Florida MDR 98 Peanut 1

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2 S-401 Florida MDR 98 Peanut 1 D. W. Gorbet and F. M. Shokes 2 Florida MDR 98 is a new runner, market-type peanut cultivar (Arachis hypogaea hypogaea L.) released by the University of Florida Agricultural Experiment Station. MDR stands for disease resistance. This cultivar has good resistance to late leafspot, stem rot/white mold, rust and tomato spotted wilt virus (TSWV), which is essentially the same disease resistance package as Southern Runner, only better. MDR 98 has excellent yield potential, grade, and oil chemistry and should allow growers to lower fungicide inputs and reduce the risk of loss to disease, without compromising yield or quality (5). Origin Florida MDR 98 originates from a cross made in 1984 between Southern Runner (SR) and an F plant, which was from a cross of Andru 93 and UF UF81206 has better late leafspot, white mold, and rust resistance than SR, with some resistance to the peanut root knot nematode, but the latter is hard to shell and grades poorly. The cross incorporates some of the earliness and seedling vigor of Andru 93, in addition to disease resistance. A pedigree selection program was followed in the F-F generation under unsprayed conditions (no leafspot control), and yield testing began in the F generation. Florida MDR 98 was initially tested as 84x b3-B or UF UF91108 was first yield tested in 1990 in unsprayed conditions at Marianna and was entered in sprayed tests in Marianna and Gainesville, Florida, in UF91108 was tested in the Uniform Peanut Performance Test (UPPT) in all major peanut producing states in UF91108 was tested in sprayed and unsprayed tests at multiple locations in Florida before its release in 1998 as Florida MDR 98 (5). Characteristics Florida MDR 98 has shown moderate to good resistance to late leafspot, white mold, and TSWV, with greater pod yields, larger seed size, and better grades than SR. MDR 98 has mid-oleic (65±%) fatty acid oil chemistry, as compared to about 50% oleic for Florunner (FR) and 80% for SunOleic 97R. Florida MDR 98 has about the same maturity and growth habit as SR, but its center stem is usually more prominent with larger leaflets. The plant foliage color is very similar to slightly darker green than for SR (5). 1. This document is S-401, one of a series of the Agronomy Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published April Please visit the EDIS Web site at 2. D. W. Gorbet, professor, Department of Agronomy, North Florida Research and Education Center-Marianna, IFAS, University of Florida and F. M. Shokes, former professor, Department of Plant Pathology, North Florida Research and Education Center-Marianna, IFAS, University of Florida, presently Center Director, Tidewater Agricultural Research and Extension Center, Suffolk, Virginia. The use of trade names in this publication is solely for the purpose of providing specific information. It is not a guarantee or warranty of the products named and does not signify that they are approved to the exclusion of others of suitable composition. The Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. For information on obtaining other extension publications, contact your county Cooperative Extension Service office. Florida Cooperative Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Christine Taylor Waddill, Dean.

3 Florida MDR 98 Peanut 2 Figure 1 shows a field of Foundation seed production being inverted in Plants show typical runner growth habit with runner market-type pods. Figure 2. Seed Source Figure 1. Yield and Quality The average pod yields, grades, and disease ratings for Florida MDR 98 in unsprayed field tests ( ) at Marianna, compared to SR and FR, are shown in Table 1. MDR 98 gave better yield, grade, and disease resistance than SR, with a 16% yield advantage. Yields and disease ratings of FR indicate the high disease pressure in these tests (5). Data from sprayed tests at Marianna and Gainesville are shown in Table 2 ( ). Florida MDR 98 showed a yield and grade advantage over FR, especially at Marianna. Ratings for TSWV were much lower for MDR 98 than for FR, indicating its level of resistance to this disease (5). Data from UPPT results in the southeast (Alabama, Florida, and Georgia) for indicate a 27% yield advantage of Florida MDR 98 (UF91108) over FR (1,2). Results from Marianna field studies that were inoculated with S. rolfsii (white mold) are shown in Table 3. MDR 98 had a 44% pod yield advantage over SR and a 224% advantage over FR, indicating that MDR 98 has better resistance to S. rolfsii than SR. Figure 2 shows a plot of MDR 98 compared to FR in the 1996 test, which shows the much greater disease present in FR (5). Florida MDR 98 is a protected variety (USDA Plant Variety Protection Certificate) and registered to be sold only as a class of certified seed. Seed inquiries should be made to Florida Foundation Seed Producers, Inc., P.O. Box 309, Greenwood, FL Acknowledgment The authors wish to express their appreciation to Florida peanut producers, the Florida Peanut Advisory Council and Florida Foundation Seed Producers, Inc. for financial support for this research. We also want to thank Dr. Harold Pattee (USDA-NCS), Mr. Walt Mozingo (VPI-Suffolk), Dr. Albert Culbreath and Dr. Jim Todd (UG-Tifton), UPPT cooperators (Dr. Bill Branch, Tifton, Ga. and Dr. Jim Bostick, Headland, AL), Dr. Ben Whitty and Dr. Sean O'Keefe (UF-Gainesville), Dr. P.C. Andersen and Ms. Kristen Hill (UF-Quincy NFREC), M&M Mars (Mr. Charles Ivy, Dr. Doug Manning, and Dr. L.J. Romanczyk), and Planters-LifeSavers (Dr. Doug Smyth). Special thanks go to Wayne Branch, Mike Bordelon, Charlie Riddle, Charles Bryant, Todd Mathews, Harry Wood, George Person, Mary Chambliss, Frank Harris and numerous other temporary helpers that provided dedicated technical support. References 1. Branch, W.D., J.P. Bostick, D.W. Gorbet, T.G. Isleib, J.S. Kirby, H.A. Peacock, C.E. Simpson, and O.D. Smith Uniform Peanut

4 Florida MDR 98 Peanut 3 Performance Tests UGA/CPES Res. Progress Rpt. No. 5-95, 21 pp. 2. Branch, W.D., J.P. Bostick, D.W. Gorbet, T.G. Isleib, J.S. Kirby, R.W. Mozingo, H.A. Peacock, C.E. Simpson, and O.D. Smith Uniform Peanut Performance Tests UGA/CPES Res. Progress Rpt. No. 4-96, 24 pp. 3. Culbreath, A.K., J.W. Todd, D.W. Gorbet, F.M. Shokes, and H.R. Pappu Field response of new peanut cultivar UF91108 to tomato spotted wilt virus. Plt. Dis. 81: Gorbet, Dan, Leonard Dunavin, Ben Whitty, Harry Wood, and Fred Shokes Florida peanut variety trials UF/IFAS, Marianna NFREC Res. Rpt pp. 5. Gorbet, D.W., F.M. Shokes, A.K. Culbreath, J.W. Todd, and E.B. Whitty Florida MDR 98 - A new multiple disease resistant peanut cultivar. UF/IFAS. Marianna NFREC Res. Rpt pp.

5 Florida MDR 98 Peanut 4 Table 1. Pod yield, grading, and disease data for Florida MDR 98 (from nineteen tests at Marianna, FL) that were not sprayed for leafspot control, Yield 100 seed Leaf spot disease Variety (lbs/a) %TSMK 1 %ELK 2 wt. (g) (1-10) 3 Fla. MDR Southern Runner Florunner TSMK = total sound mature kernels (ride 16/64 inch screen). 2 ELK = extra large kernels (ride 21.5/64 inch screen). 3 Disease rating 1-10, 1= no disease, 10 = all plants dead from leafspot.

6 Florida MDR 98 Peanut 5 Table 2. Pod yield, grading, and disease date for Florida MDR 98 from Marianna and Gainesville sprayed (leafspot) tests ( ). Yield 100 seed TSWV (1-10) Variety (lbs/a) %TSMK %ELK wt. (g) Disease 1 Marianna (6 tests) Fla. MDR Florunner Gainesville (3 tests) Fla. MDR Florunner TSWV = tomato spotted wilt virus, 1=no disease, 10 = 100% of plot severely infected.

7 Florida MDR 98 Peanut 6 Table 3. Pod yields and disease ratings for Florida MDR 98 in studies inoculated with S.rolfsii, causing white mold/stem rot at Marianna ( ). Yield (lbs/a) Disease (1-10) 1 Variety Avg Avg. Fla. MDR Southern Runner Florunner Disease rating 1-10, 1 = no disease, 10 = 100% infection and plants dying.

8 Florida MDR 98 Peanut 7 Table 4. Peanut cultivar test results at Marianna, Cultivar Pod yield (lbs/a) %TSMK TSWV (1-10) 1 Fla. MDR Georgia Green Southern Runner Andru Florunner Disease rating 1-10, 1 = no disease, 10 = 100% of plot severly infected.