rod, etched with HF, was rolled over the stems of Mediaago sauteZZata to remove the exudate and minimize contamination from the rest of the plant. This exudate was dissolved in CHC1 and concentrated. 3 The exudate concentrate was separated into 20 components with a 6', l/S", SS column containing 3% OV-lOl on acid washed chromosorb-W, SO-IOO mesh. The temperature was programmed at 10o/min over the range l50~300oC. A N2 flow rate of 30 ml/min was maintained.

Mass spectral data were obtained using either a Finnegan Model 4023 or an AEI MS 5076 mass spectrometer.

The five major compounds consist of a C-2l ketone, a C-20 ester with one double bond, a C-20 diene, a C-16 monoene, and a C-16 diene.

The structures of these compounds will be presented along with some of the minor concentration compounds and a suggested mechanism of how they affect weevil larvae.

52 Transfer of Glandular Hairs from Diploid Mediaago prostrata to Tetraploid M. sativa

E. L. Sorensen, N. Sangduen, and G. H. Liang Department of Agronomy and USDA-SEA-AR Kansas State University Manhattan, Kans.

Mediaago falaata and M. sativa have been the most widely used species in 2x - 4x and reciprocal crosses. Generally, 5 to 15 hybrid progeny were produced per 1000 diploid-tetraploid or reciprocal crosses. The progeny were usually all tetraploid in 2x - 4x and triploid or tetraploid in 4x - 2x crosses. Tetraploids were produced when gametes with the unreduced chromosome number (2n gametes) from the diploid parent united with reduced gametes from the tetraploid. Triploids were produced when reduced gametes from each parent united (1).

We crossed a diploid glandular-haired M. prostrata plant with tetraploid M. sativa Chilean and nondormant types. In 2x - 4x crosses, 5 and 49 hybrid progeny per 1000 crosses were produced by the Chilean and nondormant types, respectively. Reciprocal crosses of the nondormant type produced 32.

All hybr~d plants produced from 2x - 4x crosses were tetraploid. Reciprocal crosses involving Qnly the nondormant type produced 1 hexaploid, 17 tetra­ ploids, and 1 triploid plant. The hexaploid probably was produced from the union of 2n gametes from each parent. Germination of stainable pollen was 37 and 49 percent for the triploid and hexaploid, respectively. Self fertility was low at both ploidy levels (3x = 4 and 6x = 5 seeds per 100 selfed florets). The triploid and hexaploid set more pods in crosses with tetraploids (3x = 78 and 6x = 60 per 100 crosses) than with diploids (3x = 14, 6x = 7).

The hybrid tetraploid plants we studied showed little abnormal chromosome behavior at metaphase I. Bivalent associations predominated. The plants were fertile, sterility problems minor. All F plants had glandular hairs but on the vegetative parts the hairs were spa!se and usually confined to stipules and leaflets. The tetraploid hybrids were intercrossed and cyclic selection was used to increase frequency and distribution of glandular hairs before backcrossing to M. sativa germplasm.

References

1. Stanford, E. H., W. M. Clement, Jr., and E. T. Bingham. 1972. Cytology and evolution of the Mediaago sativa falaata complex. p. 87-101. In C. H. Hansen, [ed.], Alfalfa Science and Technology, Am. Soc. Agron., Madison, WI.

53 Factors Affecting Yield and Quality of Alfalfa Sprouts

o. B. Hesterman and L. R. Teuber Agrono~y and Range Science University of California, Davis

Consumption of germinated alfalfa (l~dicago sativa L.) seed (sprouts) in salads and sandwiches is rapidly increasing-thr~ughout the United States. Sprouted alfalfa seed has become one of the most cor:unercially important sprouts. In 1970 the alfalfa sprout industry in California consumed approximately 50,000 lbs of alfalfa seed. It is now consuming more than 1.5 million lbs of alfalfa seed a year with an estimated value for the sprouts of oore than 8.5 million dollars. Sprouts may be a significant source of nutrients, including protein (Kylen and llcCready, 1975) and ascorbic acid (Hamilton and Vanderstoep, 1979). Seed characteristics that are important in sprouting are high percentage Bermination, low percentage hard seed, and high seedline vigor. Methods for growing sprouts are nearly as varied as the number of 3rowers. \Ie undertook an investigation to determine the effect of environoent and genotype on the fresh-weight yield and quality of alfalfa sprouts. Six alfalfa cultivars representing a broad range in fall dor~ancy were germinated under varying environmental conditions including temperature, light duration, a~ount and frequency of water application, and number of days to harvest. Sprouts were analyzed for fresh weight yield and percent­ age protein (as a measure of nutritional quality). Significant differences were found among cultivars and among environ­ ments for fresh weight and percentage protein of alfalfa sprouts. Our data suggest that non-dormant cultivars will produce greater fresh-weight yields but a lower percentage protein than dormant cultivars. Percentage protein of the sprouts neasured on a dry weight basis was greater than the percentage protein in the ungerminated seed. Total protein, however, decreased as the seed sprouted. Based on these studies we recommended optimum environments for producing sprouts of either high percentage protein or high fresh weight (Hesterman and Teuber, 1979).

References

1. Hamilton, lIe J., and J. Vanderstoep. 1979. Germination and nutrient composition of alfalfa seeds. J. Food Sci. 44:443-445. 2. Hesterrnan, o. B. and L. R. Teuber. 1979. Alfalfa sprouts: methods of production, current research, and econolnic importance. Proceedings, Ninth California Alfalfa Symposium. pp. 24-27. 3. Kylen, A. 11. and R. U. l1cCready. 1975. Nutrients in seeds and sprouts of alfalfa, lentils, mung beans, and soybeans. J. Food Sci. 40:1008-1009.

54 An Overview of Legume, Pasture Bloat Research at Saskatoon

R. E. Howarth, G. L. Lees and B. P. Goplen Agriculture Canada, Research Station Saskatoon, Saskatchewan, Canada

Our program to breed a bloat-safe alfalfa cultivar has been greatly influenced by the concept that plant cell rupture by chewing and the initial rate of microbial digestion are important events in the occurrence of pasture bloat. Selections for high and low initial rates of microbial digestion are in progress using a modified nylon bag technique with fistulated cattle. The development of techniques for assessing resistance to mechanical rupture in alfalfa herbage has been slow, but we now have a method based on sonication of whole leaves (2). Soluble protein, our original selection technique, has been continued in the second generation, but selection for slower rates of digestion and/or greater resistance to mechanical rupture are better approaches for development of a bloat-safe alfalfa.

An extensive search for condensed tannins has been conducted in 2n Medicago falcata and 4n~. sativa treated with mutagens, 34 annual Medicago species, 28 perennial Medicago species, and 31 Trigonella species (1). All tests for tannins in the leaves are negative. Tannins are present in the seed-coat of alfalfa except in a homozygous, recessive white-seeded strain. Thus the genetic mechanism for tannin production exists in alf~lfa, but a means of turning on the gene(s) at an earlier ontological stage is still a major hurdle to introducing tannins into alfalfa forage.

Research into the causes of alfalfa pasture bloat has continued along several lines of investigation. A study of the bloat incidence in cattle fed high- and low-saponin strains of Ranger alfalfa (3) showed no difference in bloat incidence between the two near-isogenic strains, thus indicating that saponins are not likely involved as causative agents in pasture bloat.

References

1. Goplen, B. P., R. E. Howarth, S. K. Sarkar and K. Lesins. 1980. ~ s:arch for. condensed tannins in annual and perennial species of Med1cago, Tr1gonella, and Onobrychis. Crop Sci~ 20:ROl-84.

2. Lees, G. L., R. E. Howarth, B. P. Gop1en and A. C. Fesser. 1980. Mechanical disruption of leaf tissue and cells in bloat-causing and bloat-safe forage legumes. Ms. submitted to Crop Sci. 3. Majak, W., R. E. Howarth, A. C. Fesser, B. P. Goplen and M. W. Pedersen. 1980. Relationships between ruminant bloat and the composition of alfalfa herbage. II. Saponins. Ms. submitted to Can. J. Anim. Sci.

55 Selection for Phosphorus and Lignin Content in Alfalfa

R. R. Hill, Jr. USDA/SEA/AR U.S. Regional Pasture Research Laboratory University Park, Pa.

Sixty full-sib families were produced by chain-crossing a random sample of plants from Beltsville 2-An4 (Devine et al., 1973) alfalfa. Seeds from these crosses were established in row plots at the Rock Springs Research Center in the spring of 1977. High-phosphorus, low-phosphorus, high-lignin, and low­ lignin selections were made on the basis of concentrations in first harvest forage in the spring of 1978. Each group was represented by the six highest or six lowest families for the appropriate trait.

Phosphorus concentration averaged 0.37% for all families, 0.40% for the high selections, and 0.31% for the low selections. High-phosphorus selections tended to have greater protein and lower fiber concentrations than did the low selections. Average yield of the low-phosphorus selections was signifi­ cantly greater than that of the high selections. The low-phosphorus selections deviated from the population mean more than the high-phosphorus selections. Yield of phosphorus (concentration times forage yield) did not differ for the high- and low-phosphorus selections. Yield of lignin (concentration times forage yield) was less for the low-phosphorus than for the high-phosphorus selections.

Lignin concentration averaged 9.90% for all families, 10.87% for the high­ selections, and 8.93% for the low-selections. Yield of the high-lignin selections was significantly greater than that of the low-lignin selections. The deviation from the population mean was greater for the low-lignin than for the high-lignin selections. Yield of phosphorus and yield of lignin was significantly less for the low-lignin than for the high-lignin selections.

Previous research in germplasm related to that of the present study indicated that genotypic correlations for yield with phosphorus and lignin concentra­ tions were not significant (Hill and Barnes, 1977). Correlated responses when selection was practiced for phosphorus and lignin concentrations were greater than the estimated genotypic correlations indicated they would be. Alfalfa breeders cannot ignore agronomic performance, even for one or two cycles of selection, when breeding for imp~oved quality of alfalfa.

References

1. Devine, T. E., C. H. Hanson, S. A. Ostazeski, and O. J. Hunt. 1973. Registration of alfalfa germplasm (Reg. Nos. GP17 to 21). Crop Sci. 13:289. 2. Hill, R. R., Jr., and R. F. Barnes. 1977. Genetic variability for chemical composition of alfalfa. II. Yield and traits associated with digestibility. Crop Sci. 17:948-952.

56 Changes In the Cold Hardiness of Alfalfa (Medicaso falcata) During Five Consecutive Winters In Northern Alberta J.S. McKenzie Agriculture Canada Research Station Beaverlodge, Alberta Winter injury is a major problem of alfalfa production in northern Alberta. Although widespread Injury has been reported only five times in the last 60 years, rarely Is there a year in which some Injury does not occur some­ where in the region. In addition, vigorous production seldom continues In anyone field for more than four years. Winter Injury cannot always be predicted because environmental stress Is a relatively unpredictable variable that differs from year to year and from site to site. Environmental conditions can also influence the physiological status of a plant and limit or prevent development of adequate cold tolerance. This suggests that some plants may be more susceptible to stress from environmental conditions not normally conducive to injury. The objective of this study was to evaluate the relative changes In cold hardiness of a seed plot of M. falcata cv. Anlk during five consecutIve winters at 8eaverlodge, Alberta, In order to identify some of the environ­ mental condltlon~ which may Influence cold hardiness In this region. Anik Is the most persistent alfalfa cultivar In northwestern Canada, but it can be affected by winter stress (I). Plants were collected from the field during the fall, wlnter,and spring periods of 1974-75 to 1978-79 and subjected to artificial freezing tests to evaluate their relative changes In cold hardiness. The study concluded that Antk alfalfa starts to harden in mid-September, attains Its maximum cold hardiness level shortly after the soil surface remains permanently frozen In the fal',and dehardens In the spring in response to rising soil temperatures. However, the most significant aspect of this study was that the hardiness of these plants can change from year to year depending upon environmental conditIons In the fall. For example, a late flush of growth In the fall can delay hardenIng. Similarly, water saturated soil can deharden the plants after hardening has commenced. Both of these conditions can significantly reduce the mid-winter cold hardiness level. Furthermore, In the spring plants may begin dehardenlng before soil temperatures increase. This study adds further insight Into climatological stUdies (2),whlch suggest that alfalfa survival depends upon the plant's response to climatic factors during critical phases of Its life cycle. References I. McKenzie, J.S. and G.E. McLean 1980. Some factors associated with Injury to alfalfa during the 1977-78 wInter at Beaverlodge, Alberta. Can. J. Plant Sci. 60:103-112. 2. QuelJet, C.E. 1977. Monthly climatic contribution to the winter Injury of alfalfa. Can. J. Plant Sci. 57: 419-426.

57 Use of Strain Crosses in Breeding Multiple Pest Resistant Alfalfa

J. H. Elgin, Jr. Science and Education Administration, USDA, Beltsville Agricultural Research Center Beltsville, Md. Alfalfa forage production is seldom limited by one nematode, insect, or disease pest, but more typically, by a collection of multiple pest problems. Alfalfa breeders have been very successful in developing high levels of resistance to numerous pests in the last 50 years, however, few germplasms or cultivars have resistance to more than one or owo pests. Consequently, forage production falls short of what it might be with resistance to a range of pest problems.

What is needed are alfalfas with multiple pest resistance (MPR). Theoretically, the cross of two strains with high dominantly inherited resistance to two different pests would result in a population with moderate resistance to both pests. Thus, producing strain crosses among the presently available germplasm with high dominantly inherited resistance to several differing pests is a logical first step in the development of MPR populations. To evaluate advantages of the strain cross technique,six MPR populations were produced at Beltsville,Md.,and Reno, Nev~, using strain crosses and increased to the Syn 4 generation (equivalent to certified seed). Each population was synthesized with controlled pollinations between 100 plants from each of two parent strains. MSACW3An3, MSBCW5An3, Dawson, Belts. 2-An4, Arc, and Nev. Syn XX were used as the parent strains. Evaluations of the Syn 1 to Syn 4 generations of the MPR populations were made for resistance to anthracnose, bacterial wilt, common leafspot, rust, root-knot nematode, stem nematode, pea aphid, spotted alfalfa aphid, potato leafhopper yellowing, and for fall dormancy ratings. Forage yields were obtained for the Syn 2 to Syn 4 over 3 years. As expected, in most cases the data revealed a tendency for the pest resistance and dormancy of all six populations to be near the mid parent of the two parental strains. For example, crosses between strains with high level resistance (e.g. 80%) and low level resistance (e.g. 10%) to a given pest resulted in a population with resistance between 40$ and 50%. Only an occasional indication of a reduction in the pest resistance or dormancy levels of the populations with increasing synthetic generation was found. Forage yields of the populations tended to exceed slightly (although not significantly so) those of the best parent strain (heterosis) and remained generally stable from the Syn 2 to Syn 4. The production of numerous MPR populations and cultivars via strain crosses is foreseen in the coming decade.

58 Field Selection for Phytophthora Resistance in Aphid Resistant Alfalfa Populations

w. R. Kehr, D. K. Barnes, F. I. Frosheiser, and G. R. Manglitz Agricultural Research, Science and Education Administration, USDA University of Nebraska, Lincoln, Nebraska, and University of Minnesota, St. Paul, Minnesota

Multiple pest resistant alfalfa (Medicago sativa L.) populations were developed at the Nebraska station through several cycles of selection within materials of genetically diverse origin. The populations are winterhardy and have various levels of combined resistance to bacterial wilt (Corynebacterium insidiosum (McCull) H. L. Jens), pea aphid (PA) [Acyrthosiphon pisum (Harris)], spotted alfalfa aphid (SAA) [Therioaphis maculata (Buckton)], downey mildew (Peronospora trifoliorum de Bary), potato leafhopper yellowing (Empoasca fabae (Harris)], anthracnose (Colletotrichum trifolii Bain), and alfalfa weevil [Hypera postica (Gyllenhal»). As other pests were identified, populations were cooperatively evaluated with other stations to determine resistance.

A cooperative program to increase levels of resistance to Phytophthora root rot (PRR) (Phytophthora·megasperma Drechs.) by phenotypic recurrent selection was initiated with the Minnesota station in 1971. Seed was sown in the spring in a field nursery where an epiphytotic was produced. The first cycle of selection was made in the Syn-2 generation. In September, plants were dug and the roots visually examined and scored for root. rot severity. Plants with root scores of I and 2 (on a 1-6 scale, where 1 = no disease and 6 = dead plant) were considered resistant. Data were expressed as percentages of plants with scores land 2, and as average severity indices. From 100 to 215 resis­ tant plants per populations were mailed to Lincoln. From 100 to 200 plants were intercrossed by hand at random within popUlations to produce the PRRI Syn-l (Pl). The second cycle of selection was made in either the PI Syn-l or Syn-2. The Syn-2 generations of the original, PI and P2 populations were compared for PRR resistance in field tests and for PA and SAA resistance in greenhouse tests using standard procedures.

The original populations N.S. 72, 78, 79, and 82 had low levels of PRR resis­ tance. The percentages of resistant plants were as follows: from 4 to 12% in the original populations; 13 to 17% after one cycle (PI) of selection; 28 to 64% after two cycles (P2) of selection, compared with 34 to 46% for 'Agate' and 2 to 5% for 'Saranac', the resistant and susceptible checks, respectively. Average severity indices varied from 3.7 to 4.2 in the original populations; 3.0 to 3.6 in Pl and 2.6 to 3.0 in P2 populations, compared with 2.9 to 3.0 for Agate and 4.5 to 4.7 for Saranac. Thus, 2 cycles of selection in each of 4 populations were effective in increasing PRR resistance to economically important levels.

The percentages of plants resistant to PA and SAA were the same in the original population and in related populations derived from two cycles of selection for PRR resistance.

!( Published as Abstract No. 80-1402, Abstract Series, Nebraska Agricultural Experiment Station.

59 Self- and Cross-fertility in Alfalfa Populations Before and After Selection for Pest Resistance !!

J. A. Rodriguez and W. R. Kehr Agricultural Research, Science and Education Administration, USDA University of Nebraska, Lincoln, Nebraska

Alfalfa (Medicago sativa L.) varieties with multiple pest resistance are devel­ oped through recurrent phenotypic selection. The potential for shifts through random drift, inbreeding, or correlated responses in other characters when selecting for pest resistance remains a possibility.

This study was designed to determine the effects of recurrent selection for pest resistance in alfalfa populations on self- and cross-fertility. Two cycles of recurrent selection for resistance to stem nematode (SN2) (Ditylenchus dipsaci [Kuhn] Filipjev) and anthracnose (AN2) (Colletotrichum trifolii Bain) were made at Reno, Nev., on Nebraska population N.S. 78 to produce the derived population N.S. 78 SN2 AN2. The same procedure was followed at Beltsville, Md., to produce N.S. 79 AN2 from the original population N.S. 79. Two cycles of recurrent selection for resistance to phytophthora root rot (P2) (Phytophthora megasperma Drechs.) were made at st. Paul, Minn., on Nebraska N.S. 82 to produce N.S. 82 P2. These selection programs resulted in levels of resistance comparable to resistant check varieties. In every cycle of selec­ tion and/or generation of synthesis more than 75 plants were used.

About 80 plants of each Syn-2 generation were used in self- and cross­ fertility studies in the greenhouse. Fifty-two to 71 flowers/plant were self­ pollinated, and 21 to 22 flowers/plant of 'Paine INTA' were cross-pollinated as the tester population. Number of flowers selfed or crossed, and number of pods and seed obtained were recorded on an individual plant basis. Compar­ isons were made between the respective original and derived populations. For this presentation, only the seeds/flower indices are considered. The experi­ mental designs were randomized complete block with 4 replications of about 20 plants each. Pollination days were replications.

No changes in self- or cross-fertility were observed in comparisons of the original N.S. 79 Syn-2 population with the derived N.S. 79 AN2 Syn-2. Signif­ icant decreases in both self- and cross-fertility levels were found in N.S. 78 SN2 AN2 Syn-2 compared with the original N.S. 78 Syn-2 population. On the contrary, both self- and cross-fertility levels were significantly increased in N.S. 82 P2 Syn-2 compared with the N.S. 82 Syn-2 original population. Simple correlation coefficients between self- and cross-fertility levels with­ in populations were either nonsignificant, or if significant, were too low to be considered biologically important. !I published as Abstract No. 80-1401, Abstract Series, Nebraska Agricultural Experiment Station.

60 Enzyme Electrophoresis as an Aid for Alfalfa Breeding Carlos F. Quiros Department of Genetics, University of Alberta, Edmonton, Alberta Electrophoresis is a biochemical technique that discloses plant traits con­ trolled by sj.ngle genes. This makes possible the assessment of the genetic make-up of plants. The technique we have employed consists of running indivi­ dual plant extracts (roots, leaves,or ovules) in starch gels at 300v for about 4 h (1). In this way, the enzymes present in the extract are separated in the gel according to their electrostatic charge, forming a specific pattern of bands (zymograms) that can be visualized by staining for specific enzyme acti­ vities. The technique is sufficiently sensitive to distinguish between functionally similar enzyme variants produced by mutation of a gene and this allelic variation can be shown to behave in a Mendelian fashion in diploids. Tetraploid plants with different degrees of heterozygosity for a given gene, upon selfing, segregate in a tetrasomic fashion. Enzyme electrophoresis is particularly powerful, because of its ability to detect heterozygotes. I have found several genetic markers that can be used in diploids and tetraploids for genetic and breeding studies of alfalfa: 1) Identification of mother plants of breeding lines preserved in nursery plots. The plants are characterized by unique zymograms, di,stinguishing them from "volunteers" which replace dead or weak plants (1). 2) Detection of natural cross-pollination and hybridization. Monoallelic, homozygous plants differing in two alleles of a given locus are interplanted. The resulting hybrids, if crossing has occurred, will be hetero­ zygous and diallelic, and can be detected by the simultaneous expression of parental alleles. This determination can be done in the developing ovules, if the genes controlling the enzyme leucine-aminopeptidase (Lap) are used. For controlled hybridization studies or crossings, a coil from the pods of the pistillated parents can be cut about 20 days after fertilization. The ovules from the coil are extracted and assayed for Lap to determine if they have originated by crossing or accidental selfing. The rest of the ovules in the cut pod are left in the plant to complete their development. This is specially useful for annual Medicago species, which are autogamous and difficult to emasculate. 3) Determination of genetic variability of accessions in a germ­ plasm collection. This information is useful in the management and utiliza­ tion of genetic resources, especially to maintain the variability present in the original accessions. 4) Detection of possible centers of diversity of Medicago species closely related to alfalfa. This would allow selection of the most rewarding accessions for alfalfa breeding (2), 5) Testing the hypothesis of maximum heterozygosity (3). This might be possible because of the availa­ bility of multiple alleles for the genes studied. 6) Construction of linkage groups. Observation of tight linkage between useful genes, such as those controlling disease resistance and electrophoretic markers, should allow desirable plants to be selected on the basis of the markers, without the need for inoculation (4). References 1. Quiros, C. F. 1980. Crop Science 20: 262-264, 2. Quiros, C, F. 1979, Forage Notes 24: 18-24. 3. Dunbier, M. W. and E, t. Bingham. 1975, Crop Sci, 15: 527-531. 4. Rick, C. M, and J. Fobes. 1974. Rep. Tomato Genet. Coop. No, 24: 25.

61 Variation in Morphological Characteristics Among Plants of Alfalfa Cultivar Saranac AR F. W. Snyder, G. E. Carlson, J. H. Elgin, Jr., and N. J. Chatterton Light and Plant Growth Laboratory, PPHI AR, SEA, U.S. Department of Agriculture Beltsville, Md. Mean growing capital and relative growth rate are important components of dry matter accumulation in plants. The amount of leaf area, because it is often directly related to light interception, is a major component of growing capital. In alfalfa, the growth rate and the frequency of cutting cycles markedly influence the mean growing capital; frequent harvest reduces the mean growing capital. Genetically controlled differences in the maturity, the accretion of growing capital, and relative growth rate exist in alfalfa. There is a need to quantify the characteristics that may contribute to a greater yield of high quality herbage. We have conducted two greenhouse experiments, Experiment 1 in summer (16 plants) and Experiment 2 in winter (96 plants), on Saranac AR using a 15-hour photoperiod (supplemental incandescent light) in both experiments. We determined the variation among plants for a number of characteristics and identified the high-yielding individuals in three cycles of blooming. The data are summ~~ized in Tables 1, 2, and 3. Summary: 1) Herbage per plant summed over three cycles of blooming varied up to 18-fold (Table 1). 2) Dry weight accumulated per plant per day in the three cycles of blooming varied among plants by more than 12-fold (Table 1). 3) Accumulated days to complete three cycles of blooming varied less than two-fold among plants (Table 1). 4) Plants that bloomed only three times in 150 days yielded 11% more than plants that bloomed four times during the same time period (Table 2). 5) Regression data (Expt. 2) indicate that somewhat longer intervals between harvests would be one way to increase the" yield of herbage. 6) Leaves contributed 77~ of the weight of the side axillary branches, whereas leaves contributed about 48~ of the weight of the whole shoot (Table 3). 7) Leaf/stem ratios among individual plants varied up to 25% from the mean for all stems and up to 25% from the mean for side axillary branches (Table 3). 8) The axillary branches comprised from 6 to 26% of the shoot weight for three cuttings, with a range of 3 to 41% within a single cutting. The range in percent of shoot weight contributed by axillary branches for the 20 highest yielding plants ranged from 10 to 33%. 9) Our data suggest that individual plants of Saranac AR have a genetic component that facilitates the production of axillary branches which is sufficiently stable to permit selection and study of the effect of this trait on herbage yield.

62 TABLE 1.--Range in time to complete three cycles of blooming and in yield among alfalfa plants of Saranac AR cultivar grown in the greenhouse Expt. No. days for Herbage produced, grams dry wt. Dry wt. per day 3 cycles of Range Mean bloom

1-S 67 - 121 2-W 113 - 196 1.9 - 34.5 9.7 0.017 - 0.210

TABLE 2.--Herbage yield in relation to number of cycles of blooming of alfalfa cultivar Saranac AR grown in greenhouse in winter

Days of No. of cycles Her-bage yield growth of blooming g as f,

156 3 10.8 100 158 4 9.6 89

TABLE 3.--Range in leaf/stem ratios among alfalfa plants of cultivar Saranac AR grown in greenhouse in winter

Percentage of leaf weight Range Mean

All stems 39 - 60 48 (Means for 3 cuttings)

Side axillary branches 58 - 88 77 (Means for 2 cuttings)

63 Harvest and N Fertilizer Effects on Alfalfa Root Nodule Enzymes of Ammonia Assimilation R.G. Groat and C.P. Vance USDA-SEA-AR and Department of Agronomy and Plant Genetics University of Minnesota st. Paul, Minn. A major portion of total plant N in alfalfa can be derived from symbiotic N2 fixation. Large amounts of ammonia are generated in bacteroids as the initial product of N2 fixation. Most of this ammonia (90-95%) is exported from bacteroids into the surrounding nodule cell cytoplasm and assimilated into organic compounds (1). These organic compounds are then transported from the nodules to the shoots. The assimilation of ammonia into organic compounds is thought to involve the following plant nodule enzymes (2); glutamate dehydrogenase (GDH), glutamine synthetase (GS), and glutamate synthase (GOGAT). The relative contribution of these enzymes of ammonia assimilation in alfalfa is not fully established (2). Recent work in this laboratory has shown that forage harvest and N fertiliza­ tion cause a rapid decrease in symbiotic N2 fixation of alfalfa, accompanied by temporary, localized senescence of nodule tissue (3,4). The objectives of this experiment were to assess which plant ammonia assimilating enzymes are most associated with N2 fixation and to evaluate the effects of harvest and applied N on N2 fixation and ammonia assimilating enzymes in alfalfa root nodules. Act1vities of nodule ammonia assimilating enzymes, acetylene reduction activity (AR), and other physiological parameters were measured at 0, 1, 4, 10, and 15 days after harvesting (80% shoot removal) and/or appli­ cation of N fertilizer at 40 or 80 kg NO;-N/ha. Alfalfa acetylene reduction activity decreased 50-70% within 24h after har­ vesting and/or N application. In each case, declining N2 fixing capacity was followed by a decrease in nodule soluble protein of more than 50%. These observations are consistent with previous studies,indicating that harvesting or N application can induce alfalfa nodule senescence (3,4). AR or harvested alfalfa not treated with NO; began to recover by day 15 as shoot reg£owth became significant, whereas that of all plants treated with 80 kg N03-N/ha and harvested plants treated with 40 kg N/ha remained low (less than 5% of control) for the duration of the experiment. AR of unharvested alfalfa treated with 40 kg N/ha declined to an intermediate level and may have begun to recover slightly by day 15. Initial shoot regrowth of harvested alfalfa was not affected by applied NO- at 40 or 80 kg N/ha. Gradual depletion of root nonstructural carbohydrate re~erves, observed following harvest, was independent of applied N fertilizer. Initial in vitro activities of alfalfa nodule ammonia assimilating enzymes (at peaklN fixation) were GS=870 ~ 20, GOGA:=11?0 ~ 60, NAD+-GDH (o~idative deaminatio~)=610 + 20, NADH-GDH (reductive am1nat10n)=640 ~ 50 nmol/m1n/g fresh wt. nodules: Corresponding specific activities were GS=78 ~ 5, GOGAT= 97 + 2, NAD+-GDH=54 ~ 1, NADH-GDH=58 ~ 6 nmol/min/mg protein. The o~s:rved levels of activity of all the above alfalfa nodule enzymes were suff1c1ent

64 to account for theoretical rates of ammonia production via symbiotic N2 fixation (AR=240 ± 30 nmol/min/g fresh wt. nodules) Specific activities of alfalfa nodule GS, GOGAT, and NAD+-GDH decreased in response to harvesting and/or applied N parallel with, but less rapidly than, AR after an initial lag of 24h. Specific activities of each of these nodule enzymes from harv:sted alfalfa not treated with NO~ recovered to levels equal to those of unharvested controls as AR began to re~over by day 15. Recovery of enzyme specific activities was also observed for unharvested alfalfa treat­ ed with 40 kg NO--N/ha. The data indicate high functional levels of alfalfa nodule GS, GOGAT~ and NAD+-GDH are associated with high rates of symbiotic N2 fixation. Nodule NADH-GDH specific activity remained constant or increased slightly during the period of rapidly declining AR, indicating high levels of this nodule enzyme are not tightly coupled to N2 fixation in alfalfa. The data suggest this enzyme is associated with ammonia assimilation during induced nodule senescence. Nodule NADH-GOGAT activity was very unstable in commonly used extraction buffers (e.g. Tris, phosphate) of pH greater than 7.0, suggesting previous reports (5,6) of the absence of this plant enzyme in alfalfa nodules reflect extraction and assay procedures. A Mes pH 6.8 extraction solution, including 2% (v:v) 2-mercaptoethanol and 15% (v:v) ethylene glycol, minimized loss of NADH-GOGAT activity in nodule extracts (to 1-2%/h) without affecting GDH or GS activities. The results of this experiment indicate that the host plant GS/GOGAT enzyme system functions to assimilate symbiotically fixed N in alfalfa nodules. The observed changes in specific activities of ammonia assimilating enzymes relative to one another reflect a major shift in alfalfa nodule N metabolism during senescence induced by harvesting and/or applied NO;. Levels of nodule GS, GOGAT, and GDH may be useful indicators of host plant metabolism associ­ ated with symbiotic N2 fixation in alfalfa.

References

1 • O'Gara, F. and K.T. Shanmugan. 1976. Regulation of nitrogen fixation by rhizobia: export of fixed N2 as NH +. Biochem. Biophys. Acta 437:313- 321. 4 2. Boland, .M.J:. A.M. Fordyce, and R.M. Greenwood. 1978. Enzymes of nitrogen metabol~sm ~n legume nodules: A comparative approach. Aust. J. Plant Physiol. 5:553-559. Vance, C.P., G.H. Heichel, D.K. Barnes, J.W. Bryan, and L.E. Johnson. 1979. Nitrogen :ixation,.nodule .development, and vegetative regrowth of alfalfa (Med~cago sat~va L.) following harvest. Plant Physiol. 64:1-8. 4. Vance, C.P. 1979. Nitrogen metabolism in alfalfa. Proc. 16th CAIC, p. 3. 5. Duke~ ~.H.~ M. COl~ins, and R.M. Soberalske. 1980. Effects of potassium fer~~l~~at~on on n~trogen fixation and nodule enzymes of nitrogen meta­ bol~sm ~n alfalfa. Crop Sci. 20:213-219. 6. Brown, C.M. and M.J. Dilworth. 1975. Ammonia assimilation by Rhizobium cultures and bacteroids. J. Gen. MicrobiOl. 86:39-48.

65 Description and Inheritance of Root Traits in Alfalfa M.A. Brick and O.K. Barnes Department of Agronomy and Plant Genetics University of Minnesota St. Paul, Minn. limited information is available concerning the amount of genetic variability and mode of inheritance for alfalfa (Medicago sativa l.) root traits. Studies were conducted to provide information about the genetic control and variability for several root characteristics. An alfalfa plant with orange root tissue was observed while evaluating root disease resistance. Genetic studies re­ I vealed that the orange root color was controlled by a single recessive gene , (or) with tetrasomic inheritance. The orange root phenotype was expressed only in the nulliplex condition. Results of the chemical analysis indicated that the pigment which conditioned the orange root color was poly-cis-lycopene. Alfalfa plants with lobes along the surface of the root vascular cambium (as viewed in cross-section) were observed while evaluating root disease resis­ tance. Genetic studies determined that the lobed-cambium trait was controlled by a single duplex-dominant gene (lc) with tetrasomic inheritance. The lobed appearance resulted from unequal production of xylem and phloelm tissue along short arcs of the cambium layer. Essentially nothing is known about the genetic mechanisms controlling root bark area (as viewed in cross-section) despite the importance of the root bark for organic food storage and other physiological processes that occur in the root. Qualitative genetic analyses were conducted using a tetrasomically inherited duplicate gene model (RB1 and RB?) without dominance. The observed segregates among S ,F and F families generally fi~ the .propos~d genetic . model. Histologic!l studies ~ndicated that plants w1th contrast1ng proport1ons of root bark area could be distinguished shortly after secondary growth was initiated. The two plants used in the anatomical studies contained appr~xi­ mately 33% and 83% root bark 63 cm from the root tip. It should be pos~lble to develop alfalfa populations with contrasting root bark area for use 1n physiological and plant breeding studies.

66 Insights After One Year of Fall Dormancy Determination at Several Locations

L. R. Teuber, B. J. Hartman, and W. L. Green University of California, Davis, USDA, SEA, University of Nevada, Reno and University of California, Davis

In 1978 Barnes et al. suggested the fall dormancy of a cultivar could be a very valuable descriptive tool in alfalfa. However, it would be necessary to establish the relationship between fall dormancy in Minnesota and other locations.

Based on fall dormancy determinations on two dates at Davis, Calif., in the fall of 1978, we selected 17 cultivars to establish in dormancy trials at 13 locations in the western United States plus Minnesota and New York. Included in the 17 cultivars were the 6 check cultivars used in Minnesota {'Norseman', 'Vernal', 'Ranger', 'Saranac', 'DuPuits', and 'African'}. Eleven other cultivars were placed in the trials based on their fall dormancy class and response (or lack of response) on the two dates at Davis. Loca­ tions were selected on a north-south and east-west grid. North-south loca­ tions were selected to have similar temperatures. East-west locations were selected to have similar light durations.

The correlation between Minnesota and other locations ranged from 0.42 to 0.97 (df = 66). Significant genotype x location and genotype x location x date interactions were found. Although changes in rank of the cultivars occurred among locations most of the interactions were due to differences in degree of response. All locations seem to be equal in ranking cultivars that are very different in fall dormancy. However, it may be necessary to determine fall dormancy in several locations in order to rank cultivars that are similar in fall dormancy.

References

1. Barnes, D. K., D. M. Smith, R. E. Stucker, and L. J. Elling. 1978. Fall dormancy in alfalfa: a valuable predictive tool. Proceeding Twenty-Sixth Alfalfa Improvement Conference. p. 34. 2. Smith, Dale. 1961. Association of fall growth habit and winter survival in alfalfa. Can. J. Plant Sci. 41:244-251.

* The authors wish to thank the followl."ng sCl."entl."sts f or their help in the dormancy trials. They will be co-authors when the data are published. D. K. Barnes, B. Burrows, R. H. Grl."PP, O. J. Hun, t I • I . Kawaguchi, D. L. Lancaster, B. A. Melton, R. N. Peaden, M. H. Schonhorst, and D. R. Viands.

67 A Pink Pea Aphid Biotype on Alfalfa John L. Kugler W-L Research Inc. Highland, Md.

During the fall of 1979, a pink colored form of pea aphid (Acyrthosiphon pisum (Harris» invaded alfalfa growing in the greenhouse at our facilities in Highland, Md. The pink aphid population maintained itself in small numbers in cultures of the common green form throughout the winter months. To my knowledge, the pink biotype has to date not been reported attacking alfalfa in the U.S., however, a red biotype was reported to occur on alfalfa in Europe (1).

In May 1980, an experiment was designed to determine resistance levels of selected released alfalfa cultivars and advanced synthetics and to study the impact of the pink aphid on our screening tests. ,

Pink aphids were cultured on pea aphid-susceptible alfalfa in a screened cage for population increase. Fifteen cultivars and four experimental synthetics were chosen for evaluation. 'Arc', 'CUF 101', 'BAA-15', and 'PA-1' were in­ cluded as resistant checks and Vernal as the susceptible check. Five replicates of each entry were planted in 5-inch fiber Bots in a peat-based media and grown under a greenhouse environment of 130 to 33 C. Nine-day old seedlings were thinned to 20 plants per pot and infested with pink aphids at about 30 aphids per pot. Aphids were not confined and were observed to move from pot to pot. Ratings of tolerance to aphid feeding were made on the 17th day. Each plant was given a score on a scale of 1 to 5, with 1 = most tolerant. Susceptible plants were severely stunted. Interveinal chlorosis was noted in newly emerged leaves on many severely stunted plants. No apparent difference in aphid number was detected on plants within or between entries. Cultivar reaction to the pink aphid was generally consistent with what would be expected with the common green form of pea aphid. Mean scores ranged from 1.9 for BAA-15 to 4.7 for Vernal. Some cultivars, however, suffered much more damage than expected, e.g., Arc, Saranac AR, WL 312, and WL 318 with mean scores of 4.3, 4.6, 4.4, and 4.4 respectively. This suggests that the pink biotype, if it becomes established, could become an economically important pest on pre- viously resistant alfalfas. The occurrence of tolerant segregates indicates that selection for germplasm improvement is possible. It is also apparent that in future pea aphid resist­ ance trials, it will be necessary to separate the pink biotype from the green to ensure unconfounded ratings and plant selections. References Hubert-Dahl, M. L. 1975. Anderung des Wirlswahlverhaltons dreier biotypen 1. Von Acyrthosiphon pisum (Harris) nach anzueht auf versehiedenen virtspflanzen. Beitr. Entomol. 25:77-83.

68 Fall Growth of Alfalfa Used in Wisconsin To Identify Strains Sinc.e 1918 Dale Smith Emeritus Professor, University of Wisconsin Common & Grimm were the main cultivars in the early period of alfalfa culture in Wisconsin, & Grimm was much superior to Common. The high-price of winter-hardy Grimm seed caused considerable irregularity within the seed industry of the northern states pre- & post-1920. Little of this occurred in Wisconsin where L.F. Graber helped seedsmen locate seed supplies of genuine Grimm with a simple field growth test (Wisconsin Bull. 502, 1953). In 1918, Graber found that with cutting in early September, Common alfalfa· regrew tall and erect while Grimm had a short and spreading growth. Tall-growing plants were the ones that winterkilled. Differences were pronounced, and by this means, Graber located growers of genuine Grimm for the Wisconsin seed trade & farmers (Wisconsin Bull. 502, 1953, p. 100, & "Mister Alfalfa", Gra-Mar, Madison, Wis., 1976, p. 283-284).

Autumn-growth was used later by Graber & Dal~ Smith to show in side-by­ side pot teSS seeded in 1945 & in 1947 that certified Ranger alfalfa produced in the southwest (Ariz., S. Calif.) grew taller during autumn of the seeding year following cutting in early September than certified Ranger produced in the north (Mont.). These differences were verified in a comprehensive field­ plot test of Ranger seed sources established by Dale Smith & Graber in 1949 (Wisconsin Res. Bull. 171, 1950). These were the first observations that changes could occur during seed increase of a winter-hardy alfalfa outside of its northern area of adaptation. Autumn-growth tests at Wisconsin until 1952 were made in broadcast­ seeded plots where populations masked the variability among individual plants. Thus, a method was initiated in 1952 with spaced-plant rows. Seed was broadcast in mid-May in rows 18 to 24 inches apart. Plants were thinned 4 to 6 weeks later to single plants every 12 to 14 inches in the row. Tran~planting & machine-cultivating was never practiced so plant crowns would develop normally & not be covered with soil, an important precaution when winter survival readings will be made. Topgrowth was removed in mid­ July & uniformly about September 10 (at Madison, tvisc.). In mid-October, each plant was measured for height with a ruler & classified into short, medium, tall, & extra tall height groupings. At times, ratings also were made on whether the autumn growth was spreading, intermediately-spreading, or erect. After measuring, the autumn growth was removed to reduce winter snow cove:. Winter survival was recorded the next spring. Plants lacking cold hard~ness grow tall & erect during autumn, while hardy plants grow short & prostrate. Research with this technique was begun in 1953 to further evaluate seed increases of Ranger alfalfa (Agron. J. 47: 201, 1955). Details of the ~ethod were published in Nat. Alfalfa Improv. Conf. Rpt., p. 19-21, 1956, & ~n Can. J. Plant Sci. 4: 244, 1961. Similar space-plant tests of various alfalfa. strains were established annually from 1953 to 1965 (data mimeograph­ ed), & ~ncluded a study of seed increases of Vernal & Narragansett (Agron. J. 50, 226, 1958). The method has been used by commercial alfalfa plant breeders to sele~t cold-hardy ~lants & by the USDA Foundation Seed Project to check conform~ty of foundat~on & certified seed increases. ---A Historical Sililoquy

69 Combining Ability in Alfalfa Combinations Made with Male Sterility B. Nagy GATE-Agricultural Research Institute Kompolt, Hungary The yield of a hybrid depends on the combining ability of its parents. In 1973-]975 we examined the combining ability of a cytoplasmic-genetic male sterile clone, 3 genetic sterile clones, 1 self-incompatible clone and 1 mutant "exposed-stigmal! clone, which were crossed by 6 untested male parents. In 1974-76 we crossed cms-F with 14 strains or varieties for the production of 3 way-crosses. With the l help of a progeny-test we determined the propor­ tion of specific and general combining ability. On the hasis of a SC- and TC-progeny test the following conclusions were made: a) That additive genetic variance gave the greater proportion of genetic variance. In both tests the female general combining ability was most important. b) The nonadditive genetic variance was significant only in the first year. Its effects markedly decreased during the three cuttings. c) The general combining ability of the genic steri1es was significantly better than the cms-clone. d) A cutting schedule specially adapted to the rhythm of development was very important in the determination of relative yield. References

1 . Nagy, B. 1977. Himsteril 1ucernaklonok kombinalodokepessegi vizsga1ata faktoria1is parositasi mode11ben I. Novenytermeles, 2-3: 105-113. 2. Nagy, B. 1979. Himsteri1 1ucernaklonok kombinalo~o~epesseg;- ... vizsga1ata faktorialis parositasi mode11ben II. Novenytermeles, 2: 107-113.

Evaluation of Pasture Alfalfa Hybrids in Grazing and GrazinQ Simulation Juri M. Piskovatski and Galina V. Stepanova All-Union Williams Fodder Research Institute, Lugovaya, Moscow region, USSR. This study is being ca-rried out in the All-Union.\~~ll;ams Fodder Research Institute, Moscow region,under the condltl0ns of Non- chernozemic Zone.

70 The combination of longevity and persistence under grazing and highly competitive grass mixture is difficult to achieve when breeding new pasture varieties of alfalfa. At the All-Union Williams Research Institute this problem is being solved by using different methods of breeding. Attention is focused on the us: of hybridization involving donors carrying all necessary characters. Slng1e crosses are made between donor parents and the most adapted and productive local bred varieties. Evaluation of initial material, obtained hybrids and complex hybrid populations are carried out in the grass mixture under the irrigated pasture management of 4-5 cycles of grazing annua~ly and at the same time with grazing simulation (3-4 cuts at the sward helght 35-40 sm). The aim of the study is to evaluate produced hybrids directly under the pasture conditions and to determine the possibility of evaluation of breeding material of the pasture type by a grazing simulation regime. Bastard alfalfa (Medicago varia) was the most suitable variety for the pasture use under the less favorable conditions of the zone. Hybrids F P 29-392 (Servernaya hybridnaya x Gamma), P 67-26 (Omega x Moskovska~a hybridnaya), P 37-30 (Mesopotamskaya x Moskovskaya hybridnaya) featured high rate of growth in grazing and grazing simulation regimes. In grazing,their daily growth amounted to 1.3-3.1 sm, in cuttings, 1.1-2.3 sm. By reasons of higher rates of growth hybrids sown on the pasture reached pasture maturity (sward height 35-40 sm) by the first grazing 5-8 days earlier and by the third grazing 15-26 days earlier than in grazing simula­ tion. Alfalfa content in the grass mixture defines the competitive ability and response of hybrids studied to the frequent cuttings. Hybrids P 88-1 (Rhisoma x Tashkentskaya I x AZNIKhI x Khorezmskaya x local from Romania), P 67-26, P 29-392 and P 98-2 (complex hybrous population developed when pollinating the best biotypes collected from 4 single hybrids) are characterized by sufficient persistence to trampling and high competi­ tive ability. In the 1st year of uti1ization,93.5-96.5% plants of these hybrids formed the yield (standard - 97.3%). In the 3rd year, the percent stand was 56.1-64.7% plants for the hybrids and 39.6% for the standard. Productivity of the best hybrids amounted to 129.7-146.4% to the standard level: .Pro~isin~ hybrids mairytained their high productivity during 3-4 years of ut1l1zatlon wlth both graz1ng as well as grazing simulation. In the grazing simulation regime, the legume component in sward was found to be sharply decreas:d in the 2nd year of utilization; on the irrigated pasture a marked reductlon of alfalfa stand was noticed in the 3-4 year. Deep setcrow~s and high 1~ve1s of particu1ation provided for higher persist­ ence.of hybr1ds to tramp11ng and unfavorable conditions. Depth of crown in h~brlds P 67-26, P 80-149 ~as 2.6:2.7 ~m by the 3rd year in pasture uti1iza­ t10n.tests.and 2.3-2.8 sm 1n graz1ng slmulation tests. In grazing tests partlcu1~tlon effectswere?bserved in 95%.of alfalfa plants, and in 60% of the ~ut~lrygS. Iry both reglmes of evaluatlon 1eafiness of the plants showed no slgnlflc~nt dlfferences and amounted to 53.6-73%. Digestibility of the green materlal was at the standard level and varied from 76.6-78.9%.

71 We concluded that different regimes of evaluation did not significantly influ~nce economic and ~a1~abl~ features of hybrids. At an early stage of breed1ng of pasture var1et1es 1t would be possible to use grazing simulation instead of the more complex regime of the sward utilization.

R. Steuckardt I VEG Saatzucht Gotha-Friedrichswerth \ 58 Gotha VIII GDR l Saatzucht, Zuchtleitung

Mo~e in~ensive forms.of alfalfa:cu1tivation in the last 20 years in GDR re­ qU1red 1ncreased res1stance aga1nst fungus wilts, especially against Vertici11ium a1bo-atrum. The selection of resistant olants after artificial inf~ction w~s initiated ~n 1965. ~henot~pic recurrent selection in European bas1c mater1a1 resulted 1n the reg1strat10n of the first resistant GDR­ variety 'Vertibenda' (10 basic-clones) in 1973. In 1978, another resistant and high yielding synthetic variety 'Verco' was registered in the State variety-list. During the selection and testing of resistant and non-resistant synthetics it was shown that under conditions without infection the best of both groups had the same level of yield. Under conditions of high infection pressure - naturally and provocated - in the second year of cutting the best resistant synthetics outyielded the best non-resistant synthetics by 20-25%. This trend was shown in the State trials at 8 to 10 locations allover the alfalfa growing districts (Table 1). In the mean of eight different seeding years from 1970 to 1977, the resistant varieties Vertibenda (GDR), Verco {GDR),and Swedish resistant varieties out­ yielded by 14% all non-resistant varieties and strains in the second year of cutting. At locations with extremely high infection rates, the resistant varieties out yielded in the second cutting year (3rd year of growing) the non-resistant ones by 20%. From these results, we concluded, that the new Vertici1lium-resistant varie­ ties from GDR and Sweden produced higher yields in the 2nd and 3rd year of cropping and were comparable with older European varieties before wilt be- came a problem. We demonstrated in separate investigations that quality factors were positively influenced by resistance (Table 2). An increasing prop?rtion wilted p~ant~ (scale 3-5) decreased quality, especially the raw prote1~ c?ntent and ~n v1tro digestibility of dry matter. Raw fibre pe~c~nt~ge a~d 11gn1n content 1n­ creased with increased proportions of Vert1c1111um-w1lted fodder. The content

72 of saponin was not influenced by Verticillium. Our results showed that optimal fodder quality was obtained when resistant varieties were grown. Table l.--Drymatter yield of varieties with different level of resistance against Vertici1lium albo-atrum from locations with high and with medium (normal) Vertici11ium-infection rate (tons per ha drymatter, 1970-1979, n = 8 locations) Locations with Locations with extremely high medium Verticil1ium­ Vertici11ium­ infection rate infection rate Varieties 2nd year 3rd year 2nd year 3rd year Resistant varieties: Vertibenda GDR Verco GDR 13,6 10,1 13,4 13,3 Vertus Sweden Sverre Sweden NS -20% NS -14% Non-resistant varieties: Bende1ebeur GDR Europe France Wa rotte France 13,3 8,4 13,2 11,7 DuPuits France Maga1i Gr.Br.

Table 2.--Qua1ity factors of plants after infection with Verticillium albo- atrum spores, X 1976-1978, arranged in scale degrees of resistance 0-5 Scale In vi tro degrees of Dry- Crude digest- Raw resistance+ matter ~rotein abi1itx fibre Cellulose Lignin SaEonin % g/kg :: 0 1 22.4 21.7 68.4 21.8 26.4 6.7 4.2 2 24.9 18.6 69.0 26.7 28.9 8.0 4. 1 3 28.5 18.4 64.6 29.7 27.4 9. 1 3.7 4 42.0 16.7 62.4 29.6 27.6 11.2 4.3 5 72.0 13.3 51 .7 34.5 31.0 14.8 4.6 + o = without symptoms of wilting, 5 = wilted and fully susceptible.

73 New Data on The Amount of 5elfing in Alfalfa Franco Lorenzetti, Adelmo Panella,and Fabio Veronesi Plant Breeding Department of University of Perugia, Perugia (Italy) Estimates of the percent se1fing in alfalfa that are presented in the literature (1,2) were obtained by the usual method of controlling open pol­ lination progenies of plants homozygous for recessive markers. They indi­ cated that an average of 15% of alfalfa seed resulted from selfinQ. Due to the autotetrap10id pattern of inheritance of alfalfa (3,4) it is unlikely that plants homozygous for recessive markers have been originated by inter­ crossing of heterozygotes rather than by self-fertilization. On the other hand, self-fertilization brings about a reduction in self-fertility (5,6), so that the amount of selfing estimated by this way should be underestimated. A more correct approach could be the study of the distribution curves of quantitative traits of populations obtained by controlled selfing and cross­ ing compared with the curves of natural populations. In alfalfa, it is not difficult to obtain artificial populations by controlled selfing (5,) and crossing (F ) of a randomly chosen sample of plants of a natural population. Assuming a ~orma1 distribution of F, and 51 and assuming also that the natural population (Po) is a mixture of S1 and F , for quantitative traits the follow­ ing system of equations can be wr1tten: l KF + KS = 1 1 1 { KF x MF + KS x MS = 0 1 111 where MF = X - Xp and MS = Xs - Xp. In the system, K5 and KF indicate 1 F 1 0 1 1 0 1 1 the amount of selfing and crossing, respectively. At Perugia (Italy),an experiment has been carried out (1976-79) utilizing three lots of seed obtained from a local population of alfalfa by a) controlled self-pollination (S]); b) controlled cross-pollination (F,); c) open-pollination (PO). The three lots of seed were from randomly chosen plants of a stand 3 years Old. The experiment was based on the hypothesis that in a 3-year old stand, only vigorous pl.ants derived from crossing should be obtained (7,8). Six hundred plants for each o! ~he ~hree p~pula­ tions have been studied for the two characters that maXlmlze lnbreedlng. effects: height and green matter yield._ As.expecte~, the three ~opulatlQns resulted significantly different, being Xp lntermedlate between Xs and XF . o 1 1 Solving the above system for the actual data of the height, the following. figures were obtained: KF = 0.64 and KS = 0.36; for the green matter Yleld, 1 1 figures of the same order were also obtained (K = 0.66; KS = 0.34). F1 1 It may be concluded that, in the conditions of Central Italy, the amount of selfing in alfalfa is of the order of 35%. The data give support of the

74 conclusions of previous authors (1,9) and indicate that the problem of the amount of fertilization of alfalfa should be reconsidered. References 1. Lesins, K. 1961. Mode of fertilization in relation to breeding methods in alfalfa. Z. Pflanzenzuchtung 45: 31-54. 2. Mayer, 1972. L'amelioration des plantes en France. Ann. Am~l. des Plantes, Num~ro Hors Serie, 63. 3. Demarly, V. 1963. Genetique des tetraploides et am~lioration des p1antes. Ann. Am~l des Plantes 13: 307-400. 4. Stanford, E. H. 1951. Tetrasomic inheritance in alfalfa. Agron. J. 43: 222-225. 5. Brink, R. A., and D. C. Cooper. 1963. The mechanism of pollination in alfalfa (Medicago sativa). Amer. J. Bot. 23: 678-683. 6. Tysdal, H. M., Kiesse1bach, T. A., and Westover, H. L. 1942. Alfalfa breeding. Nebr. Agr. Expt. Sta. Res. Bu1. 124. 7. Kehr, W. R. 1976. Cross-fertilization in seed production in relation to forage yield in alfalfa. Crop Sci. 16: 81-86. 8. Lorenzetti, F. 1978. Autoimpo11inazione e impol1inazione incrociata in erba medica. Sementi E1ette XXIV (4): 33-37. 9. Hanson, C. H., Graumann, H. 0., Elling, L. J., Dudley, J. W., Carnahan, H. L., Kehr, W. R., Davis, R. L., Frosheiser, F. I., and Hovin, A. W. 1964. Performance of two clone crosses in alfalfa and an unanticipated self pollination problem. Agr. Res. Servo U.S.D.A. Tech. Bull. 1300.

75 The Analysis of the Growth Curve of Alfalfa (Medicago sativa L.) Manuel V. Benezra R. and Tamara Oropeza Universidad "Sim6n Rodrfguez". Vicerrectorado de Ciencia, Tecnolog1a y Producci6n Agroindustrial. Aptdo. 66802. Las Am~ricas 1061. Caracas - Venezuela. In the determination of the growth pattern of the different varieties of alfalfa in the Experimental Station "Cataurito", a growth curve was analysed. The Methodology of Brody was used as the Model of Analysis. Twenty plants from each alfalfa plot were studied,and growth heights were measured weekly for each plant selected. The growth curves were analyzed for the following varieties: Synthetic Bajo Seco, Sa1adina, Pob1aci6n B, Maracay, Peruana Pe1uda, Pob1aci6n C Maracay, Synthetic Maracay, Ita1iana, and San Martin. Using this method 4 physiological ages were measured from the time of seeding until the first cutting. Between subsequent cuttings 3 physiological ages appeared. Before the first cutting the 4 physiological ages were of the fol­ lowing durations: from zero to 2 weeks, from the 2nd to the 3rd weeks, from the 3rd to the 6th weeks, and from the 6th to the 8th weeks. During re­ growth after the first cutting the physiological ages included from the first to second week, from the 2nd to the 3rd week,and from the 3rd to the 5th week. y - y All of the calculated values were tested by Minot's equation R = 2 Vi 1 K = In (R+l), and were found to the same obtained by Brody's method. Ln Y2 - Y1 Brody's Method: K = T - T 2 1 The different physiological ages permit determination of the best cutting time and explain the differences between florescence and fruiting,that is, when widespread florescence occurs with fruiting or when florescence occurs not followed by fruiting. For the regrowth of each variety by cutting and physiological ages, the values obtained were: . -From the data presented here it can be said that: It is posslble to determine physiological ages in alfalfa. .. -Each physiological age has a K-value characterlstlc of each age and variety. ..t -It is possible to determine the best cutting tlme for ea~h varle y. -The data explain the difference in gro~t~ pattern accordlng to flower- ing and fruiting or the absence ~f frultlng. . -The measurement of height well wlth those.of wel~ht.and.volume. -The data indicate a possibility of selectlng varletles ln accordance with the growth velocity in each physiological ages. It should be possible therefore to produce new.varieties, ~ncor~orating the characteristic of maximum growth ln each phYSlologlcal age

76 Table l.--K-values for periods of growth from seeding to flowering K-values/week Variety 0-2 2-3 3-6 6-8 Syn. Bajo Seeo 0.588 0.788 0.359 0.000 Saladina .406 1.099 .493 .143 Poblaci6n B .560 1.098 .442 .087 Pob1aci6n C .811 1.329 .277 .124 Syn. Maracay .540 .981 .483 . 112 Peruana Pe1uda .406 1.299 .409 .108 Ita1iana .406 1.299 .228 .041 San Martin .789 .694 .304 . 150

Table 2.--Number of days necessary to duplicate height for each variety at each of four physiological ages Number of days to achieve same height/week Variety 0-2 2-3 3-6 6-8 Syn Bajo Seco 8.25 6.08 13.58 indefinite Sa1adina 12.16 4.41 9.8 34.65 Pob1aci6n B 8.66 4.41 11.17 57.65 Poblaci6n C 5.97 3.66 17.77 40.76 Syn. ~1aracay 9.00 4.95 10.04 43.3 Peruana Pe1uda 12. 16 3.70 11.95 46.20 Italiana 12. 16 3.73 21.00 115.5 San Martin 6.13 6.99 16.12 32.14

77 Table 3.--K-values for alfalfa varieties measured over four regrowth periods K-va1ue/week of regrowth Variety 1-2 2-3 3-5 5-6 REGROWTH 1 Date: January 11 to February 15

Pob1aci6n "B" 0.237 (1-2\~)* 1.387 (2-3W) 0.213 (3-5W) Pob1aci6n "e" .419** 1.327 .213 Syn. Maracay .519 1.284 . 141 Peruanape1uda .336 1.082 .318 V. Ita1 iana .182 1.358 .123 San ~1artin .288 1.098 .315 * W: Week; ** K-va1ue. ------REGROWTH 2 Date: February 15 to March 21

Pob1aci6n "B" 0.336 (l-2\~) . 1.016 (2-3W) 0.655 (3-4W) 0.134 (4-5W) Pob1aci6n "e" .707 1.107 .174 (3-4W) .167 (5-6\~) Syn. Maracay .573 1 .241 .208 (3-5W) Peruanape1uda .550 1. 185 .201 (3-5W) V. Ita1iana .364 1.258 .247 (3-5W) San Martin .146 .967 .570 (3-4\~) .275 (4-5W) REGROWTH 3 Date: March 21 to May 3 Pob1aci6n "B" 1.227 (1-2W) 0.312 (2-4W) 0.014 (4-5W) Pob1aci6n "e" 1.253 .404 .287 Syn. Maracay 1.284 .447 .067 Peruanape1uda 1.338 .347 .238 0.083 (5-6l~) V. Ita1iana 1.006 .513 .215 .003 San Martin .681 .584 .289 .122 ------REGROWTH 4 Date: May 3 to June 21 Pob1aci6n "e" 1.166 (l-2W) 0.812 (2-3W) 0.225 (3-4W) 0.122 (4-6W) ,,' Syn. Maracay 1.280 .658 .237 .034 Peruanape1uda 1.252 .808 .084 (3-5\~) V. Ital iana 1.050 .786 .128 .006 (5-6W) San Martin 1.050 .811 . 191 .147 (4-6W)

78 Relationship Between Growth Habit and Some Factors Effecting Alfalfa Seed Yield in Hungary S. Manningerl , K. Manni~gerl, Cs. Erdelyi 2, J~ Buglos l , L. Martinovich , and A. Dobrovolszky lResearch Institute of the University of Agricultural Sciences at Godollff,H-3356 Kompolt, Hungary; 2Research Institute for Plant Protection, H-1525 Budapest Hungary; 3University of Agricultural Sciences at Godoll~o, H-2l00 Godoll1f~ Hungary.

Together with pollinators, harmful insects play an ~qually decis~v~ ~o~e in shaping seed yield. Different pests do not show dlfferent sensltlvltles t? chemicals and their invasion mostly coincides with blooming, thereby reduclng the effectiveness of chemical control. Some pests such as Contarinia and Bruchofagus simply ";'gnore" chemical treatments applicable in large scale farming in Hungary. We launched a long-term study of pest-host plant relationship with probing possibilities of selecting for insect resistance. First stage of our pro­ gress is summarized as follows. After detailed survey of 72 varieties and selections of diverse origin we have concluded that there is a close relationship between growth habit of alfalfa and rate of pest infection effecting seed yield. In 1978 we made visual assessment of growth habit of the stand using a scale of 1-5, with 5 being the most erect types, and probed the relationship between these values and seed yield, plus factors of seed yield and rate of pest infection. The highest seed yield was produced by the more erect forms (r = 0,82, p < 0,001). With the increase of erectness, number of stems per plant decreased, but at the same time an increase of flower per stem was observed (r = 0,83, P < 0,05). Seed per pod also improved with increased values of erectness (r = 0,71, p < 0,005) and so did 1000 seed weight (r = 0,82, P < 0,02). Activity of pollinators also appeared to be best in erect plants. Close positive correlation exists between infection of Contarinia medicaginis and prostrate growing habit (r = 0,83, p < 0,05). Brucho ha us roddi on the other hand showed a negative correlation with this character r = -0,94, p < 0,001). These phenomena well accord with the observations on natural history of the~e.pests. C?ntarinia pref~rs humid habitats while Bruchofagus seeks dry condltlons especlally at the tlme of egg-laying; tall, erect plants also are more suited for the flying habit of the latter pest. Tychius f~avus seems to be ~neffected by growth habit of lucerne. Proportion of wlthered seeds consldered to be caused by Lygus infection correlated positively with prostrate growth habit (r = 0,69, P < 0,05). These data alone seem to justify to regard erectness as an indirect criterion of selection for insect resistance and - consequently for better seed yield.

79 Incorporation of resistance against Bruchofagus also appeared feasible since number of individual plants were identified with no sign of infection while the rest of the stand showed consequences of heavy attack of this pest.

Saponin Content and Its Relationship to Variety, Temperature and Field Resistance to Fusarium and Vertici11ium Fungi in Alfalfa J. Buglos, I. B6csa, K. Manninger, S. Manninger GATE Agricultural Research Institute Kompo1t, Hungary Varietal differences in saponin content of alfalfa has already been demon­ strated by several workers. Since foliage contains at least twice as much saponin as this stem, leaf/stem ratio can effect the overall saponin content of alfalfa. By testing only the saponin content of the leaf fraction,it is possible to avoid the masking effect of varying leaf/stem ratio,and data more pertinent to saponin metabolism can be obtained. Eight-week-old seedlings of 10 varieties and selections were transplanted from the glass house into nursery during the spring of 1976 with a spacing of 0.6 x 0.6 m. Over a period of 3 years 200 plants of each variety were cut 12 times at an early to late stage of budding posing an intensive cutting practice under given conditions. In the year of planting 20 plants of each entry at each cut were sampled, dried, leaf stem separated then leaf only analyzed for saponin content with the hemolysis test. Marked varietal dif­ ferences existed in saponin content as expressed in percentage of plants leaves of which gave hemolytic reaction (Table 1). The highest levels of saponin content appeared in the foliage of Orca and Sverre, the lowest in Au-Px and Szarvasi-l. Parallel with advancing cuts,saponin content showed a reduction. Saponin content and mean temperatures of the 4-week-period prior to cuts showed a possible relationship (Table 2). Since many plants in the stand were lost and they had symptoms of Fusarium and Vertici1lium wilt, rate of survival can be considered as a grade of tolerance to these fungi. Regression analysis between saponin content of varieties and rate of lost plants from May 1976 to August 1978 resulted in a negligible r value (-0,13; n = 10). Thus no close relationship between field resistance and saponin could be demonstrated.

80 Table l.--Percent of plants of hemolytic reaction 1. cut 2. cut 3. cut Average of 1-3 27.7 26.8 4.10 cut 1 . Bende1ebener 85 60 45 63,33 2. Verko 80 75 55 70,00 3. Orca 90 95 60 81,67 4. Vertus 80 75 60 71,67 5. Au-Px 45 20 25 30,00 6. Vertibenda 85 70 65 73,33 7. F-15 70 70 60 66,67 8. Furez 70 68 65 67,67 9. Szarvasi-1 45 25 25 31,67 10. Sverre 85 84 80 83,00 ------73,50 64,20 54,00

Table 2.--Mean temperature of 4-week period prior to each cut

29.6-27.7 30.7-26.8 7.9-4.10

Mean temperature 22,5 17,8 15,2

Ten Years Research Work on Hybrid Alfalfa in Hungary Z. Irdjtos Agricultural Research Institute, Kompolt, Hungary About 80,000 alfalfa plants were examined in 1968 and 20 male-sterile ones were found. After applying critical scoring and hard selection methods, lone almost completely sterile and three partially sterile clones were removed. One of these clones had a sterility system that could be transferred to F progeny in sterile x fertile crosses. According to degrees of sterility 1n BC and BC? progenies,this source of male sterility was considered a nuclear­ cytop1asmit1 system. To study the heterosis effect in 3-way hybrids, seven ms single crosses, three a~netical1y.divergent pollen parents, and their 3-way hybrids,were tested in a fleld experlment. The percentage values of forage yield increase in 3-way h~brids was compared with the two parents. A heterosis effect of only two slngle crosses was outstanding in the 3-way hybrids and positive effects were found only for about 50% of the hybrids. Tests also were made for GCA of ms single crosses using genetically divergent tester parents. It was

81 possible to classify them into different groups according to GCA in which an important role was played by maintainer parents. On the other hand it also was found that seed production of the same cms clone may be very different in relation to bee preference of maintainers. Evaluation for forage yield performance of more than 500 experimental 3-way hybrids showed that about 50% of hybrids outyielded a well adapted synthetic variety and such a type of alfalfa hybrid may give the possibility of 8-10% yield increase compared to improved populations or synthetic varieties. In general, the limited seed yield of ms plants may restrict commercial in­ terest in hybrid production. From this study, however, it can be concluded that selection for better seed production of 3-way hybrids can be affected by selecting cms and maintainer clone parents and also single crosses, respectively. Using the best single crosses in this regard commercial 3-way hybrid seed was produced on a 10 ha field in 1976-78, and under very fav.orab1e conditions in the first and third years the ms strips produced the same seed yield as the pollenizer ones. In the second year at low yielding environment, however, the ms plants produced only 55% seed of that produced by the fertile pollenizer. The best two hybrids are being examined in official experiments for registration. It is also necessary to elaborate a more profitable commercial production practice to decrease production costs especially with utilization of seed propagated parent lines instead of clones which studies are under way.

Effect of Seasonal Variations and Cutting Intervals on Alfalfa Proteins in Egypt A. M. Rammah and Akila S. Hamza Agr. Res. Center-Giza, Egypt This study was carried out on Sonora alfalfa. Samples representing cuts at different growing seasons, i.e. autumn, winter and spring at three cutting schedules, i.e., 30, 40, and 50 cm plant height were analyzed. Nitrogen content was determined. The amino acids lysine and methionine, which are the most important amino acids in feed, were quantitatively determined by a micro­ biological method. Results showed that protein conteryt increased iry winter season then decreased in spring to the same level as ln autumn. ThlS trend was clear in the three cutting systems showing that the protein content was nearly similar in spring and autumn but higher in winter. The plant height during cutting was also found to affect inversely the proteiry content of the plant. The highest protein percentage was found at 30 cm hel~ht and decreased at 40 and 50 cms. Similar results were found in all the studled seas?ns: Lysine percentage of alfalfa protein was not af!ected by ~easona1 varlatlons, but it was affected by cutting schedule: The hlghest lY~lne content was ob- tained from plants cut on 40 cm height ln the three studle~ s:asons. . Methionine content was not affected either by seasonal varlatlon or cuttlng systems. 82 Pathological Studies on the Fungi Associated with Diseased Clover Plants in Egypt Zeinab M. E1-Tobshy, A. M.Rammah, M. A. Abdel-Sattar, M. A. Baraka Agr. Res. Center-Giza, Egypt Isolations from damped-off seedlings, leaf-spot, and decayed seeds of clover plants during two successive seasons during 1977 to 1979 yielded a wide variety of fungi, but by far the most prevalent were Alternaria spp, Rhizoctonia Solani, Sclerotium sp., Fusarium spp., Cladosporium sp., and Aspergillus spp. All these isolated fungi were found to be pathogenic causing varied degrees of infection. Rhizoctonia solani, Sclerotium sp., and Fusarium spp. were widely prevalent and behaved mainly as severe incitants of root and seedling diseases. On the other hand, Alternaria spp. and Stemphy11ium sp. showed to be mainly 1eaf­ spot pathogens producing diverse symptoms. Relatively high perc:ntage of seed infection was resulted from Aspergillus niQer and Stemphy111Um sp. Cross-inoculation experiments using pathogens isolated from infected clover on alfalfa revealed that all tested alfalfa varieties were susceptible to infection with dampin~off and root rot pathogens.

Pathological Effect of Some Egyptian Fungal Isolates on American Alfalfa Varieties Y. E1-Hyatemy1, A. M. Ramrnah 2, H. I. Seif E1-Nasr3 Field Crops Research Institute, Agric. Res. Centre. Giza, Egypt Plant Protection Dept. National Research Centre. Dokki, Cairo, Egypt. Eight alfalfa (Medicago sativa L.) varieties, i.e., Arc, Moapa - 69, Saranac, Dawson, Sirsa#9, Kanza, Washoe and Mesa Sirsa, were found to be susceptible to each of 2 fusaria, 2 isolates of Rhizoctonia solani, Pyth;um sp. isolate and a non-sporulating basidiomycetes fungus. Results indicated that Dawson and Sirsa #9 varieties were little affected before emergence on soil (pre­ emergence damping off). Emerged plants of each variety were affected by each fungus and the effect of the different fungi was similar on varieties ~aranac, Arc, Sirsa #9, Mesa Sirsa, Washoe and Moapa-69. Rhizoctonia solani lsolate (1) caused high severe damage on all varieties. Detection of total phenolic compounds illustrated an increase in content of infected seedlings which.cou1d s~rv~ve. The increase in phenolic compounds due to infection dlffered 1n ltS value from one pathogen to another within the same variety and also among varieties affected by the same pathogen.

83 Effect of Two Root Rot Diseases on Alfalfa (Medicago sativa L.) Grown in Different Egyptian Soils A. M. Rammah, H. Gamal El - Din, H. Sief El-Nasr Field Crops Research Institute, Agric. Res. Centre, Giza, Egypt, Fayom - Faculty of Agriculture, and Plant Protection Dept. National Research Centre, Dokki, Cairo, Egypt A greenhouse experiment was conducted with a local alfalfa variety to investi­ gate the effect of two root-rot pathogens, i.e. Fusarium sp. and non-sporulat­ ing basidiomycete fungus, which was found to cause root rot in alfalfa in Egypt. Four representative Egyptian soils, i.e. clay, salt affected and calcareous, were used in this study. Results indicate that the pre-emergence damping off caused by the tested fungi was relatively high in the clay and salt-affected soils, and the non-sporulating basidiomycete fungus was more effective than the Fusarium sp. in all soils. Both pathogens caused a considerable decrease in dry weight and nitrogen content of survivor plants.

A New Pathogen Non-Sporulating Basidiomycetes Fungus Causing Root Rot of Alfalfa Plants in Egypt H. I. Seif El-Nasr, A. M. Rammah and H. Gamal El-Din Plant Protection Dept. National Research Centre, Dokki, Cairo, Egypt, Field Crops Research Institute, Agric. Res. Centre, Giza, Egypt, and Fayom - Faculty of Agriculture A non-sporulating fungus, not recorded before in Egypt, was isolated from alfalfa (Medicago sativa L.) root-rotted plant samples. The septate mycelium and clamp connections on mycelium cells proved that the fungus belonged to the basidiomycetes. The non-sporulating basidiomycetes fungus has a wide range of growth temperatures with an optimum of 30-35 c. This Egyptian isolate is completely different from the one recorded in Canada by Broodfoot and Cormark (194l). The basidiomycetes fungus attacks the seeds in the soil causina a pre-emergence damping-off. It also attacks seedlings, causing postemergence damping off. The fungus was found to be pathogenic on both local and imported varieties of alfalfa plants, in addition to Egyptian clover (Trifolium alexandrinum). The fungus caused a considerable damage on alfalfa comparable to Rhizocton;a solani.

84 1979

Committee on Preservation of Germplasm

Germplasm collection and maintenance were implemented, as recommended by the 1978 committee. The aspirations of several previous committees were realized, or at least initiated. 'Some recent events contributed to significant improve­ ment in the status of alfalfa germplasm.

One of the sessions of the USDA-ARB (now SEA-AR) alfalfa workshop at Bloomington, Minn., November 16-18, 1976, was entitled "Develop germplasm to avoid genetic vulnerability and to insure preservation of all Medicaqo sources. " This session assessed current and future technology. Recommendations included the development of a program to systematically collect, maintain, and improve Medicago germplasm from all areas of the world. The program was to identify germplasm gaps, plan explorations, conduct genetic and cytogenetic. studies, and cooperate with the Plant Introduction program in preserving and improving foreign germplasm.

The alfalfa Germplasm Resources Information Project (GRIP), an infor- mation system being developed for the National Plant Germplasm System (NPGS), was explained at the 26th NAIC, June 1978. The information system for alfalfa is at the Regional Plant Introduction Station, Iowa State University, Ames, Iowa. Ultimately the system will allow data collection, storage and retrieval, and updating. Record keeping, preparing field books, and filling seed orders will be facilitated. Current NC-7 alfalfa data are available. A GRIP alfalfa technical advisory committee was appointed with W. H. Skrdla as' chairman. Membership of the NAIC committee on Preservation of Germplasm is identical to the GRIP alfalfa technical advisory committee.

In August 1978 a SEA-AR committee met at Beltsville, Md., to discuss in­ creasing seed of alfalfa qermplasm obtained through the PI program and devel­ oping a program to implement the recommendations of the 1976 ARB alfalfa work­ shop. The general objectives of the germplasm development program included the following: identify accessions for seed increase; assist in coordinating seed increases; identify accessions for further evaluation, identify germplasm gaps; assist in planning explorations for seed and Rhizobium nodules; develop and evaluate gene pools and conduct research.

The first meeting of the GRIP alfalfa committee was at Ames, October 11-12, 1978, and included personnel from the Laboratory for Information Science in Agri­ culture (LISA) CSU, Ft. Collins. The committee agreed that the GRIP data bank should be confined to perennial Medicaqo species for the immediate future. The status of data collection on PI's, methods of evaluation, data on varieties and germplasm releases, and a seed distribution center for seed of varieties and germplasm releases, were discussed. It was agreed that alfalfa seed collection proposals from all regions should be reviewed and prioritized by the NAIC/GRIP committee before consideration by regional and national germplasm committees. Current and future foreign and domestic seed and Rhizobium collecti~n proposals were discussed. Proposals for collecting in Turkey, Yugoslav1a, the USSR, and domestic explorations ranked high in priority but added information was needed. Most of the meeting was spent on drafting a list

85 of descriptors (traits) and their definition and research priorities. A list of data for germplasm collectors to obtain was drafted. (A triplicate pres­ sure sensitive form was developed cooperatively and used in 1980.)

Plans were also made at the first GRIP committee meeting for 150 caged seed increases of selected PI's at Reno, Nev., in 1979. Priority was given to PI's that were low in seed supply or viability and had one or more identified economically important traits.

The second meeting of the GRIP committee was October 23-24, 1979, at Ames. M. R. Hanna could not attend the meeting. o. J. Hunt and R. P. Mu~hy retired from the committee. B. D. Thyr was recommended for membership. The list of descriptors and their definitions and priorities were finalized. Costs for evaluating the descriptors were estimated. The committee listed potential locations where each descriptor could be evaluated. A proposal for evaluation of the descriptors is being completed. Plans were made with LISA to send a copy of the report of the meeting, the evaluation proposal, and a cover letter from W. H. Skrdla to NAIC members for information and suggestions.

Fourteen areas for alfalfa collection were proposed and prioritized at the second meeting. Peru-Bolivia-Ecuador and the USSR proposals were approved and funded for collecting in 1980 but were cancelled. Alfalfa was collected in remote areas of Chile in April 1980. A domestic collection in old stands primarily in the NW areas of the u.S. and adjacent areas of Canada is scheduled for July-August 1980. A 1980 trip to China is planned. The Peru­ Bolivia-Ecuador and USSR trips will be reconsidered for 1981. Proposals in various stages of preparation include Spain, central Europe, Yugoslavia, Greece, Turkey, northern India and Pakistan, North Africa, and southern Mediterranean. Ideas for other areas should be relayed to the committee. Breeders are encouraged to donate seed, privately collected from foreign countries, to the PI system.

In 1979, seed increases of the 150 PI's were attempted at Reno. Seed amounts varied from 0 to 72 grams/cage. Poor and delayed germination, small plant size, poor flowering and pollination contributed to low yields even though plants were two months old when transplanted and were grown in cone-tainers. The plans are to increase seed on 150 PI's/year.

Dr. Tom McCoy was employed by SEA-AR as an alfalfa cytogeneticiRt in 1980 to work at Reno, Nevada. Submi tted by:

D. K. Barnes W. L. Lehman R. L. Clark M. D. Rumbaugh J. H. Elgin W. H. Skrdla M. R. Hanna B. D. Tbyr R. R. Kalton W. R. Kehr, Chairman

86 REFERENCES

1. Barnes, D. K. et ale 1977. Alfalfa germplasm in the United states: Its genetic vulnerability, use, improvement, and maintenance. U.s. Dept. Agric. Tech. Bul. 1571.

2. Barnes, D. K. 1980. Alfalfa varieties rece1v1ng favorable action by the national certified alfalfa variety review board 1962-1979. u.s. Dept. Agric. letter to members National Alfalfa Improvement Conference.

3. Elgin, J. H. Jr., et ale 1980. stem nematode and northern root knot nematode resistance ratings for alfalfa cultivars and experimental lines. U.s. Dept. Agric. ARR-NE-7.

4. Gunn, Charles R. et ale 1978. Classification of Medicago sativa L. using legume characters and flower colors. u.s. Dept. Agric. Tech. Bul. 1574.

5. Hunt, O. J. et ale 1978. Improved breeding lines of alfalfa. u.s. Dept. Agric. ARM-W-S.

Conuni ttee on Alfalfa for Dryland Grazing

The report on "Alfalfa for dryland grazing", as summarized at the 26th Alfalfa Improvement Conference, has been forwarded for publieation to the SEAlnformation Center at Peoria, Illinois. We anticipate that it will be accepted and published as a Technical Bulletin during 1981.

The following discussions .make up the paper:

"Alfalfa in Western Grazing Management Systemsn by R. J. Lorenz, Research Leader/Research Agronomist, Mandan, NO.

"Environmental Factors and Alfalfa Persistence in Dryland Pastures and Rangeland" by R. E. Ries, Range Scientist, Mandan, NO.

nDiseases, Insects, and Other Pests of Rangeland Alfalfa" by C. E. Townsend, Research Geneticist, Fort Collins, CO.

nSelection for Drought Resistance in Alfalfan by C. S. Cooper, John Carlson, and R. L. D. Ditterline: Agronomist SEA, Graduate Assistant and " , Assoc1ate Professor at Montana State University, Bozeman, MT.

"Origins of Alfalfa Cult1"vars Used f or 0 ryan1 d Graz1ng" " by M. D. Rumbaugh, Research Geneticist, Logan, UT.

A. C. Wilton

87 CQmmittee on Available Breeding Lines of Alfalfa Release of germplasm or breeding lines is considered by the committee to be of prime importance in the continuing effort of alfalfa improvement.

The committee generally recommends that there should be increased activity in official release of germplasm and that documentation of the characteris­ tics of the material should be adequate enough to provide potential users an indication of its value as germplasm, but does not need to be so extensive as to inhibit the timely exchange of germplasm.

Most of the germplasm releases reported in the 1978 report have been regis­ tered through Crop Science. Registration of these releases is encouraged along with the attendant storage of a sample of the germplasm in the National Seed Storage facilities.

The committee has record of13 germplasm releases since the last report.

Official State/Agency Contact Release Stock Description

Arizona M. H. Schonhorst AZMFA-l Seed Consists of syn 4 seed of a cross between a multi­ foliolate selection from 'Ladak 65' and a vigorous selection from 'Mesa Sirsa' with selection for the multifoliolate charac­ ter in syn 1, 2, 3 plants. (Crop Sci. 19:750, 1979)

Arizona M. H. Schonhorst AZ-Ron Seed Consists of syn 2 seed from 60 vigorous plants with rapid recovery selec­ ted from a 'Moapa' stand, which had been subjected to 36 harvests over a 4-yr period. AZ-Ron maintains higher root reserves dur­ ing high temperature stress periods.

California W. F. Lehman UC-PXl97l Seed Survivors from 20 culti­ L. R. Teuber vars representing 9 germ­ plasm sources (mostly non­ dormant) in a 5-year old variety test in Riverside County, CA were used to produce the syn 2 genera­ tion of a 66 clone poly­ cross. Its main charac­ teristics are high forage yield and persistence in fields with high popula­ tions of root-attacking nematodes. (Crop Sci. 20:288, 1980)

Kentucky Norman L. Taylor V-I Seed Consists of an intercross of 7 Fl clones derived from crosses between creeping rooted plants from Swift Current, Canada, and 'Vernal' (2), 'Rhi-

88 Official State/Agency Contact Release Stock Description zoma' (2), 'Narragansett' (1) and 'Atlantic' (1) plants. Selection of the F1 plants was based on combining ability and creeping root habit. Y-1 Seed Consists of an intercross of 7 yellow flowered F1 clones derived from cross­ es between creeping rooted plants from Swift Current, Canada,and 'Vernal' (2), and 'Rhizoma' (5). Sel­ ection in addition to yellow flowering of the F1 parent was based on yield and creeping-root habit of polycross progeny.

Z-l Seed Consists of an intercross of 30 F1 clones from the crosses indicated in V-I with the non-creeping par­ ents represented by 'Atlan­ tic' (7), 'Narragansett' (5), 'Rhizoma' (9), and 'Vernal' (9). (Crop Sci. 20:115, 1980)

USDA J. E. McMurtrey Beltsville Seed Consists of the syn 2 gen­ J. H. Elgin, Jr. -6 eration of an intercross of 362 plants selected from the non-dormant cul­ tivars 'Bonanza' (154 pl.), 'Florida 66' (128 pl.), and 'Moapa' (80 pl.) after 4 or more years in yield tests in Maryland. Syn 1 plants were screened for resistance to Anthracnose and symptomless plants were used to produce the syn 2 seed. Beltsville 6 is also resistant to Fusarium wilt (74%) and Pea aphid (48%). (Crop Sci. 19:931, 1979) USDA and F. I. Frosheiser Minnesota D. K. Barnes MnFW-H Consists of Syn 2 seed from intercrossing 248 Fusarium wilt resistant plants from 27 winter­ hardy cultivars. (Crop Sci. 20:553, 1980)

MnFW-MH Consists of Syn 2 seed from intercrossing 227 Fusarium wilt resistant plants from 26 moderately winterhardy cultivars. (Crop Sci. 20:553, 1980) 89 Official State/Agency Contact Release Stock Description MnFW-SW Consists of Syn 2 seed from intercrossing 247 Fusarium wilt resistant plants from 20 non-dormant cultivars and germplasm pools adapted to the southwestern United States. (Crop Sci. 20:553, 1980)

USDA and D. K. Barnes MnRH-MH3 Consists of Syn 2 seed of Minnesota D. J. Sarojak a population developed from F. I. Frosheiser 4 cycles of greenhouse N. A. Anderson selection for seedling re­ sistance to Rhizoctonia solani. The base popula­ tion was developed with 69 resistant plants from moderately winterhardy sources. (Crop Sci. 20: 675, 1980)

MnRH-NH3 Consists of Syn 2 seed of a population developed from 4 cycles of greenhouse selection for seedling resistance to R. solani. The base population-;as developed with 119 re­ sistant plants from non­ winterhardy sources. (Crop Sci. 20:675, 1980)

BIC-5WH-RH Consists of Syn 2 seed that was developed by selection for resistance to R. solani in BIC-5lffi. Abo~t 90 resistant plants were intercrossed. (Crop Sci. 20:675, 1980)

The executive committee of NAIC extended the duties of this committee to in­ clude present status of varieties in regard to use and storage in the National Seed Storage Laboratory. It is our understanding that samples of all cultivars that have gone through the Alfalfa Variety Review Board have been stored. This committee needs to determine which of those released prior to the Review Board organization have not been stored.

A number of varieties that are essentially obsolete are still being utilized in the alfalfa industry. There is a need to determine the present status of stock seed of these varieties as well as the present acreage of certified production and possible action that might be taken to discontinue their production.

We recommend the committee be continued and move that the present committee complete the additional assignment as given by the executive committee.

Respectfully submitted by:

R. E. Anderson J. L. Caddel B. A. Melton Real Michaud M. K. Miller E. L. Sorenson R. N. Peaden, Chairman

90 Committee on Variety Certification The 26th National Alfalfa Improvement Conference adopted the "isolation zone" concept, that is, eliminating the isolation requirement for alfalfa where the "isolation zone" is less than 10~ of the entire field to be certified (area of field usually within the isolation strip or border) provided there is a clear line of demarcation between adjacent varieties. This change in alfalfa isolation for the certified class of seed was subsequently adopted by the Association of Official Seed Certifying Agencies, Organization for Economic Cooperation and Development, and Canadian seed organizations where seed is to be used for forage purposes only. The committee reviewed isolation studies conducted in 1978 in both Idaho and California. Repeating the 1977 Idaho anthracnose study between Saranac AR and ~B4 again demonstrated negligible crossing along contiguous borders using leafcutter bees (1, 2). California seed sample studies between spotted alfalfa aphid susceptible but bacterial wilt resistant 'KO-2' and adjacent spotted alfalfa aphid resistant and bacterial wilt susceptible 'Hayden' showed no sig­ nificant changes in levels of SA! resistance from the certified variety where honey bees were used as pollinators (5). These data confirm the isolation zone concept of reduced isolation for the certified seed class.

In a related Idaho study wi th l/l~ mile isolation between Foundation 'Bakertand certified t~J181, no significant differences were observed in levels of resistance for spotted alfalfa aphid, indicating adequate isolation at this distance (1). Additional studies re~arding the isolation distance and field size and shape for the foundation and registered seed classes are needed. Nevertheless, all available studies relating bee behavior and distance in relatively small plantings confirm the necessity of strict isolation in early generation multiplication. Certification land requirement regulations now require three and two years absence of alfalfa for the foundation and regis­ tered classes,respectively. Age of stand continues to be of interest. Age of seed field (1 to 5 years) was not important in the field (including forage yield) and greenhouse performance of Dawson seed lots (lj.). In progeny tests of Vernal foundation seed fields through nine crop years, age of seed field did not affect level of bacterial wilt resistance, incidence of alfalfa mosaic virus appeared to in­ crease with age of stand, and older seed fields appeared to have slightly more plants with purple flowers and fewer plants with yellow flowers (6). The trend to wider diversity (especially dormancy differences) in both narrow and wide based synthetic varieties merits continued consideration of this problem es­ pecially where honey bees have demonstrated pollination preferences (3) in comparison with leafcutter bees.

The Co~ttee recommends that:

1. The present isolation standards for foundation and registered seed classes should be maintained until additional critical data are obtained. Protection from contamination during initial seed gen­ erations is paramount.

91 2. Originators of new varieties specify age of stand limitations for all classes of seed recognized. 3. AdditIOnal studies be undertaken related to 1/4 mile isolation for foundation seed and possible influence of age of stand in more recently developed varieties.

References

! I 1. Brown, D. E., W. R. Kehr, G. R. Manglitz, J. H. Elgin, Jr., and I S. A. Ostazeski. 1979. Isolation distance for foundation i and certified alfalfa fields. Froc. of the 16th Central Alfalfa Improvement Conferenoe. p. 13. l 2. Brown, D. E., W. R. Kehr, G. R. ~nglitz, J. A. Elgin, J~ , and S. A Ostazeski. 1980. Crossing contamination along conti~ous '1 borders of certified alfalfa seed fields. Crop Sci. 20:405-407.

3. Hanson, C. H., ,H. O. Graumann, L. J. Elling, J. W. Dudley, H. L. Carnahan, W. R. Kehr, R. L. Davis, F. I. Frosheiser, and A. W. Honn. 1961~. Performanoe of two-clone Cl'osses in alfalfa and an unanticipated self-pollination problem. Technical Bulletin No. 1300. USDA-ARS. l~. Kehr, W. R. and G. R. Manglitz. 1976. Performance of certified seed lots of Dawson alfalfa. Nebr.'Agr. Expt. Sta. Res. Bul. 277. 5. Marble, Vern L.,W. R. Kehr, O. D. MCCutoheon, W. R. Sheesley, and G. R. Mang1itz. 1979. A study of isolation requirements in alfalfa seed fields pollinated by honeybees. Apis mellifera L.: spotted alfalfa aphid resistance in seed lots from adjacent susceptible and resistant varieties. Proc. of the 16th Central Alfalfa Improvement Conference. p. 14.

6. May, R. G•• D. K. Barnes, R. J. Bula, and C. S. Garrison. 1971~. Charaoteristics of Vernal alfalfa derived from seed fields of increasing age. Agron. Abstr. p. 9l~.

D. W. Graffis V. L. Marble E. L. Grandstaff G. D. Moore M. R. Hanna J. B. Moutray W. R. Kehr D. E. Brown (Chairman)

92 Committee on Standard Tests for Characterizing Disease and Insect Resistance of Alfalfa Cultivars This committee was charged by the 26th Al fal fa' Improvement Conference to complete the review and revision of the standard tests bulletin (ARS-NC-19) orginally published in 1974 with 2700 copies (supply now exhausted). The committee has completed its review and a draft of the revised bulletin has been prepared. The revised bulletin will include several new maps and six new testing procedures as well as an update of previous maps and procedures. Publication, previously projected for early 1979, is now projected for late 1981.

The collection of standard seed lots of the 17 check cultivars recommended in the original standard tests bulletin is available at the Beltsville Agricultural Research Center. In most cases, foundation seed are available; however, registered or certified seed have been substituted where necessary. These seed lots serve as a uniform source for the check cultivars and will be supplied in amounts not exceeding 20 g to those cond.ucting eval uations in which the standard checks are needed.

Requests for seed of the standard checks should be addressed to J. H. Elgin, Jr., USDA-SEA, Field Crops Laboratory, Bldg. 001, BARC~West, Beltsville, MD 20705. Respectfully submitted by:

F. I. Frosheiser R. H. Ratcliffe K. T. Leath E. L. Sorensen W. F. Lehman D. K. Barnes M. W. Nielson J. H. Elgin, Jr., Chm.

93 Nominations Committee Report

The Nomination Committee presented the name of Bill A. Melton, Department of Agronomy, New Mexico State University, Las Cruces, to the Conference. Dr. Melton was unanimously elected as Chairman of the 28th NAIC. The Executive Committee for the 27th NAIC served as the Nominating Committee.

The Executive Committee of the 27th NAIC recommended to the Association of Official Seed Certifying Agencies (AOSCA) that E. T. Bingham serve as alternate delegate from the NAIC on the National Certified Alfalfa Variety Review Board beginning July 1, 1980. He will become delegate on July 1, 1982.

Ike I. Kawaguchi, Plant Breeder, Waterman-Loomis Co., Bakersfield, Calif,., was elected by the alfalfa industry to serve asit'srepr~sentative on the Executive Committee of the 28th NAIC.

Resolution Committee Report

The 27th National Alfalfa Improvement Conference in session• at the Sheraton Hotel, Madison, Wis., on July 8-10, 19~0, adopts the following resolutions.

Be it resolved that:

1. We express our gratitude to the administration at the Un~versity of Wisconsin, to the Agricultural Experiment Station staff, to the Agricultural Extension Service staff,and to the Cooperating USDA staff members for making arrangements for holding this meet­ ing, for the tours,and for the time spent by their staffs.' 2. Specifically, we express sincere appreciation to Ted Bingham for his many special efforts above and beyond the call of duty that made the conference function smoothly. 3. We express our appreciation to the seed companies for providing a luncheon to those in attendance at this conference.

4. We express our appreciation 'to the outgoing officers of this conference for their efforts in organizing an excellent program of diverse subject matter of interest to those conducting re­ search in the many disciplines related to alfalfa.

Respectfully submitted,

Irv Carlson Jonas Miller, Chairman

94 Plans for the 1982 National Alfalfa Improvement Conference

An invitation was received to hold the 1982 conference at the University of California, Davis. In the invitation it was pointed out that California has not hosted the meeting since 1962. The invitation was accepted. The 1982 meeting will be held July 13, 14, and 15.

The locations committee consisted of J. L. Bolton and L. R. Teuber, Chairman.

History of National Alfalfa Improvement Conference

No. Year

1 1934 Lincoln, NE T. A. Kiesselbach H. M. Tysdal 2 1934 Washington, DC A. J. Pieters H. H. Tysdal 3 1935 St. Paul, liN H. L. t~estover H. L. l-lestover 4 1936 Uadison, WI R. A. Brink H. H. Tysdal 5 1937 Chicago, IL R. A. Brink H. L. Westover 6 1938 l1anhattan, KS H. M. Tysdal H. L. Westover 7 1939 New Orleans, LA It. H. Tysdal H. L. Westover 8 1940 Fort Collins, CO L. F. Graber H. L. Westover 9 1942 St. Louis, ~10 L. F. Graber H. L. Westover 10 1946 Logan, UT J. W. Carlson H. M. Tysdal 11 1948 Lincoln, NE C. o. Grandfield H. U. Tysdal 12 1950 Lethbridge, Canada T. H. Stevenson o. S. Aamodt 13 1952 Raleigh, NC R. P. Hurphy o. S. Aamodt 14 1954 Davis, CA o. F. Smith H. o. Graumann 15 1956 St. Paul, UN C. P. Wilsie H. o. Graumann 16 1958 Ithaca, NY C. H. Hanson H. o. Graumann 17 1960 Saskatoon, Canada J. L. Bolton C. H. Hanson 18 1962 Davis, CA E. H. Stanford C. H. Hanson 19 1964 Lafayette, IN R. L. Davis C. H. Hanson 20 1966 Univ. Park, PA H. L. Carnahan C. H. Hanson 21 1968 Reno, NV W. R. Kehr C. H. Hanson 22 1970 Urbana, IL R. R. Hill, Jr. C. H. Hanson 23 1972 Ottawa, Canada D. H. Heirichs C. H. Hanson 24 1974 Tucson, AZ Dale Smith C. H. Hanson and D. K. Barnes 25 1976 Ithaca, NY li. tv. Pedersen D. K. Barnes 26 1978 Brookings, SD U. D. Rumbaugh D. K. Barnes 27 1980 Uadison, WI E. L. Sorensen D. K. Barnes 28 1982 Davis, CA B. A. Melton D. K. Barnes

95 Secretary's Report

The National Alfalfa Improvement Conference (NAIC) is listed as a non­ profit organization by the U.S. Government. A 5 3/4 percent savings account is maintained at the Twin City Federal Savings and Loan, Roseville, Minn. 55113. All monies in the account have been from either surpluses of registra­ tion fees from NAIC national conferences or from interest earned in the account. Transactions during the last two years include:

Balance on hand (6-5-78) 333.60 Income

Interest 6-5-78 to 6-26-80 67.35 Registration surplus 26th NAIC 243.77 311.12 Disbursements (Printing costs) Announcements of regional meetings (3-13-79) 31.00 1978 National Certifed Alfalfa Variety Review Board Report and related materials (8-31-79) 70.75 Notice 27th NAIC and request for papers (12-3-79) 13.60 Information for 27th NAIC Registration and 1979 National Certified Alfalfa' Variety Review Board Report and related materials (4-16-80) 99.20 Program for 27th NAIC (6-26-80) 123.60 (338.15)

Balance on hand (6-26-80) 306.57 During the last two years I have continued my effort to update the NAIC mailing list. In October 1977, the first 'Alfalfa Scientist -- address and activity directory' was completed. It had been my goal to prepare a new directory every 2 years. Unfortunately there was neither time nor money available in 1979 to prepare a new directory. A great deal of interest has been expressed for the NAIC to develop a new directory for 1981. During the last 2 years, the NAIC mailing list has increased by 38 percent.

96 Number Scientists Receivi~ NAIC Information Source 1976 1978 1980

United States 168 225 294 Canada and Mexico 28 51 59 Non-North American 30 53 102 Total 226 329 455 During the last few years, three publications were developed by committees of the NAIC and then published by the U.S. Department of Agriculture. The first publication was "Standard tests to characterize pest resistance in alfalfa varieties", ARS-NC-19 (1974). All 2,700 copies have been distributed, but a new edition will be printed in 1981 and distributed to everyone on the NAIC mailing list. Copies of two other publications -- "Improved Breeding Lines of Alfalfa," ARM-W-5 (1978) and "Alfalfa Germplasm in the United States: Genetic Vulnerability, Use, Improvement, and Maintenance," USDA Tech. Bull. 1571 (1977) are still available as are copies of the "Report of the Twenty­ Sixth Alfalfa Improvement Conference," ARM-NC-7 (1979). All three publica­ tions can be requested from me. I have enjoyed working with Edgar Sorensen and the other members of the 27th NAIC during the last 2 years. I would like to give special re- cognition to all of the staff and students at the University of Wisconsin who did such a superb job at being local hosts for the 27th NAlC. They con­ tributed a great deal to making the conference a success. I am looking forward to working with members of the 28th NAlC. If there are suggestions as to how the activities of the NAIC can be improved, p~ease contact either the chairman, Dr. Bill Melton (Department of Agronomy, New Mexico State University, Las Cruces, NM 88001) or myself. Respectfully submitted,

~c,..,.~-3, t-t-__ V'0-a D.K. BARNES Permanent Secretary, NAlC

97 ~( , -.

Alfalfa Scientists on Alfalfa Improvement Conference Mailing List I ~ ~ United States W.M. Dowler W.F. Hovde J.W. Miller P. Duhigg A.A. Hower, Jr. D.R. Miller R.H. Abernethy G.M. Dunn O.J. Hunt D.K. Miller R.M. Ahring C.R. Edwards S.M. Hurst J.L. Mings K. Albrecht J.H. Elgin, Jr. D. Huset D. Mitten A.J. Alicandro A.H. Ellingboe E.J. Jensen J.A. Mollet J.T. Andaloro F.C. Elliott M.E. Johnshoy C.L. Mondart, Jr. R.E. Anderson R.D. Ensign A.L. Johnson G.D. Moore J. Arledge L. Epstein K.J.R. Johnson L.E. Moser L.E. Arnold D.C. Erwin L.E.B. Johnson J. Moutray K.L. Athow D.W. Evans D. Johnson J.P. Mueller M.R. Azizi K.H. Evans L.B. Johnson R.D. Minson D.C. Bailey S. Ferguson E.R. Jones R.P. Murphy D. Baltensperger G.W. Fick R.R. Kalton B. Murphy S.J. Baluch K. Fishbeck 1.1. Kawaguchi D.L. Nelson L. Barber K.E. Foord W.R. Kehr M.W. Nielson R.A. Barford J.L. Force R.W. Van Keuren M.S. Offutt R.E. Barker H.R. Fortmann H. Kinder R.L. Ogden ~ D.K. Barnes R.V. Frakes W.J. Knipe S.A. Ostazeski I G.L. Barnes A.A. Franklin, Jr. T.R. Knous H. Owens R.F. Barnes H.A. Fribourg J.J. Kolar G.A. Page E. Bartkowski F.I. Frosheiser J. Kugler C.A. Panton L.N. Bass R.H. Garrison L.E. Lanyon W.D. Pardee J .E. Baylor W. Gary H.M. Laude F.D. Parker D.F. Beard J.R. Gerwing A.G. Law B.C. Pass R. Berberet P.B. Gibson K.T. Leath R.N. Peaden B. Bergstrom R.O. Gifford B.M. Leese D. Peck E.H. Beyer D.G. Gilchrist W.F. Lehman G.A. Pederson R.R. Billings D.W. Graffis R.C. Leslie T.M. Peters T. Bingham J.H. Graham R.R. Littlefield M.A. Peterson R. Bitner E.L. Granstaff H.D. Lodon G.G. Poe K.E. Bohnenblust F.A. Gray R.S. Loomis E.F. Poyner J.H. Bouton D.L. Gustine G.M. Loper E.B. Radcliffe M.A. Brick R. Haaland C.C. Lowe R.H. Ratcliffe D.E. Brown D.L. Haeseker R.F. Lucey J.W. Read R.J. Buker D.B. Hannaway H.R. MacWilliam J.H. Reynolds ~ A. Burgoon C.H. Hanson P. Magidman R. Richardson ~I C.C. Burkhardt A.A. Hanson F.H. Mahr C.M. Rincker G.W. Burton L.P. Hart A.P. Mallarino M.L. Risius T.H. Busbice R.H. Hart G.R. Manglitz S.J. Roberts G.R. Buss B.J. Hartman C.L. Marble P. Robnette I Byers Hartman Marcum D.A. Rohweder i R.A. W.G. D.B. "I J.L. Caddel T.L. Harvey G.C. Marten R. Romanko W.M. Campbell J. Hawkins J.M. Martia R. Romero G.E. Carlson G.H. Heichel N.P. Martin L.M. Rommann I.T. Carlson R. Heisey H.P. Massoth R.R. Ronnekamp J.R. Carlson R.G. Helgeson A.G. Matches H. Rothbart J.J. Chatterton R.H. Helmerick N.P. Maxon E.H. Row D.O. Chilcote A.R. Helsel D. P. Maxwell D. Rowe R.L. Clark L.W. Hendrick M. MacCaslin J. Ruegemer R.W. Cleveland G. Hewitt E.F. McClain O.C. Ruelke B.V. Conger E. Hijano T. McCoy M.D. Rumbaugh C.S. Cooper R.R. Hill, Jr. J. McGillis C. Rumberg J.G. Coors L. Hofmann W.E. McMurphy W.B. Rusconi L. Cranfill B. Honrein J.E. McMurtrey J. Ryder-White R.E. Croft C. Holland R.D. Meeks D.K. Ryerson D.G. Cummins E.C. Holt B. Melton R.G. Sackett R. Delaney E. Horber D.W. Meyer R. Salter R.L. Ditterline E.S. Horner R.L. Millar J.V. Santiago D.L. Dodds R.D. Horrocks Miller Seed Co. L.D. Satterlee

98 .. ' ~ __ ..--. U~·S. Cont'd. W.F. Wedin R. Paquin A.V.A. Jacques E.D. Weimortz M.C. Pick A. Jelinovska R.J. Schaeffer R.E. Welty C.F. Quiros H.A. Jonsson M.H. 'Schonhorst F.E. Westbrook J.A. Rascon I.D. Kaehne J.J. Schreck C.E. Whitman C. Richard H. Kontsiton T. Schultz L. Wiesner K.W. Richards A. Kornher J.M. Scriber S.C. Wiggans R.S. Sadasivaiah J. Kristek R. Seaney G.C. Wiklund B.D. Schaber M.A.E. Lattimore R.E. Shade H.T. Wilkinson J.C. Siros J.R. Leclercq A.F. Shaw D. Williams A. Slinkard B. Clement C.C. Sheaffer M.C. Wilson J.A. Sullivan G.M. Lodge R.T. Sherwood M. Wilson M. Suzuki F. Lorenzetti J.R. Sholar T.E. Wilson G. Tan R. Lykora K. Skarien A.C. Wilton L.S. Thompson G.P. Mahoney W.H. Skrdla G.M. Wood D.T. Tomes U. Maki J.E. Skwara S. Yen C.B. Willis Manajen D.H. Smith J.A. Yungen K. Manninger D.L. Smith Non-North American P. Marum D.M. Smith Canada & Mexico v. Meo O. Smith B.W. Allen Milochau D. Smith H. Baenziger A.A. Androwsky C. Moschetti S. Smith J. Belicek J.R. Aragon D. Muldoom D. Sorensen J.S. Bubar F. Auger B. Nagy E.L. Sorensen F.W. Calderon R.E. Avandano J. Nosberger M.D. Stauffer I.M.R.G. Calderson C.B. Banchero M. Obaton M.D. Stauffor T.M. Choo J.M. Blackstock T. Oropeza W.P. Stephen B.R. Christie A.F. Bober A. Panella L. Stockton K.W. Clark J. BOCBa G.R. Peart T.G. Strachota J. Cooper z. BOjtos R.A. Peterson D.L. Stuteville J.G.N. Davidson O.L. Borges J. Picard J.E. Sumberg L. Dessureaux D. Bosnjak J.M. Piskovatski G. Robison C.R. Ellis R. Bournoville J.C. Plan R.E. Swindell M.A. Faris H. Brownlee M.S. Radwan C.M. Taliaferro N. Faust J. Buglos A. Rammah N.L. Taylor R.E. Forrest D. G. cameron J. Read R.L. Taylor R.S. Fulkerson N.E. camron J. Rod W.C. Templeton H. Gasser F. casanas J.A. Rodriguez M.B. Tesar B.P. Goplen F. Charpentier H.H. Rogers L.R. Teuber G. Gorsky M.H. Chaudhary V.E. Rogers R.L. Teweles M.R. Hanna D. Chloupek P. Rotili J.H. Thomas A.M. Harper P. Cregan P. Salisbury B.D. Thyr E.J. Hawn G. Crocker C. Salvatore C. Tiernan D.H. Heinrichs A.G. Davis F.W. Schnell C.E. Townsend R.E. Howarth O.D. De Cordova B.T. Scott M. Trainor L.A. Hunt G.C. Dekock H.I.S. EI-Nasr P.R. Troutman R.B. Irvine U. Demarly B.S. Sidhu G.C. Turner M. Ivanochko B. Dennis U. Simon J.W. Vaccaro P. Jefferson A. Dobias O.R. Southwood N. Vanalfen H.T. Kunelius J.A. Douglas z. Staszewski C.P. Vance T. Lawrence G. Drummond R. Steuckardt A. Vaziri W.C. Leask M.W. Dunrier P.N. Stuart J. Velez G.L. Lees H.S. Easton K. Suginobu R.L. Vetter K. Lesins M.G. Echevarria K. Suginobu D.R. Viands G.E. Mccann M. Falcinelli S. Suzuki F.R. Vigil F. McDowall F. Fujimoto J.N. Tasei L.R. Vough J.S. McKenzie H.G. EI-Din M.N. Terestchenko W-L Research, Inc. R.J. McLaughlin R. Garboucheva P.L. Thomson R. Walgenbach F. Mederick P. Gayraud G.A. Tome C. Walters I.E.I. Medoza D. Gramshaw A. Vachunova M. Walton R. Michaud P. Guy P. Varga J.B. Washko F. Nemec K.M. Ibrahim D. Waterhouse N.D. Waters M. O'Guibord J. Irwin E.C. Wolfe W.A. Way P. Pankiw C.D. Itria R.B. Wynn-Williams

99 National Alfalfa Improvement Conference (NAIC) Mailing List Questionnaire

Returning this questionnaire indicates that you would either like to be added ~ to the NAIC mailing list or that you have an address or activity change. \

1. Name: 2. Date: I, .\ 3. Mailing Address: 4. Office Telephone N.J. -----

5. Present activities with alfalfa: Check appropriate blank(s).

Research Activities Non-Research Activities

A __ Breeding J Administration B ___ Entomology K Extension C __ Nematology L ___ Forage Producer D ___ Pathology M __ Marketing E ___ Physiology N Seed Producer F ___ Forage Production a Student G Seed Production P Teacher H Utilization Q ___ Certification and Variety Protection I Chemical and Quality Analysis R Writer or Publisher S Other ------6. Would you like new variety and germplasm release information? Yes No

For Canadian and USA Scientists Only:

7. Which Regional Alfalfa Improvement Conference(s) would you like to receive information about? Eastern, Central, Western

8. What best describes your employment situation: USDA, __ SAES, U. S. Private Industry, __ Canadian Public, ___ Canadian Private

Note: Please call this questionnaire to the attention of your colleagues and employees who you think should be on the NAIC mailing list.

Return to: D. K. Barnes Department of Agronomy & Plant Genetics University of Minnesota St. Paul, MN 55108

100 U.S. GOVERNMENT PRINTING OFFICE 828·462