Report of the Joint Session

of the

TWELFTH CENTRAL

ALFALFA IMPROVEMENT CONFERENCE

Marrh 3, 1971

St. Louis, Missouri

Reported by

John D. Axtell Y, Secretary

1/ Assistant Professor of Genetics, Deparnnent of Agronomy, Pur­- due University, Lafayette, Indiana

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TABLE OF CONTENTS

General Program Chairman - E. L. Sorensen

Introduction • • • • 1

General commenc. and observations on alfalfa diseases -D. F. Beard . . • . • . • . . . . . . . . • 0 • • • • 1

Breeding alfalfa for Phytophthora root rot resistance -F. I'. Frosheiser, D. K. Barnes and Shyh - Jane Nancy Lu . 5

Can we afford continuing Anthracnose losses in alfalfa -C. H. Hanson, T. E. Devine and S. A. Ostrazeski . • • .• 7

Bacterial leaf spot of alfalfa - D. L. Stuteville • • • 9

Apothecial development and ascospore discharge in Pseudo-peziza jonesii Nannf. - G. Semeniuk • • • . . • • • . 12

Reaction of alfalfa to Pseudopeziza jonesii Nannf. -M. D. Rumbaugh and G. Semeniuk . . 0 • • • • • • • • • • • 13

Alfalfa mosaic virus in alfalfa and selecting for resis-tance - F. 1. Frosheiser, D. K. Barnes and R. D. Wilcoxson 14

Biosystematic evidence on the origin of alfalfa -R. F. Altevogt . . . . . . • . . 0 • • • • • • 16

Bumblebees as pollinators in the breeding of alfalfa and red clover - Ernst Horber . • • . • • . . . • . . • • .• 17

Alfalfa seed production problems in California -10 J. Johnson . . • • 0 0 • • • • 0 • • • • • • •

Alfalfa seed production in the Pacific Northwest - Poten­tials and problems - R. R. Kalton and D. E. Brown • • • •

Report on NC- 7 - W. H. .Sl;rdla

Report on NCR-36 - K. H. Asay

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Report on Ne-B3 - E. L. Sor~sen 35

Report on the National Certified Alfalfa variety review board - C. H. Hanson • • • • • . • 0 • 0 • 0 • 0 • • 0 o. 36

Concluding business . 0 • • • • • • • • • • • • • • • • • 37

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Postscript - New CAlC check varieties • • • • • • • • • • •

Postscript Insect and disease resistant checks .

postscript - Composition of check lots of previous CAlC check varieties . . • • . • .~. • • . • • • • • • • . • •

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Register of attendance . . • • . • . • • . . • • . . • •• 41

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INTRODUCTION

The joint session of public and private alfalfa research workers at the twelfth Central Alfalfa Improvement Conference was convened by chairman E. L. Sorensen at' 8:15 A.M., March 3, 1971 in the St. Louis Gateway Hotel, St. Louis, Missouri.

The report contains summaries of research results, reports of cooperative regional projects and the variety review board, and postscripmon changes in CAlC check varieties adopted by experi­ment station personnel at the March 4, 1971 session of this con­ference. Speakers and their organizations are responsible for the information they have contributed in this report. They should be consulted by those who wish to reproduce the reports, wholly or in part.

Officers for the twelfth Central Alfalfa Improvement Con­ference were as follows: E. L. Sorensen, Chairman, Manhattan, Kansas; M. D. Rumbaugh, Vice-Chairman, Brookings, South Dakota; and J. D. Axtell, Secretary, Lafayette, Indiana.

GHNERAL COMMENTS AND OBSERVATIONS ON ALFALFA DISEASES

D. F. Beard, Waterman-Loomis Company 10916 Barneda1e Drive, Adelphi, Maryland 20783

Since the identification of bacterial wilt, Corynebacterium insidiosum, in 1925, more attention and concentrated effort has been devoted to this alfalfa disease than to any other. Being one of those diseases that depletes stands gradually under most conditions, its real importance has, at times, been controversial. Whether or not Corynebacterium insidiosum works synergistically with other root rotting organisms, it has been observed frequently that U. S. developed varieties, such as Narragansett and Grimm, have persisted better in the presence of bacterial wilt than the Flemish varieties with approximately the same 0 - 2% level of re­sistance. Partly as a result of rather wide-spread usage of wilt susceptible Flemish varieties during the 1960's, a resurgence of severe bacterial wilt damage has been observed in many areas. To be sure, other management practices such as more frequent cut­ting, the increased use of flail type harvesters, and the concen­trated growing of alfalfa on certain farms and fields have aided and abetted the renewed severity of bacterial wilt.

,Unlike the farming of 30 to 40 years ago ~hen alfalfa was a rotation crop on many midwestern farms, a growing proportion of today's alfalfa acreage is concentrated, on intensively operated livestock farms or around alfalfa dehydrators. Such concentrations tend to intensify many disease problems, including the prevalence

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and severity of bacterial wilt. Though a partner in crime, bac­terial wilt frequently has been blamed for stand depletion when other factors may have contributed as much or more to it. All of us are familiar with the test plantings at most midwestern experi­ment statiOBs where, at the end of two to three years, plots of wilt susceptible varieties are depleted entirely alongside wilt resistant varieties with productive stands. Theoretically such a haven should provide an excellent opportunity to select plants higb in bacterial wilt resistance, but more often than not it doesn't. At one of our midwest test sites several years ago we planted DuPuits and WL 202 in alternating 3' x 20' plots in one of our test ranges. By the end of the first full harvest year typical bacterial wilt symptoms were prevalent in the DuPuits plots and susceptible plants could be identified in the WL 202. At the end of two full harvest years the DuPuits plots had thinned to scattered plants - 99% depleted. (The 1953 Yearbook of Agri­culture states that bacterial wilt "does not usually become de­structive until the third crop year") WL 202 still contained a stand, though thinned, that produced near maximum yield. Several hundred of the surviving plants were dug and the roots examined for disease symptoms, particularly bacterial wilt. In addition to some wilt infected roots, many other diseases were observed. One of these was Fusarium oxYsporum, another was Phytophthora megasperma, but many defied identification. From this operation approximately 200 plants with clean roots were saved and rooted cuttings of these were planted in an isolation cage for seed production. The seed was included in the Minnesota bacterial wilt test the following year. Outcome? The new super wilt re­sistant 202 had about 3% fewer wilt resistant plants than its progenitor. Although Tysda1 warned years ago against the hope of building up wilt resistance through natural selection in old alfalfa fields, this situation was designed to b~·di~ferent. : It was not a matter of simple plant selection from an old alfalfa field planted to a single variety. In this case a concentrated source of inoculum was interspersed at regular intervals between plots of a moderately resistant variety. The mowing operation helped spread inoculum across adjacent plots. And, the susceptible plants were killed reasonably fast by bacterial wilt. However, the fact remains that plant e1~ination in both varieties bad been caused by a combination of additional factors equal to or greater in intensity than that of bacterial wilt. Is it not safe to assume, therefore, that many of these same factors have been at work in your alfalfa test plots for years? Undoubtedly they were. However, the classic conclusion bas been that bacterial wilt alone knocked out !hi! susceptible variety but wilt re­sistance save ~ resistant one. Actually, wilt resistance does save some plants but Very often other factors eliminate plants about as fast as bacterial mIt in both resistant and susceptible varieties.

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What are some of these other culprits? One, already mentioned, was Fusarium wilt. I believe this disease is, and has been, more serious than most of us are ,\l7i1ling to admit. It is more destruc­tive in warmer areas than in the more temperate ones. Varieties that do well in maritime climates often deplete rapidly when grown on warmer soils.

Phytophthora root rot is another that has been a problem in the west for years (on heavy, irrigated soils and on soils with "pan" layers) and is now quite serious on thousands of midwest acres in wet seasons. We know that Phytophthora root rot has been around a long ttme but in the last two or three years it has been quite spectacular in several states, particularly in the lower areas offilrms with pot and kettle hole topography. To what extent Corn Belt monoculture has contributed to this problem one cannot say. It is a safe assumption, however, that the increasing compaction of our fertile Corn Belt soils has helped Phytophthora to build up. Then when abnormally wet years appear in the weather cycle waterlogged conditions fan the flames into a prairie fire and Phytophthora has its field day. Isn't it ironic that the most valuable crop for midwest rotations capable of maintaining good soil structure could be eliminated by a disease intensified by the breakdown of soil structure? For alfalfa to remain a soil builder on an incr;aBing acreage of midwest soils, Phytophthora resistant varieties are a must.

Another serious alfalfa disease on the increase in many parts of the country is anthracnose, (Colletotrichum trifoliorum) com­monly referred to in much of the literature as southern anthracnose. My first impression of the potential seriousness of this disease was at VPI in Blacksburg, Virginia eleven years ago. I had heard Dr. T. J. Smith refer to the anthracnose problem in Flemish varieties at that location for two or three years. On this particular visit in September one was able to observe many wilted and dead stems in Flemish varieties with attendant thinning of stands, but rare, or no symptoms, in most other varieties. Since that time the disease has ebbed and flowed throughout the east and midwest. About five years ago it really flared up across much of the mtd­Atlantic area and was observed to be serious enough at Urbana, Illinois to be scored and reported along with yields in the Central Alfalfa Improvement Conference report. Interestingly to me, the typical observations could be made between wilt re­sistant and wilt susceptible varieties at the end of four full harvest years in experiment 467 at the Agronomy South Farm, Urbana, Illinois. Stand percentages varied from 0 for six Flemish varieties to 87% for Vernal and 70% or more for several other wilt resistant varieties. The highly wilt resistant Saranac, however, had a 38% stand compared with 46% for one variety rated about 1/5 as high in wilt resistance as Saranac, but with

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no Flemish germplasm in its background. The real import of anthracnose was illustrated by this test at that location·and over that period of time. Both diseases wer.e important. Which was more important is an academic question, but it is quite ap­parent that resistance to either disease - anthracnose or bacterial wilt - contributed significantly to longevity and forage produc­tion in the presence of both diseases. A similar observation has been made in eastern Pennsylvania where both bacterial wilt and anthracnose have been destructive the last 4 years. It is inter­esting, if not exciting, to speculate on the value of combined resistance to both diseases, even at lower levels than may be considered desirable and attainable for each, or either, by itself.

The nature and effect of synergism would seem to be a chal­lenging and productive area of research for some of our bright young plant pathologists and entomologists working on alfalfa diseases and insects.

In pointing out the seriousness of other root and stem dis­eases, I do not imply that we should compromise our efforts on bacterial wilt. I share the opinion with many others that re­leasing new alfalfa varieties without bacterial wilt resistance should be a thing of the past in this region of the country.

This brings me to a final thought or two after which you will hear from the experts in more detail about some of these diseases and others I haven't mentioned. Breeding for disease resistance has been and will continue to be an increasingly ~portant ob­jective in alfalfa improvement. Resistance to many foliage dis­eases is as yet an unattained objective. The contributions of insect resistance also have been enormous and should be men-tioned here. The inter-relationships of insects and diseases are receiving growing recognition and the economic importance of some of these ' .. is being pin-pointed. In view of these facts, and in view of a changing agricultural environment that puts more and more pressure on our agricultural crops, increasing emphasis will need to be placed upon breeding for disease and insect resistance. The pollution of the environment with toxic chemicals to control diseases and insects is focusing the attention of our entire populace - not merely the agricultural sector - on the controlled usage of such chemicals. Non-chemical control methods that have received a minimum of attention by researchers in the ,ast are being intensified and expanded. In the area of alfalfa improve­ment, as with other crops, breeding resistant varieties takes on added significance. It has been estimated that the equivalent of somewhere between 50 and 60 full-time professional scientists in this country are committed to various phases of alfalfa improve­ment. Approximately 75% of these are devoted to breeding, genetics, physiology and management research. The remaining 20 to 30% are devoted to research on the control of alfalfa diseases and insects. It is interesting to speculate on the course and progress of future alfalfa improvement if these figures were reversed. Maybe these proportions should not be reversed but perhaps they should be

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equalized. Moreover, it "ould be desirable to accomplish this balance "ith additional manpo"er in the deficient areas rather than reductions elsewhere. Should "e see more plant pathologists or entomologists in charge of breeding projects "here breeding for disease and insect resistance is the major objective? One of the greatest contributors to alfalfa improvement in recent years "as a plant pathologist ,.orking almost single-handedly breeding pest resistant alfalfa varieties. I refer to the late Dr. Oliver Smith who developed Lahontan and Moapa alfalfas and had the pea aphid resitant Washoe "ell toward release at the time of his death. For a pathologist or entomologist with some knowledge of plant breeding to say "I can't do it, I'm not a plant breeder" I cite the accomplishment of Dr. Smith as one "ho could and did. He identified the stem nematode problem in some of~major--­alfalfa grm~ing areas in the "est and developed not only a nema­tode resistant variety adapted to those areas, but combined stem nematode resistance with bacterial "ilt resistance and a level of Phytophthora resistance that gave Lahontan persistence values not fully realized until years after its release. In addition, Lahontan was the first and only well adapted variety found to have resistance to the spotted alfalfa aphid when it started to sweep across the southwestern states . This plus factor of spotted aphid resistance was not knmm to exist in Lahontan at the time of its release . Neverthelesij, the combined resistances to several important pests has made this variety a major contribution to western agriculture. In addition, it has served as a source of combined resistance to a multitude of pests that continues to make it useful in the breeding and development of new varieties differing in adaptation. So, pathologists "orking on alfalfa diseases, our hats are off to you, "e "ish you God speed in your challenging endeavors and hope that your numbers will multiply.

Breeding Alfalfa for Phytophthora Root Rot Resistance

F. 1. Frosheiser, D. K. Barnes and Shyh-Jane Nancy Lu ARS and University of Minnesota, St. Paul, Minnesota 55101

The disease caused by Phytophthora megasperma develops in alfalfa growing in poorly drained soils during periods of exces­sive rainfall or irrigation . The rootlets are usually attacked first, rendering the plants at least temporarily unthrifty . If the soil remains wet, the disease wil1 continue until the tap root is rotted. The rot can occur anyplace on the tap root and can extend into the cro"n. When the soil becomes drier, the rotting ceases, and if enough tap root remains, the p l ants may partially recover by producing new secondary roots. This type of adventitious root system is usual1y shal10w and will al1m~ the plant to live, but its yield potential is sever1y reduced, especial­ly during dry periods.

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Reports of Phytophthora damage in the north central states bas been increasing steadily in recent years. This increase is due in part to the fact that alfalfa personnel are more aware of the disease symptoms than in previous years and in part to the prolonged periods of wet soils that have occurred in many areas during the last few years.

In 1968, a field nursery (40' x 110') was established at St. Paul for testing PRR resistance under field conditions. A low­lying area was leveled and f. megasperma-infested soil was spread on the soil before seedbed preparation. Alfalfa was seeded on the area. After the plantlng was 4 weeks old, rainfall was sup­plemented with overhead irrigation to keep the soil at or near saturation for 2-week periods. Top symptoms were apparent 6 weeks after planting. Plants were dug, and those without disease symptoms were selected. The diseased plants were worked into the soil as additional sources of inoculum. A second crop was also established and irrigated like the first to build up inoculum. Similar irrigated trials were established on this same area in 1969 and 1970. Inoculum appeared to be distributed throughout the area, because only about 2 or 3% of the plants in our sus­ceptible checks failed to show damage.

The organism can be readily isolated from infected tissue on corn meal agar containing 100 ppm pimaricin and 200 ppm vancomycin. Pimaricin suppresses growth of non-pythiaceous fungi and vancomycin suppresses bacterial growth, allowing the Phytophthora to grow out on the medium. V.8 juice broth or agar are good culture media for increasing inoculum.

Pure cultures of Phytophthora can be used for greenhouse tests. This is done by cominuting them in distilled water and pouring the mixture over steamed soil or sand prior to planting or after the seedlings have emerged. The soil or sand is kept saturated. Root rot evaluations can be made 3-4 weeks after in­oculation. We have used washed sand in 20" x 34u x 9" zinc coated tanks successfully for seedling evaluations. Once the sand has been infested with Phytophthora, it can be reused several times. Usually, in greenhouse evaluations of young seedlings, only the most resistant plants will live.

No comparisons have been made of the effectiveness and effi­ciencies of greenhouse and field selection procedures. Greenhouse procedures using young seedlings are very rapid. However, the field procedures appear to be valuable, because they allow for the simultaneous selection of Phytophthora resistance and resistance to other soil-borne fungi. Field selection also allows a breeder to select plants with large roots and good vigor.

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A complete variety evaluation for Phytophthora resistance is being conducted in the field at St. Paul. Results should be avail­able by the fall of 1971. None of the available varieties tested have a high level of resistance. Most varieties are very susceptible. Lahontan with about 30% resistant plants has the highest level of resistance among released varieties. However, it appears possible that very low frequencies of resistant genes can be found in many of the available varieties.

Selection for Phytophthora resistance has been conducted at St. Paul for the last tl~O years on four broadbased populations. The resistance in MnP-A, a population derived from Vernal, Minn. Syn. N and Minn. S1o. 0, increased from less than 5% resistant plants to more than 60% resistant plants in two cycles of selec­tion. MnP-B, a population made up of resistant plants selected from winterhardy and moderately winterhardy varieties during variety evaluation tests shows about 50% resistant plants after one cycle of selection. MnP-C, a Lahontan population, showed about 60% resistance after two cycles of selection and MnP-D, a population made up of resistant plants selected from non-hardy varieties showed about 68% resistant plants after one cycle of selection.

Genetic studies on Phvtophthora resistance conducted by Mrs. Lu as part of her M.S. Thesis have indicated that resistance to Phytophthora is apparently due to one tetrasomic gene. The nulliplex condition produces highly resistant plants, the simplex conditions produces less resistant plants and the triplex and quadriplex plants are highly susceptible. Resistance in Lahontan, Vernal, Minn. Syn. N and Minn. Syn. 0 all appear to be controlled by the same gene.

CAN WE AFFORD CONTINUING ANTHRACNOSE LOSSES IN ALFALFAl

C. H. Hanson, T. E. Devine, and S. A. Ostazeski2

Anthracnose caused by Colletotrichum trifolii Bain and Essary is a disease which attacks the stems and crowns of alfalfa plants in Eastern United States and probably in Southwestern United States.

1 Contribution from Plant Science Research DiviSion, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705

1Research Agronomist, Research Geneticist, and Research Patholo­gist, respectively_

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It thins stands, weakens overwintering capacity, and reduces yield and life of the stand. At least 4 million acres of alfalfa in eastern half of the United States alone are affected by anthrac­nose.

Recently we released five highly resistant populations to alfalfa breeders. They were ~eveloped by recurrent phenotypic selection and were identified as follows: Beltsville l-An4, Beltsville 2-An4, Beltsville 3-An4, MSA-CW3An3 and MSB~CW5An3. Anthracnose resUtance in the first three was developed by three cycles of selection in Glacier, Saranac and Vernal, respectively. Two cycles of selection were used to develop MSA-CW3An3 and MSB-CW5An3. Selection in the last two populations had been pre­ceded by 16 to 18 cycles of selection in our "A" and "B" pools for resistance to other disease and insect pests, including bacterial wilt, common leafspot, leafhopper yellowing and rust. These populations represent a wide array of germplasm, and con-tain from 59 to 87% plants highly resistant to anthracnose. Adapted varieties can be developed from each of these populations for specific areas by field selection of adapted types with top performance.

We also distributed seed of two moderately resistant popu­lations, Beltsville 4-An2 and Beltsville S-An2, which traced chiefly to introductions from Mexico and Peru, respectively.

We are increasing seed of the releases so as to establish field tests in different regions of the United States to determine the contribution of resistance to C. trifolii to persistence and yield of alfalfa. These tests also will a~ford an opportunity to discover whether there are forms of this species or of other species of Colletotrichum to which the improved population might be susceptible.

The rapid development of anthracnose resistance in the fore­going populations was made possible by the combined use of con­trolled laboratory facilities, an effective breeding procedure, and a new and simplified technique for inoculation with the disease. The use of recurrent phenotypic selection, a form of mass selection, permitted screening of large numbers of plants for resistance (140,000 in all) in our Beltsville program to isolate resistance and to preserve genetic variation for characters that were not selected. About 200 resistant plants within each population were intercrossed in each cycle to initiate a new generation. Preserving genetic variation in original populations by this means increased the value of improved populations to alfalfa breeders. With the use of dry inoculum technique for infecting plants, which "(-las developed by S. A. Ostazeski and co­workers, large numbers of alfalfa seedlings could be inoculated precisely with the disease and at low cost.

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Additional information on the anthracnose resistance program at Beltsville can be obtained from citations given below. The last two were issued by the Plant Science Research Division, Beltsville, Maryland, on December 23, 1970.

Barnes, D. K., S. A. Ostazeski, J. A. Schillinger, and C. H. Hanson. 1969. Effect of Anthracnose (Col1etotrichum trifolii) Infection on Yield, Stand, and Vigor of Alfalfa. Crop Sci. 9:344-346.

Ostazeski, S. A., D. K. Barnes, and C. H. Hanson. 1969. Laboratory Selection of Alfalfa for Resistance to Anthracnose, Co1letotrichum trifolii. Crop Sci. 9:351-354.

Campbell, T. A., S.·A. Ostazeski, and C. H. Hanson. 1969. Dry Inoculum for Inoculating Alfalfa with Colletotrichum trifolii. Crop Sci. 9:845-846.

Devine, T. E., C. H. Hanson, S. A. Ostazeski, and T. A. campbell. Selection for Resistance to Anthracnose, Colletotrichum trifolii. Submitted to Crop Science for publication.

Hanson, C. H., T. H. Bushice, R. R. Hill, Jr., O. J. Hunt, and A. J. Oakes. Directed 11ass Selection for Improvement and Conservation of Alfalfa Germplasm. Submitted to Crop Science for publication.

Notice of Germplasm Release of Five Alfalfa Populations (Beltsville 1-An4, Beltsville 2-An4, Beltsville 3-An4, Beltsville 4-An2, and Beltsville 5-An2) with Resistance to Anthracnose.

Notice of Release of Multiple Pest-Resistant Germplasm Pools MSA-CW3An3 and MSB-CW5An3 to Alfalfa Breeders .

BACTERIAL LEAF spar OF AJ2ALFA

D. L. Stuteville Department of Plant Pathology

Kansas State University, Manhattan

Bacterial leaf spot of alfalfa (Medicago sativa L.) caused by Xanthomonas a1fa1fae (Riker, Jones & Davis) Dows. (3) was first noted in 1930 at Madison, Wisc., in a cultivated experimental nursery (6). It was next reported in 1938 in an Agronomy green­house at Manhattan, Kans. (4). The following year the disease was observed in experimental fields at Manhattan. In 1948 it was found at Poona, India, on the College Farm(5). In June, 1956, it was noticed in a space-planted nursery at Ames, Iowa (1). In September, 1956, !. alfa1fae caused light damage in many fie1mof alfalfa in central Iowa (2).

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To my knowledge the disease has not been reported from other areas although it is undoubtedly more widespread than re­ported. I observed it in 1967 in southern Oklahoma. Scattered reports suggest that bacterial leaf spot is not a serious disease of alfalfa, but interest in!. alfalfae in Kansas was renewed in 1964 by severe losses of breeding material at the Ashland Agronomy Farm near Manhattan (7). More than 50% of established first-year transplants were killed in one space-planted nursery. Bac­terial leaf spot has also greatly reduced seedling alfalfa stands at the Ashland Farm when abnormally warm weather prevailed after seeding. The disease is widespread in Kans$ but serious losses have been noted only at Ashland Farm.

In the field, stem lesions usually originate on the south side of the stems, the direction of the prevailing winds, and the disease has been more prevalent on lighter (sandy) soils. Those observations coupled with the predominance of disease reports from cultivated space-planted nurseries suggests that windborne and/or wind and rain driven soil~articles, carrying!. alfalfae cells, wound and, thus inoculate, plants. Obviously, space­planted nurseries are observed more closely for diseases but at Ashland Farm the disease was severer in the space-planted nurseries than in drilled stands after they became tall enough to impede soil blowing.

The host range of X. alfalfae is restricted to a few members of the Leguminosae. Hosts found susceptable by artificial ino­culations in the greenhouse included garden pea, white and yellow sweetclover, black medic, crimson clover, common vetch, and 'Clark' soybean (7). Garden pea was more severely affected than alfalfa. I have not searched for x. alfalfae on those hosts in nature ex­cept I found no suspicio~s symptoms on soybeans growing adjacent to infected alfalfa at the Ashland Farm.

Although bacterial leaf spot is a minor disease of alfalfa, it seriously hindered the alfalfa improvement program at Kansas State by destroying seedling stands and mature plants that were otherwise superior breeding material. Therefore, further studies, including a mass screening program, were initiated to select re­sistant plants--subjects of this presentation. The methods des­cribed are simple and they have let us identify improved resistance.

Xanthomonas alfalfae is much more stable in culture than are most plant pathogenic bacteria. A culture maintained on potato­dextrose agar slants with frequent transfers was virulent after 6 years. We have recovered the bacterium from diseased alfalfa leaves collected in the field and stored at room temperature for 5 years. We maintain cultures in water. Three loops of the bac­terium from an agar slant is put in 100 ml of sterile, distilled

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water in a bottle and capped. We store in a refrigerator but that probably isn't necessary.

Inoculum consists of potato-dextrose broth (PDB) with 2-3 days of bacterial growth at room temperature or above. Optimum growth of X. alfalfae in culture occurs at about 30 C. We prefer fresh, homemade PDB to dehydrated preparations. To prepare, cook 200 g of chopped potatoes in 1 liter of water, strain the broth through 2 layers of cheesecloth (discard potatoes), dissolve 20 g glu-cose in the broth and add the necessary water to regain the I liter volume. Pour 100 ml of PDB per 2S0-ml erlenmeyer flask, plug with cotton, and sterilize. As needed add 2-3 loops of Bacteria and place on shaker for 2-3 days. For stem inoculations with needle, we use undiluted; for foliar spray applications we dilute 50 fold.

We have inoculated plants at various stages of growth using several methods and have settled on this procedure: use plants in a stage of active vegetative growth. We apply inoculum at about 80 psi pressure with a DeVilbiss atomizer No. 152 held close enough to plants to cause some water soaking. This guaran­tees entry of the bacteria into the plant and eliminates need for a moist chamber following inoculation. Carborundum added to the inoculum aids penetration if sufficient air pressure isn't available. We keep plants 10-14 days at 24-28 C (28 C is prefer­able) and rogue. Symptom development has been more predictable in a growth chamber than on greenhouse benches, probably because the chamber has higher temperature and higher relative humidity. The chamber consists of an Army surplus, walk-in, field refri­gerator with a 24-hr photoperiod of fluorescent lighting (about 500 ft-c).

Susceptible plants have large spreading water-soaked lesions, whereas stem and leaf lesions on the resistant plants are maaller and include little, if any, watersoaking. The necrotic centers of the lesions in resistant plants usually are darker than those in susceptible plants.

After mass screening, we again inoculate the remaining plants as described and, in addition, puncture the stems at several inter­nodes with a dissecting needle dipped in inoculum. We also in­clude known resistant and susceptible clones in every test as guidelines for selection.

We have observed no variability among several isolates of I· alfalfae. All cultures used for screening were collected in areas more than 100 miles from Manhattan. So far the selected plants have remained resistant during natural epidemics at Manhattan.

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None of 34 alfalfa varieties evaluated was considered resistant to!. a1fa1fae, but each contained plants that showed varying degrees of disease severity, suggesting that progress through recurrent selection is possible.

Three cycles of recurrent selection in 'Kanza' alfalfa for resistance to X. alfalfae increased the number of resistant plants in the population from 0.08% to over 95%.

References

1. Brigham, Raymond D. 1956. Bacterial leaf spot of alfalfa in Iowa. Plant Disease Reptr. 40:830.

2. Brigham, Raymond D. Xanthomonas alfalfae.

1957. Stem lesions associated with Phytopathology 47:309:310.

3. Dowson, W. J. 1943. On the generic names Pseudomonas, Xanthomonas, and Bacterium for certain bacterial plant pathogens. Trans. Brit. Myco1. Soc. 26:4-14.

4. Melchers, L. E., H. Fellows, D. B. Creager, and C. H. Ficke. 1940. Cereal and forage crop disease investigations. In Kansas Agr. Exp. Sta. Tenth Bien. Rept. 1938-1940. pp--. 105-106.

5. Patel, M. K., Y. S. Kulkarni, and G. W. Dhande. terial leaf-spot of lucerne. Indian Phytopath.

1949. Bac-2:166-167.

6. Riker, A. J., F. R. Jones, and Marguerite C. Davis. 1935. Bacterial leaf spot of alfalfa. J. Agr. Research 51:177-182.

7. Stuteville, D. L. and E. L. Sorensen. 1966. Distribution of leaf spot and damping-off (Xanthomonas a1falfae) of alfalfa in Kansas, and new hosts. Plant Disease Reptr. 50:731-733.

APOTHECIAL DEVELOPMENT AND ASCOSPORE DISCHARGE IN PSEUDOPEZlZA JONES II NANNF. !.I

G. Semeniuk '1:.1

(Abstract)

Because Pseudopeziza jonesii usually fails to sporulate in

1/ . - Agricultural Exper~ment Station Project 230, South Dakota

State University, Brookings.

!/p1ant Science Department, South Dakota State University, Brookings, South Dakota 57006.

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13

culture, field-infected alfalfa leaves were used to provide apothecia for a source of ascospores for plant inoculations and for a determination of some features of the pathogen. Such leaves were hand-picked from plants in late June or early July in wes­tern South Dakota where other leafspots usually are absent. The leaves were air dried after collection; thereafter, they were wetted and dried flat betweel'. blotting paper, and secured in numbers of about 30 (all leaves with sides either up or down) between 4 x 5 in. plastic window-screening sewed together with nylon thread. The leaf-carrying plastic screens were then placed (leaf topsides all up) between heavy metal screens and set out­doors in early August on the open ground in the shade of a building in Brookings. Mature apothecia began to appear toward the end of August in 1969 and toward the end of October in 1970. The time difference was due to a weather difference between the two years; i.e., in rain and dew. The same effect of weather was seen in similar appearances of mature apothecia in leaf­carrying plastic screens placed in early August on open ground at different locations westward across the state. Mature apo­thecia appeared by the end of September or early October at some locations and not until late spring the following year at other locations. In the greenhouse (20 C), apothecia began to form within 3 weeks on leaves placed directly on moist sand, and with­in 1 week l~en leaves beforehand were held 3-4 weeks on moist sand in plastic boxes at 4 or 12 C. Most leaves so treated faile4 to mature apothecia, or matured only a few of them, be­cause mold and bacteria usually overgrew and decomposed the leaves and the developing apothecia.

Mature apothecia discharged ascospores in atmospheres of 100-97.5% r.h., and on drying when wetted. Ascospores were dis­charged for distances up to 1.6 cm maximum, with most spores being singles, not doubles as with~. medicaginis. In a moist atmosphere (near 100% r.h.) leaf infection took place within 24 hr. at 43F, 8 hr. at F, and 6-8 hr. at 68F; no infection oc­curred at 90 F. Symptoms of the disease began ·to appear after 2 weeks. at 68 F in the greenhouse.

REACTION OF ALFALFA TO PSEUDOPEZIZA JONESII NANNF.!I

by M. D. Rumbaugh and G. Semeniuk!1

(ABSTRACT)

Twelve alfalfa clones selected on the basis of field reaction

11 . - Approved for publ1cation by the Director, Agricultural Experiment

Station, South Dakota State University, Brookings, as Journal Series No. 1000.

21 - Professors of Plant Science, South Dakota State UniverSity, Brookings,

t' ___ .a..L ..... _t __ ..... _

14

to Pseudopeziza 10nesii Nannf. to1ere cross- and self-pollinated. A greenhouse test of response to the same pathogen showed that both general and specific combining ability effects were important in this test. Transgressive segregation for resistance occurred in all crosses. Field reaction scores to the pathogen were not highly correlated with the reaction to the same fungus in the greenhouse. Differences in score criteria in the two cases may have been the· cause.

Frequency distributions of plant and plot mean scores were skewed toward the resitant end of the response scale. The score criteria perhaps should include lesion abundance as a factor in host reaction. The observed error variances were of larger mag­nitude than believed necessary probably due to non-uniform spore discharge over the bench test areas. The test will be repeated two more times prior to final interpretation.

ALFAJ3A MOSAIC VIRUS IN Au!ALFA AND SELECTING FOR RESISTANCE

F. I. Frosheiser, D. K. Barnes and R. D. Wilcoxson ARS and University of Minnesota, St. Paul, Minnesota 55101

Alfalfa mosaic virus (AMY) occurs worldwide and some strains have been found to occur in at least 49 species in 12 plant families including 19 species in Leguminosae. Occurrences of 27% infected plants in one-year-old fields to over 80% infected plants in older stands, have been observed in Minnesota, Wisconsin, and Rhode Island.

The AMV complex consists of many strains which differ in virulence and symptomotology. Symptoms in alfalfa range from none to slight mottling, yellow streaking and/or necrosis, ac­companied by leaf contortion and often stunting. Forage yield reductions in studies with limited numbers of clones and AMV strains, have ranged from 11 to 30%. Some strains can kill some alfalfa genotypes by causing root necrosis. Some strains also cause depression in rooting of cuttings. Percentages of well rooted cuttings varied from 9 to 93 in virus infected clones and from 68 to 88% in the same clones, but virus free.

AMV is transmitted by aphids, through seed, or mechanically. The pea aphid (Acyrothosiphon pisi) is the major vector in alfalfa. Data are not available that compare the incidence of AMV in pea aphid susceptible and resistant varieties.

We believe that seed transmission usually provides the initial infection in a field, because about 85% of 56 commercial seed lots tested contained 0.2 to 6.0% AMV infected seeds. In experimental

.'

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15

seed increases from virus infected plants over 20% infected seeds have been observed. Mechanical transmission can occur in the field, but we believe aphid transmission is most important in the field.

AMV can be transmitted mechanically by gently rubbing infec­tive plant sap on silicon carbide-dusted leaves. Fingers, pipe cleaners, or gauze pads can be used to transfer the infective sap. Of these, pipe cleaners appear the most effective. Since many AMV strains produce no symptoms in infected alfalfa plants, indicator plants are used to detect virus infection. Sap from the suspected alfalfa plants is rubbed on the pr~ary leaves of Bountiful bean (Phsseolus vulgaris). If the donor plants are in­fected, local, necrotic lesions, or small chlorotic or necrotic rings appear on the inoculated bean leaves. The latter are usually accompanied with systemic infection. Serological techniques are also used to detect AMV infection.

Just as alfalfa populations contain a wide range of plant geno­types, the AMV complex contains a larger number of strains. This was illustrated when 16 differential alfalfa clones were inocu­lated with 43 AMV isolates, 28 AMV strains were differentiated. A few alfalfa clones have been resistant to all isolates tested to date.

Genetic studies have been conducted on the host-strain re­action of 4 strains of AMV. The results indicate that resistance is dominant and res~stance to anyone virus strain is controlled by only one or two genes. However, it appears that the various resistant genotypes are interrelated. For example, resistance to isolate R7 appears to be controlled by one dominant gene A and isolate WI appears to be controlled by the presence of two domi­nant genes A and C.

We anticipate that once we learn more about the inheritance of resistance and the relative virulence of the AMV strains, it should be possible to breed AMV resistant varieties. We already have developed a mabod for inoculating large numbers of 8-10 day-old seedlings with AMV. The procedure consists of atomizing inoculum into the alfalfa cotyledons or leaves under 35-40 psi with an artists air brush. We hope that it may be possible to isolate multiple virus strain resistance by inoculating plants with a mixture of AMV strains and selecting non-infected plants.

Electron microscopy studies on our ~ strains are in progress. AMV particles range from short rods with rounded ends (baciliform) to spheres. Particle diameter ranges from 17 to 30 mu and length from 20-100 mu. To date virus particles have been observed only in the cytoplasm of parenchyma cells. Studies are being conducted

16

to determine (a) what tissues and organs harbor the virus; (b) the association of the number of virus particles in the floral parts with transmission of the virus through the ovules and through the pollen and (c) compare characteristics of different strains and correlate with their infectivity in alfalfa clones.

I Biosystematic Evidence on the Origin of Alfalfa

by

2 Raymond F. A1tevogt Washington University St. Louis, Missouri

This is a taxonomic and ethnobotanical study of the origin and variablility of alfalfa, the most important forage legume of the temperate world. New methods were developed in this study to measure precisely variable characters of taxonomic valUe Analysis of these new data suggested the directions and patterns of phylo­genetic changes. The interaction with man, his animals and the flora of the steppes and meadows, of which alfalfa is an impor­tant component, is considered. Climatic changes and subsequent development of new texa also altered alfalfa's evolution.

Understanding the origin of alfalfa is an aid, if not a highly significant guide, to plant improvement. Today there is a major gap between botanical classification, on the one hand, and the work of quantitative geneticists and agronomists on the other. This survey begins to bridge that gap.

Live plants and herbarium specimens of over fifty species of Medicago were studied. Herbarium specimens made from the live collection are deposited in the Missouri Botanical Garden Herbarium. Particular attention was given to morphological differences in dissected flowers, i.e., standard petals, the basal lobe of the wing petal and calyx trichomes. Camera lucida drawings were made

I Note- Abstract of Dr. Altevogt's presentation not available. With

2

his permission, the abstract of Dr. Altevogt's Ph.D. dissertation entitled "Origin and Variablility of Alfalfa: A Biosystematic Survey of Perennial Medicago" is presented in lieu of the CAlC' abstract. Reference: Dissertation Abstracts International, Vol. 31, No.4, page 1755B, October, 1970.

Present address: 9742 Lookout Drive, St. Louis, Missouri.

17

from these to provide objective evidence of the phylogenetic trends of the perennial species. Cytology and modern palynolo­gical techniques provided additional information.

Alfalfa is the hybrid product of twenty to fifty or more pere­nnial species of Medicago. There is no distinct boundary between alfalfa and its weed and its t'lild relatives. Many species and ecotypes continue to introgress into cultivated plants. Two species aggregates and one species are recognized as the primary progenitors. One, the ~. falcata aggregate, typically has sickle­shaped pods, yellow flowers and broad standards. Its center of diversity is in and about the Balkans although many varieties are disjunct in Inner Asia. The second, the~. sativa aggregate, is of particular interest because of its atypically blue flower pigments and narrow standards. Most are from Asia, but there is no single center of diversity. Medicago glutinosa is a third pro­genitor having large-glanded trichomes. It is limited to regions about the Caucasus. The methods here developed can be used to define more accurately the many varieties and natural ecotypes and taxa which inter-bred with alfalfa.

Bumblebees as Pollinators in the Breeding of Alfalfa and Red Clover

Paper presented by Ernst Horber, Department of Entomology, Kansas State University, Manhattan, Kansas as the Twelfth Central Alfalfa Improvement Conference,

St. Louis, Missouri, March 3, 1971.

1. Introduction

This report covers studies on the possibility to domesticate wild bees for pollinating purposes. These studies were initiated with bumblebee species since some of them offer the distinct advantage of having a longer tongue than the honeybee and there­fore are able to pollinate redc10ver and other legumes of eco­nomic importance to which the honeybee usually is not attracted.

Pollinators take a peculiar position among phytophagous in­sects because they are beneficial rather than pests. Studying insect-hostplant relationships of pollinators is as fascinating as searching for hostplant resistance to insects, or investigating gall-making insects. Satisfaction in working with pollinators richly compensates for the difficulties involved with simultaneous­ly tackling two apparently widely distinct fields as Entomology and Botany. While we carefully avoid trespassing into 'foreign territories' as we carryon our research within the limits of separate departments at our present-day universities, our pollinators are allowed to fly and work freely in nature, which is only one, but really universal "department".

18

During September, 1970, I celebrated my first decade of work with bumblebees. It started quite modestly in my backyard in Zurich, Switzerland. I was working over my compost heap, when I uncovered a handful of wildly humming queens of Bombus hypnorum L. which apparently, shortly before, had taken their winter quarters there. This cue prompted studies on possibilities of overwintering bumblebee queens in the refrigerator where they were protected from the harsh climate and aggression of enemies (Horber 1961). Next spring the overwintered queens started colonies in wooden boxes which I provided in a greenhouse. I obtained best results when I followed essentially the method by Hasselrot (1952); however, after moving the boxes to a rearing room, 1 gradually increased the temperature to 300 e and then maintained it constantly. This high temperature made possible avoiding use of nesting material and allowing close observations of every step in colony development without disturbing the colony: from production of wax to forming the honeypots and eggcups, to appearance of the first brood, the pygmy set of first workers, the drones and finally, at the climax of the colonies, the hatching of the stately queens.

Among the nearly 30 species of European bumblebees, 1 was primarily interested in the long tongued species ~. hortoru~, agrorum, and si1varum; however, 1 decided to switch to the group of B. hypnorum, lapidarius, lucorum and terrestris because these species are capable of building larger colonies.

I worked out a method to breed bumblebee colonies continuously throughout thewho1e year by starting new colonies whenever a new crop of queens hatched. The surplus queens were stored in the refrigerator as a reserve for later use. I finally succeeded several times in producing colonies of~. terrestris with more than 1500 individuals.

Concurrently I noticed a distinct shift in sex ratio. in favor of drones (d). Subsequently, 1 studied the feasibility of placing the males, which, when in great numbers burdened the economy of the colonies, to work in my greenhouse and in field cages, where they pollinated red clover and alfalfa very satisfactorily(Table 1). These bumblebees released the tripping mechanism and did not demonstrate avoidance of alfalfa in contrast to the honeybee.

2. Material and Methods

a. Rearing of bumblebees

We initially used wooden boxes for rearing of bumblebee colonies. They consisted of two intercommunicating compart­ments (25x25x25 cm) one of which served as a feeding place where

19

syrup or diluted honey was exposed, and the other to hold the nest. The nesting compartment was filled with moss, fine grass, or tailor's cotton, in the center of which was placed a hollow sphere of cellulose wadding (Hasse1rot 1952). We gradually developed a new type of nest-box made of asbestos-cement (~Eternit') of 26x16x15 em which inter-communicated through the flight hole with a flight-and feeding-cage (26x16x32 em). This asbestos-cement with 6 mm wall strength proved resistant to dry and wet heat and could therefore be cleaned and sterilized very effectively with-out warping. No nesting material was necessary when temperature was maintained at 300 C. Only a piece of wooden board (12xI2x'2 cm) was placed inside the nesting compartment. A 12 cm long hooked screw made it possible to lift this board together with the hive out of the box.

b. Separation of drones.

Separation of drones from workers was expedited because, in the course of our studies, we noticed that bumblebee flight could be stopped by switching from white light to a red, darkroom bulb. The workers crawled along the walls under the dark red. lights, while the drones were able to fly as long as they kept their forelegs in touch with the cage walls. By taping a band of plastic tape of ca. 3 em width inside and halfway up the flight cage, the workers were forced back and only the drones reached the screen which covered the flight cage, where they could be collected by the dozens or hundreds at a time either by hand or with a small bottle.

c. Pollination studies.

The fieldcages utilized consisted of wooden frames covered with Saran screens (mesh 20x20). The bigger frames were collap· sible ~'order 20 save storage space; when assembled they covered an area of 5 m and were 1 m hiah. Since they did not allow walk­ing in, a small door was inserted on one of the smaller sides. The smaller cages measured about 1 m and offered acess through a sidedoor.

The pollination studies were conducted in conjunction with a breeding program, including crossing of land varieties, selection of strains for resistance to nematodes and for tetraploidy. There­fore the plant material was inhomogenous aDd did not allow the setup of orthogoral comparisons between the efficiency of different bumblebee species. The redclover stand was established in the summer previous to the crossing and pollination studies in plots of the size to accommodate the bigger cages described above. How­ever, the survival of plants in adjacent plots was unpredictable according to weather conditions and impact of diseases (e.g. Sclero­tinium trifo1iorum) and nematodes (Ditylenchus dipsacum).

20

The studies in the greenhouse were conducted in small com­partments with screened windows, allowing access through swing doors, which could be locked, in order to avoid unnecessary traffic and exclude undesired visitors. The plants were potted and could be removed when pollination was achieved.

In both studies in the field cages as well as in the green­house, the heads to be inspected for seed set were marked, with strings attached to the stems. Usually 50 heads were deSignated, harvested and separately stored in small paper envelopes until inspection.

Percentage of seed set was obtained by counting of all flowers and seeds of these heads individually. The heads were rubbed through a 20 x 20 mesh saran screen. The number of bumblebees released in the cages depended on the number of flowering red-clover heads available. Usually we attempted to achieve a ratio of 1 bee to 10 heads or roughly 1 bee to 1000 flowers. The num-ber of flowering heads and surviving and active bees was controlled at regular intervals and adjustments were made through release of additional bees when necessary. Notes were taken on the activity and behaviour of the different bumblebee species, and sexes (~, ~, ~ respectively. Robbing behaviour was especially watched and note!.

3. Results

The comparison within bumblebee species is not based ,on an orthogonal layout due to the facts described under 2c. Seasonal fluctuatio~have to be considered; the 1966 harvest showed a poor seed set in all samples available. The different entries for a single year in Table 1 represent data from different cages, locations, redclover strains, f\owering time, and therefore can­not necessarily be considered as replications in a strict sense.

The seed set data presented in Table I suggest that we may expect satisfactory seed set in red clover pollinated by bumble­bee drones. The average seed set was lowest with B. lucorum, especially in '1966. The differences between plants pollinated by workers and drones of !. terrestris are clearly in favor of drones although it would be desirable to have comparable data also ~rom other years than 1966. Only one sample of tetraploid red clover pollinated in 1969 by drones of B. terrestris was avail­able and it did not give satisfactory seed set. As a whole the seed set obtained in cages with drones of B. agrorum, B. hypnorum, !. lapidarius, ~. silvarum, !. lucorum, !.-terrestris compared favorably well with the seed set observed in the field which was achieved by uncontrolled pollinators.

4. Advantages of bumblebee drones for pollination.

There are several reasons why bumblebee drones should be put

21

to work as pollinators. Firstly, they are usually bigger and of more uniform body size than'the workers (~); therefore, even tongues of the medium-tongued species are longer and better adapted to obtain nectar from long and narrow corollae tubes, as in the case in red clover. Secondly, drones do not require hives because they stay on flowers during the night and may survive weather condi­tions occurring during the late summer and early fall for several weeks; therefore, no domiciles which would only attract a great number of enemies (rodents, ants, earwigs, etc.) are required. Thirdly, since drones lack a sting in contrast to workers and queens, the personnel in charge of breeding work and which have to take care of labeling and watering, etc. of the plants, may work unmolested in the narrow compartments and cages used for crosspol1inations. Fourthly bUmblebee drones as well as workers, within a few hours get acquainted with and accustomed to limited flight space available in greenhouse compartments and field cages after which they do not try to escape and hereby avoid lOSing strength from constantly battering to the screen and glass panes as honeybees do trying to escape. Finally, by utilizing only drones as pollinators, the workers may be retained in the nest, where they rear larvae and, in case the queen has died, produce eggs, hereby continuing the production of drones; and the workers are kept inside the hives protected from inclement weather.

The drones do have to overcome a higher temperature threshold of several degrees C for pollinating activities, but this does not interfere with efficiency in greenhouses or in field cages. For the pollination of alfalfa even relatively short tongued species (e.g. B. humilis) work satisfactorily. Therefore, those species which inherently are capable to build large colonies are to be preferred over those having long tongues.

5. Summary and conclusions.

It is proposed to utilize drones of bumblebees to pollinate red clover and alfalfa. Drones may be obtained in large numbers from bumblebee species which produce large colonies (1500-1600 individuals 'to1ith 1!. terrestris) by rearing and maintaining these colonies under complete control in a rearing room with temperatures around 30°C. Since drones are larger and of more uniform size than workers, even medium tongued species are adapted to obtain nectar and pollinate red clover. Drones do not re­quire hives and therefore attract no natural enemies. Drones lack a sting and are welcomed by the personnel in charge of the practical breeding work as stingless pollinat~. By utilizing and exposing only drones to the risk$ of open field conditions, the workers may be retained in the nest in order to care for the brood and increase the colony.

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Bumblebee drones are perfectly adapted to conditions in green­houses and field cages because they do not need sun or blue sky for orientation and shortly learn to avoid the glass and screen confining a limited flight range as is the case in greenhouse compartments or cages.

These encouraging results obtained Hith drones of European bumblebee species suggest similar research to be initiated on the effectivity in pollination achieved by drones of American species for which comparative observations are lacking.

6. Acknowledgements .

The new type of nest box Has constructed by E. Hyss. Bumble­bee colonies Here maintained by Mrs. A. Kundig and Miss A. Binggeli. The inspection of seed set Has conducted by Miss A. Binggeli at the former Swiss Federal Experiment Station for Agriculture, 8050 Zuerich-Oer1ikon, SHitzer1and. Red clover plantings and pollina­tion cages "ere provided by B. Nuesch, plant breeder nOw at the Swiss Federal Research Station for Agronomy, 8046 Zuerich­Reckenho1z. I herewith express my gratitude for the accurate and dependable services and good cooperation I enjoyed.

7. References.

Hasse1rot, T. B. bee colonies. Agron.

(1952). J., 44,

A new method for starting bumb1e-218-19.

Horber, E. Vierte1jschrft .

(1961). Beitrag zur Domestikation der Humme1n. Naturf. Ges . Zurich 106, 425-447.

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Table 1. Seed set in red clover when subjected to various species of bumblebees.

---No. of %

flowers seed Species Sex Year Inspected set

A· asrorum 1965 . ,3,961 67.53

!. hvpnorum colony 1961 4,965 51.4

c7' 1963 6,849 72.1

J' 1963 5,974 61.8

cl' 1963 2,426 34.8

r:?1 1963 6,934 73.3

~ 1!. 1apidarius colony 1961 4,628 70.67

rfl 1967 2,925 74.0

!. si1vuum colony 1963 14,460 79.9

1! .. 1ucorum 0 1963 12,617 59.3

0 1963 9,771 35.1

0 1963 12,426 63.1

0 1963 11,551 66.9

0 1964 4,832 53.8

0 1964 4,953 45.2

0 1964 4,600 56.1

0 1964 4,533 60.4

0 1966 20,225 21.6

~ 0 1966 13,320 19.1

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Table 1 (concluded).

No.of % flowers seed

Species Sex Year ins:eected set

j!. terrestris 0 1964 4,765 33.52

0 1964 4,826 46.7

0 1964 6,103 40.9

0 1964 5,953 21.5

0 1964 5,908 81.4

0 1964 ~,Z4~ 80.4 - - - - - - ., - --_ .. _-!. terrestris 0 1966 17,941 17.8

0 1966 26,931 7.2

0 1966 24,026 15.9 - - - - - - - - - --- -~ 0 1966 26,199 41.9

0 1967 2,876 62

0 1967 2,988 18

0 1967 3,299 80

0 1967 3,015 86

0 1967 2,786 16

0 1969 12,522 71.4

0 1969!1 1,232 19.2!1 Pollinators unknown Oerlikon field ? 1961 4,488 65.3 Oerlikon field ? 1961 5,762 71.9 Braunwa1d ? 1962 1,858 30.2 Braunwald ? 1962 2,243 53.7 Reckenholz ? 1965 5,982 72.3 Reckenho1z ? 1965.!1 6,619 69.';'1 Reckenho1z ? 196511 6,739 21.7!1

11 - Seed set was dete~ined on samples of diploid red clover varieties

~ with the exception of the years 1965 and 1969 respectively where - we obtained samples of tetraploid red clover from Reckenholz.

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AUAUA SEED PRODUCTION PROBLEMS IN CALIFORNIA

1. J •. JOHNSON Cal/t'1est Seeds

Woodland, California

(Abstract)

During the past ten years, alfalfa seed production in California has undergone major changes, coincident with the expansion of seed production for proprietary varieties. The majority of alfalfa seed now grown is under contract produc­tion with the company owning the variety or for produc1as seed of varieties either for export or for other firms in the USA. The acreage in alfalfa seed production also has decreased from the high levels of 140,000 acres in the late Fifties and early Sixties to approximately 10QPOO acres at the present date. Prices paid to seed growers for proprietary varieties and con­tracted production generally are determined in advance of pro­duction. Prices paid to seed growers of public varieties are still largely dete~ined by prevailing prices for that variety. Seed production of proprietary varieties has resulted in a stability in prices paid to growers--a feature lacking a decade or more ago.

Alfalfa seed production in California still has many prob­lems that have not been solved. These include:

1. Competitive position of alfalfa with other crops for use of irrigation water and for management inputs.

This factor varies in importance in different parts of California. High cost of water from the new California Agua­duct in the San Joaquin Valley may pose greater l~itations on its use for alfalfa than on higher (and more stable) income crops such as cotton, melons, tomatoes, etc.

2. Competitive position of alfalfa with other crops for finan­cing through lending agencies. The higher risks in alfalfa seed production become an important factor in availability of produc­tion credit.

3. Problems in control of destructive insect pests. Such prob­lems include the present and possible restrictions in use of insecticides that have been effectively used, the damages to pol­linators through control of insects in adjacent crops and to such new and damaging insects as the stink bug.

It often bas been concluded that California alfalfa seed growers have learned how to overcome most of the production prob­lems except that of effective pollination. Important gains that benefit seed production are constatly being made. These factors include:

1. Development of new alfalfa varieties that have genetic po­tentials for high seed yield.

2. Development of new alfalfa varieties with resistance to those diseases and insects that limit seed yields or add to seed production costs for their control, even though such characters may be unimportant in the area of seed usage.

3. Development of a better understanding on pollination prob­lems, including the extensive work (with financial support from the industry) to develop the hybrid queen honeybee with prefer­ence for alfalfa pollen and with greater reproductive capacity.

Although alfalfa seed producers are constantly faced with new and sometimes difficult problems to solve, the combined knowledge of the grower and of the field services staff of the seed companies with whom they deal have heretofore successfully met these challenges. I am sure they can also do so in the future.

Alfalfa Seed Production in the Pacific Northwest­Potentials and Problems

R. R. Kalton and D. E. Brown Felco - Land O'Lakes, Inc.

The Pacific Northwest states of Washington, Oregon, and Idaho represent one of the key regions of "specialized" alfalfa seed production in North America. In recent years alfalfa seed has been a significant cash crop in each of these states. Whether or not seed production continues of importance in this area depends in part on the future of alfalfa usage country-wide and on the capacity to solve economic, agronomic, and other problems associated with seed production there.

In discussing potentials and problems for alfalfa seed pro­duction in the PNW, it seems desirable at first to outline briefly the nature of the area and historical trends in acreage and production. Advantages and disadvantages of the area for this purpose also are pertinent factors to the topic. Produc­tion problems will be discussed next in more detail with the final section devoted to potentials for the future.

Nature of the PNW Area

The bulk of alfalfa seed production in the PNW is found in semi-arid to arid regions of 10-12 inches of rain or less. Most of the seed fields are irrigated. Other climatic and environ-

27

mental factors, however, vary considerably from location to location due to widely varying soils, topography, and altitudes. Seed production is concentrated primarily in the following areas:

Columbia Basin - Washington Yakima Valley - Washington Walla Walla area - Washington, Oregon Lower Snake River area - Idaho Upper Snake River area - Idaho Ma1heur County - Oregon

It is obvious that this region represents considerable environmental diversity for alfalfa seed production!

Production and Acreage Trends

To obtain a picture of alfalfa production in the PNW, acreages, yields/acre and production in relation to California and the U.S. for the period from 1948 to 1970 are presented in Table 1. Compared with the 1948-57 period, trends have been up substantially for acres, yields/acre and total production in Washington, Oregon, and Idaho. Notably, Washington and Oregon have had higher yields/acre than California for some time. Idaho was higher in 1970 also but usually bas its yield average lowered by poor production conditions in eastern areas of the state in many years.

In relation to the U.S. total, these three states have been producins from 1/4 to 1/3 of the seed crop in recent years. If one considers only the hardy types, the proportion would be even larger. Interestingly, acreages for alfalfa seed the last few years have held at a proportionately higher level than in Cali­fornia, compared with the 1950's and the early 1960's.

I dontt know the percentage of the acreage or production which qualifies as certified in the PNW, but it is well over 50%, I'm sure.

Alfalfa Seed Production Advantages in the PNW

In general, the PNW has several advantages which make alfalfa seed production attractive to seed growers and the seed industry. Briefly, these are:

Good water supplies - reasonable costs, most areas. Generally favorable summer and fall weather - dry. Reasonably land values - most areas. Two good pollinators - alkali and leaf cutter bees. Winter freezes - not too severe most areas, but enough

,

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Table 1. Alfalfa Seed Production in the Pacific Northwest fram 1948 to 1970.11

1948-57 1958-62 1963-67 1968 1969 1970 Ave. Ave. Ave. (Prelim. )

Acreage

Idaho 31,500 38,000 42,600 39,000 38,000 39,000 Washington 20,200 22,400 27,000 24,000 26,000 30,000 Oregon 6,900 12,400 18,600 13,500 13,000 12,500 California 115,400 142,000 104,400 103,000 96,000 105,000

Yields Eer acre (lbs.l

Idaho 157 333 320 310 375 450 Washington 462 453 484 500 525 645 Oregon 278 507 471 380 440 550 California 372 376 437 480 345 430 U.s. Total 139 189 202 211 210 221

("., Production (1,000,000 lbs.)

Idaho 5.0 12.7 13.0 12.1 14.2 17.6 Washington 10.1 10.2 12.8 12.0 13.6 19.3 Oregon 2.0 6.6 8.5 5.1 5.7 6.9 California 46.4 53.8 45.6 49.4 33.1 45.1 U.s. Total 142.0 131.9 130.7 115.8 103.5 140.9

70PNW of U. S • Total 12.0 22.4 26.2 25.2 32.4 31.1

1/ - Data from U.S.D.A., Statistical Reporting Service.

2~

to r educe insect and disease problems. Seasona l "eather means les s genetic shift potential in

hardy varieties . Well distributed modern processing facilities . Experienced gro"er s . Profitable seed yi eld potentials with good management. Isolation probl ems not too great - topography. LnHer 'Hater r equ irement than Southe rn areas . Alfa lfa seed production - fits "ell into rotation

patterns with bee t s , potatoes, mint, corn, etc .

Disadvantages of PNH for Al fa lfa Seed Production

There a l so a r e some disadvantages in the PNH, "hich include:

Many smal l fields - due t o topography - higher costs/unit. Alfalfa seed production must compet e with high value crop s

such as potatoes, s ugar beets, onions, mint, etc. which means lo"er priority in attention .

Many growers combine seed and hay operations - gives lower seed yield and requires high planting rates.

Can have late spring and early fall frosts and fall rains in some years.

Alkali bees - dep l e t ed by insect control practices and depredations' by man.

Current Production Problems

Several long- time alfal fa seed plant managers were contacted regarding major production problems currently facing the alfalfa seed grower. All were in agreement that the cost-price squeeze was a very s ignificant problem. In the last few year s essentially all production costs - land, labor, machinery, irrigation , interest, etc. have gone up and up ,·,hile prices received have held quite constant. Total costs to grow an acre of alfalfa seed now run from $175 - $200/acre up to $250 /acre or more under irrigation. This means growers mus t produce about 450 lbs./acre of clean seed at 40C/lb. to break even at the lower cost l eve l and over 600 lbs. per at the higher l evel .

Major cos t items are interest on the land, machinery, insect and weed control, pollination (bees) and irrigation. And, little can be done, managementwise, to reduce these costs or the l esser one such as combining , es t ab li shment, taxes, cultivation, defolia­tion. So, grower s look for the best prices on seed contracts and the best seed yi e l ding var i etie s where possible.

A second major problem i s the one of good pollination. For­tunately, leaf cutter bees properly managed have been very help­ful. Alkali bee s also do well in some areas when carefully cul-

30

tured. However, insect control practices are necessary also, and integrating insect control with bee management is difficult to say the least.

Weed control is a serious problem in many areas also. Con­trol of volunteers falls in the same category. Here again, timely use of proper cultivation and chemicals combined with good seed cleaning facilities helps keep the problem at a minimum level.

With the growing restrictions on chemical usage and burning, many alfalfa seed people are fearful that insect, disease, and weed control problems will become more difficult in the future. Time will tell what will happen in this area.

The growing number of varieties also presents problems in isolation, contract arrangements, pricing, and processing logis­tics. Often, little is kno~m about seed production capabilities of many of these new varieties. And, results from California do not necessarily apply in the PNW. Varieties differ in insect (aphid) and disease (wilt, nematode) re~istance too, which can affect costs of production. Since certification requires 3 years out of alfalfa to plant to a new variety, the result is often to keep the old stands in as long as possible.

Other crops such as sugar beets, potatoes, mint, onions, hops, etc. have gross return potentials from $500 - $l,OOO/acre or more. Thus, they receive priority on land, care, irrigation, etc. Often, this means growing alfalfa seed on the poorer land with the min~um attention which typically results in lower seed yields.

Shifting to New Varieties

Handicaps to production of the newer varieties decidedly exist, as already mentioned. Isolation problems, lack of knowledge on seed, insect, and disease traits, and years out (of alfalfa) all work against changing over to new varieties and promote persistence of older varieties. However, growers will change if substantial price premiums are offered. This seems to be a must even though a new variety may be an excellent seeder. Thus, new varieties have to sell for more for some time on the user end. This is different than the pricing story on annual seed crops.

Potentials for the Future

The future of alfalfa seed production in the PNW depends above all on the future use of alfalfa seed. Up to a point, the PNW can remain competitive in seed production. However, for seed production levels to be maintained at somewhere near today's struc­ture, either growers prices must go up or more efficient pro­duction (higher yields) per acre must be obtained.

31

Among the promising factors which can help the production situation are:

Area integrated insect control. Better knowledge and attention to seed producing

ability of varieties or hybrids. Better fertilization and irrigation practices. Improved leaf cutter and alkali bee management. Reduce the number of new varieties introduced. More alfalfa seed production specialists (~ow culture)

and fewer growers of alfalfa seed. Good systemic chemical for insect control up to 90

days or so. Broad spectru~ single herbicide effective for 90-120 days. Better understanding of internal chemistry of plant

and seed set. Varieties with more insect and disease resistance. Foliar feeding may help seed set.

Significant progress on one or several of these points could help considerably in improving the profitability of alfalfa seed production in the PNW. A formula for consistent yields at the 700 - 800 lbs./acre yield level or better would do much to main­tain a good cash crop position for alfalfa seed in this region.

1971 Report to Central Alfalfa Improvement Conference

W. H. Skrdla North Central Regional Plant Introduction Station

Ames, Iowa

Since this is a dual-purpose report, for both the NCR-36 Technical Committee and the Central Alfalfa Improvement Con­ference, it will include alfalfa as well as other forage crops.

1. Increasing original seed of alfalfa introductions through controlled pollination. At the 1970 meeting of the National Al­falfa Improvement Conference, a proposal was presented and ac­cepted that would help preserve the genotypes of original seed of alfalfa introductions. Presently, open pollinated increases are made at the Regional Station from original seed and when the supply is exhausted or the original seed becomes non-viable, we must turn to the open pollinated seed as a'·aource of planting stock for making future seed increases. The basis of the proM posal is to request assistance from alfalfa breeders whereby each person cooperating would increase original seed of from one to several introductions. Plants within each introduction would be intermated to obtain controlled pollination. Only two to ten

32

thousand seeds would be required and would be utilized as follows:

(1) For permanent preservation at the National Seed Storage Laboratory.

(2) For use by the North Central Regional Plant Introduction Station as a source of planting stock for making open­pollinated increases.

(3) For conducting special research.

Alfalfa seed orders would be filled using the o.P. seed grown from either original seed or from seed produced by con­trolled pollination.

2. Code for a uniform data recording and retrieval system for alfalfa.

The National Alfalfa Improvement Conference also accepted, in 1970, a code for a uniform data recording and retrieval system for use in evaluating alfalfa. It is an open ended system and includes codes for plant characteristics, diseases and nema­todes, insects and data comments.

3. Disease work on forage crops, planned or underway, at the Regional Station, R. L. Clark.

4. Leptosphaerulina on alfalfa.

Little work was done on alfalfa during the past year. During the summer of 1970, 16 Medicago introductions were evaluated for Leposphaerulina reaction. Lines 314580 and 325398 appeared to have some resistance, rating 2.8 and 2.6, respectively on a 0-5 scale, where 5 is severe disease. Gr~ rated 3.6, Ladak 3.3, Ranger 3.0, and Vernal 3.6 in the same test.

The test was carried out in the laboratory using high out­put grolux lights at 700-1000 foot-candles for 12 hours each day. Young leaves (5 per plant) were collected from plants growing in the field and floated on distilled water in petri dishes. A piece of 1. briosiana culture was placed on the in­side of the lid directly over each leaf. Readings were taken one week after inoculation. Temperatures during the week were o 0 at a constant 78 F. (26 C.).

b. Ergot sclerotia.

During the past year, work was started on determining longe­vity of ergot sclerotia under our seed storage conditions. The

1"""\, --

33

latest data, taken February 25, 1971, indicate that survival may be as long as 13 years in Dactylis. This is a disturbing finding. It was hoped that s~lerotia would die in only a few years.

Since ergot is such a problem in many of our grasses, we will try some cultural control methods (sanitation, isolation) in succeeding years. Chemical control methods are being studied at Oregon State and if any good ones are found, we will try to in­corporate them into our program.

c. Scorpiurus bacterial disease.

The undescribed bacterium on Scorpiurus is still undescribed. We hope to have elctron micrographs of it later this month and, with help from Dr. R. N. Goodman at Columbia, identification at least to genus. It grows poorly in culture making it difficult to work with.

4. Evaluation of Medicago spp. for reaction to potato leaf­hopper at the Regional Station, J. L. Jarvis.

A number of perennial species of Medicago are of interest as potential sources of resistance to the alfalfa weevil. Species, other than M. sativa and M. falcata, have not been evaluated for resistance to potato leafhopper. It is important to know if these Medicago spp. are susceptible to leafhoppers; if these species should prove to be sources of resistance to alfalfa weevil, care should be taken not to also transfer susceptibility to leaf­hoppers.

Plans are to begin field work in 1971 toward evaluating perennial Medicago spp., other than!:!. sativa and!1. falcata, for leafhopper resistance.

5. Alaska native grass collection. Over a period of years, the Alaska Station has been engaged in collecting native grasses, pri­marily Festuca, Poa, Bromus, and Agropyron for their forage improvement work. For a three year period ending June 30, 1969, assistance was provided by the USDA New Crops Research Branch, through NC-7, for this collecting work. PI numbers were assigned to a portion of this collection and a list of seed available was prepared and distributed. Numbers were assigned to 36 Festuca rubra ascessions, 23 of which are available. Numbers were also assigned to 134 f2! pratensis accessions, 87 of which are avail­able. The Alaska Station is assisting with seed increases. Grass breeders are encouraged to take a look at this native Alaskan material.

6. Plant exploration trip to South Africa. A plant exploration

34

trip to S~uth Africa is being conducted by Dr. A. J. Oakes of the USDA New Crops Research Branch. This is the second phase of a trip he made in 1964. From that trip, many items collected are developing into promising forage crops for the southern states. Ma~Digitarias are showing up well.

Dr. Oakes will be in South Africa between February and April, 1971. Priority will be given to collecting warm season grasses • . Secondary attention will be toward collecting browse and soil stabilization species.

7. South Dakota native grass exploration. Through sponsorship of NC-7 and assistance from the USDA New Crops Research Branch, Dr. Jim Ross at South Dakota is making a collection of native grass species. The work started July 1, 1969, and will continue for three years. Over 300 collections were made between July 1, 1969, and June 30, 1970. The material is lined out in a nursery for establishment and evaluation.

8. Increase of Lotus corniculatus, PI 251146. At Missouri, Dr. J. D. Baldridge screened all Lotus corniculatus introductions for resistance to root and crown rot. He found two from Yugo­slavia, PI's 251146 and 251147, that were superior to commercial check cultivars in persistence and resistance to root rot and other environmental stresses at Columbia, Missouri. In addition, PI 251146 showed exceptional seed production under these poor growing conditions. Through assistance from NC-83, seven pounds of seed of this accession were produced in 1970 for Baldridge for further large scale testing.

9. Hail damage at Regional Station to 1969 alfalfa seed increase. On September 6, 1969, a severe wind and hailstorm damaged our seed increase plots. Small but numerous hailstones driven by a 90 mph wind badly damaged all crops. Seed that had natural pro­tection by flesh and husks (tomatoes, pumpkins, cucumbers, corn, etc.) could be salvaged. Unharvested seed having less protection like most forage crops was lost entirely. Most of the alfalfa seed was still in the field at the time of the storm. We lost it all because the plants were badly broken, much seed was knocked out of the pods and many pods were completely broken off the plants. Wind and water carried the loose seed from one row to another and created a contamination problem.

We cut and removed all the plant material but later found that seedlings began to emerge from within the crown ~rea. After much deliberation that following winter, we decided to undercut the accessions which we couldn't afford to lose, remove the soil and transplant the crowns. By shaking the soil from the crowns, we had hoped to eliminate most or all stray seed. The transplan­tation turned out to be generally successful and only a few plants

35

were lost. We observed no seedlings to emerge in the transplanted material.

Slides were presented to show damage, t_ansplanting techni­que and the results.

REPORT ON NCR-36

K. H. Asay University of Missouri - Columbia

(Presented by D. K. Barnes)

NCR-36 met on March 2, 1971. Reports were presented by representatives of each state and the various agencies in atten­dance.

A major portion of the meeting was devoted to a discussion of the application of "systems analysis" in forage breeding. Each representative discussed and presented data regarding a preassigned topic related to systems analysis ie. variety syn­theSiS, progeny evaluation, selection criteria etc. A sub com­mittee will meet prior to the next regular meeting of NCR-36 to further consider this topic. The committee plans to eventually summarize these deliberations in a publication.

Dr. I. T. Carlson will serve as chairman of NCR-36 this year.

Report on NC-83 Seed Production of Breeding Lines of Insect-Pollinated Legumes

E. L. Sorensen Plant Science Research Division, ARS, USDA

Manhattan, Kansas

During 1966, replicated tests of 30 alfalfa clones were established in six North Central states (Indiana, Iowa, Kansas, Minnesota, Nebraska and South Dakota) and in California and Idaho to determine whether associations between seed production potential and morphological and/or physiological plant charac­teristics exist. Measurements were obtained on 18 morphological and physiological traits. A preliminary report of the study is contained in the eleventh report of this conference. The study was completed last year and a portion of the data are summarized in an NC-83 Technical Committee Regional Bulletin entitled "Predicting Seed Yields of Alfalfa Clones." A manu­script is being prepared to present parent-progeny relationships.

A study similar to the alfalfa 30-clone study was initiated

36

with Birdsfoot trefoil in 1969. Character measurements included flowers per umbel, umbels per stem, stems per plant, pods per umbel, seeds per pod, pod length, flowering date, maturity date, vigor rating, and growth type, plus other pertinent information. The best character for predicting seed yield in the first year in Oregon or North Dakota was pods per umbel. There appeared to be little relationship between first-year seed yield in Minnesota and any of the plant characters measured in Iowa or Illinois.

An o.P. progeny seed yield trial will be established in Minnesota and North Dakota and O.P. progeny forage yield trials will be established in Illinois, Iowa and Minnesota during 1971.

At our last conference, W. R. Kehr reported on natural cross­ing in alfalfa in relation to genetic markers and planting methods. Also; at the 22nd Alfalfa Improvement Conference last summer, he discussed the use of incompatibilities in hybrid production.

A new study to obtain additional information on the percent of crossing in alfalfa was initiated in 1970. The methods of planting are: Alternate plants and alternate rows of purple-and yellow-flowered plants, and direct seeded mixtures of one part purple to two parts yellow flowered plants and one part purple to one part yellow-flowered plants. Caged and open-polli­nated plantings were pollinated with honeybees in California and leafcutter bees in Idaho.

Report on the National Certified Alfalfa Variety Review Board

C. H. Hanson Research Leader, Alfalfa Investigation's

United States Department of Agriculture Plant Science Research Division

Beltsville, Maryland 20705

The National Certified Alfalfa Variety Review Board met in Chicago on December 8, 1970, and issued favorable reports on eight varieties. The varieties and applicants are given below.

Hayden - Arizona Agricultural Experiment Station Sonora-70 - Arizona Agricultural Experiment Station Thor - Northrup, King & Co. Warrior - Northrup, King & Co.

Weevlchek - Farmers Forage Research Cooperative WL 504 - Waterman-Loomis Cbmpany WL 508 - Waterman-Locmis Company 183 - DeKalb Agresearch

37

Copies of the report of the Board were mailed to interested persons. If I overlooked anyone, please let me know.

The Board is expected to meet again in December 1971.

CONCLUDING BUSINESS

Dr. C. H. Hanson announced that the 1972 national Alfalfa Improvement Conference will meet at Ottawa, Ontario, Canada, July 10-12. The host institution will be Ottawa Research Sta­tion. The new chairman is Dr. D. H. Heinrichs, Head, Plant Science Section, Research Station, Canada Department of Agri­culture, Swift Current, Sask, Canada. Dr. Heinrichs is in the process of developing plans for the Conference. If you have suggestions, please submit them to the Central Alfalfa Con­ference chairman.

Chairman Sorensen sent the follwoing letter of appreciation to Barbara Nettle, The St. Louis Gateway Hotel, Washington Avenue at Ninth Street, St. Louis, Missouri 63101.

"The members of the Central Alfalfa Improvement Conference wish to express our appreciation to the management and staff of the St. Louis Gateway Hotel for the excellent facilities and accomodation~ which we enjoyed at our 12th meeting held March 3 and 4, 1971. We were especially impressed with the ready avail­ability of the staff and their ~ediate response to our needs. Assistance with visual aids, equipment, seating arrangements etc. contributed to the success of our meetings. We express thanks to you for arranging for meeting rooms and accomodations."

Our next meeting will be under the direction of our new chairman Dr. M. D. Rumbaugh, Plant Science Deparenent, South D&tota State University, Brookings, South Dakota, 57006. Dr. Rumbaugh requested that suggestions for the date and place of the thirteenth Central Alfalfa Improvement Conference to be held during 1973 be sent to htm. Topics of potential interest to par­ticipants and other program suggestions should also be sent to Rumbaugh.

The joint sessioThof the conference adjourned at 5:20 P.M., March 3, 1971.

A,

38

NEW CAlC CHECK VARIETIES

The Twelfth Central Alfalfa Improvement Conference adopted a new set of forage yield check varieties on March 4, 1971 for state and regional variety trials. The new CAlC check varieties are: Dawson, Kanza, Saranac and Vernal.

Current plans are to continue use of the present seed stocks of Dawson (D C C 67) and Vernal (V C C 63) in 1971. New composites of Dawson, Vernal, Saranac and Kanza will be prepared from seed lots obtained from the 1971 seed crop from a number of sources for each variety. The new check lots will be available from Dr. Kehr in the spring of 1972.

INSECT AND DISEASE RESISTANT CHECKS

Members of the twelfth CAlC also adopted the following re­sistant and susceptible checks for disease and insect resis­tance at the March 4, 1971 session.

Insect Resistant check(s)

Potato leafhopper l'leevlchek and/or MSACV13An3

Spotted aphid Dawson and/or Kanza

Pea aphid Dawson and/or Kanza

Alfalfa weevil Team and/or Weev1chek

Disease Resistant

Bacterial 'tolilt

Anthracnose

Phytophthora

Connnon Leaf Spot

Rust

Yellow Leaf Blotch

Downey ~ldel-1

check

Vernal

~fSACW3An3

MnPA

"MSACW3An3

MSACW3An3

Teton

Saranac

Susceptible check(s)

Ranger

Ranger

Ranger

Ranger and/or Vernal

Susceptible check(s)

DuPuits and/or Narragansett

Dawson and/or Saranac

Saranac

Ranger

Saranac and/or Ranger

Ranger

Ranger

",

39

COMPOSITION OF CHECK LOTS OF PREVIOUS CAlC CHECK VARIETIES

Dr. Kehr suggested that it would be appropriate to in­clude a description of the composition of check lots of the former CAlC check varieties, since this information was never included in the minutes of a previous meeting.

Seed lots of Atlantic, Buffalo, Rauger, Narragansett and Vernal for local and regional yield tests were accumulated at Lincoln through the cooperation of C. H. Hanson, state certification agencies and seedsmen and bulked as requested at the 8th Central Alfalfa Improvement Conference. Seed of Ranger, Narragansett and Vernal ~7ac used in Eastern Conference tests too. A three-year supp~y was obtained based on previous usage.

A brief description of these lots follows.

Atlantic ACC63

California Idaho Wyoming

Buffalo BCC63

California Kansas Oklahoma Utah

92% germination

35 lbs. 3 lots bulked 35 lbs. 1 lot bulked 35 lbs. 1 lot bulked

105

82% germination

20 Ibs. 20 Ibs. 20 lbs. 20 lbs. 80

2 lots bulked 2 lots bulked 6 lots bulked 7 lots bulked

Narragansett~NCC63 92% germination

Idaho 20 lbs. 12 lots bulked Oregon 20 lbs. 7 lots bulked Utah 20 Ibs. I lot bulked Washington 20 1bs. 1 lot bulked

80

Ranger RCC63

California Idaho Nebraska Oregon Washington

90% germination

20 lbs. 20 Ibs. 20 1bs. 20 lbs. 20 lbs.

100

7 lots bulked 4 lots bulked I lot bulked 5 lots bulked 2 lots bulked

. ,

Vernal VCC63

California Idaho Oregon South Dakota Washington

.40

96% germination

20· lbs. 20 lbs. 20 1bs. 20 1bs. 20 lbs.

100

2 lots bulked 10 lots bulked 13 lots bulked

1 lot bulked 9 lots bulked

Dawson DCC 67 - This l·ms composed of three certified seed lots, the first available in 1967. One-third was obtained from Calapproved Seed Company of California, one-third fram the Arnold-Thomas Seed Company in California, and one-third fram a seedsman in Idaho •

.. ,

Raymond Altevogt

K. H. Asa,

J. D. Axtell

D. K. Barnes

F. L. Barnett

D. F. Beard

E. H. Beyer

E. T. Bingham

R..J. Buker

I. T. Carlson

R. L. Clark

P. 1. Frosheiser

H. J. Gorz

D. W. Graffis

C. H. Hanson

Ern8t Horber

A. W.Hovin

S. J. Johnson

R. R. ICalton

w. R. Kehr

K. L. Larson

41

Joint Session Central Alfalfa Improvement Conference

March'3, 1971

REGISTER

9742 Lookout Drive

University of Missouri

Purdue University

University of Minn., USDA

Kansas State University

Waterman-Loomis Company

Farm Seed Research Corp.

University of Wisconsin

Farmers Forage Research

Iowa State University

Regional Plant Intro. Sta.

University of Minn., USDA

University of Neb., USDA

University of Illinois

CRD, ARB, USDA

Kansas State University

University of Minnesota

Caladino/west Seed

Felco/Land O'Lakes

University of Neb., ARS

University of Missouri

St. Louis, Missouri

Columbia, Missouri

Lafayette, Indiana

St. Paul, Minnesota

Manhattan, Kansas

Adelphi, Maryland

San Juan Bautista, Calif.

Madison, Wisconsin

West Lafayette, Indiana

Ames, Iowa

Ames, Iowa

St. Paul, Minnesota

Lincoln, Nebraska

Urbana, Illinois

Beltsville, Maryland

Manhattan, Kansas

St. Paul, Minnesota

Woodland, California

Fort Dodge, Iowa·

Lincoln, Nebraska

Coluinbia, Missouri

D. W. Meyer

D. A. Miller

J. W. Miller

M. K. Miller

J. L • .Mings

R. H. Ogden

R. H. llitter

M. D. Rumbaugh

P. C. Sandal

George Semeniuk

A. B. Simons

w. U. Skrdla

E. L. Sorensen

D. L. Stuteville

Paul Sun

c. M. Taliaferro

M. B. Tesar

J. R. Thomas ., P. W. VanKeuren

North Dakota State UDiv. Fargo~ N. Dakota

University of Illinois Urbana, Illinois

A~no1d Thomas Seed Servo Johnston, Iowa

Arnold Thomas Seed Servo Fresno, California

Northrup King and Company Washington, Iowa

Univ. of Neb. (East Campus) Lincoln, Nebraska

L. T eweles Seed Company Bradsfield, Wisconsin

South Dakota State Univ. Brooking, South Dakota

North Dakota State Univ. Fargo, North Dakota

South Dakota State Univ. Brooking, South Dakota

Dekalb Ag. Research & Cal/west Dekalb, Indiana

N. C. Regional Plant Int. Sta. Ames, Iowa

Kansas State Univ., ARS

Kansas State University

L. T· eweles Seed Company

Oklahoma State University

Michigan State University

Rudy Patrick Company

Ohio Ag. Research & Development Center

Manhattan, Kansas

Manhattan, Kansas

Clinton, .Wisconsin

Stillwater, Oklahoma

East Lansing, Michigan

Ames, Iowa

Wooster, Ohio