Disas- Reisan Vaite fo S - 4 CONTENTS Page VARIETY DEVELOPMENT.........................................3 Origin ............................................ Disease Resistance .................................. Fruit Characteristics ................................. SUMMARY.......................................................7 AVAILABILITY OF SEED...........................................7 ACKNOWLEDGMENTS............................................8 LITERATURE CITED..............................................9 APPENDIX 4 4 5 ...................................................... 10 COVER PHOTO. Watermelon varieties developed at the Alabama Agricul- tural Experiment Station: AU-Producer, top, and AU-Jubilant, bottom. FIRST PRINTING 4M, JUNE 1985 Information contained herein is available to all persons without regardto race, color, sex, or national origin. AU-Jubilant &AU-Producer Quality, Disease-Resistant Watermelon Varieties for the South J.D. Norton, R.D. Cosper, D.A. Smith, and K.S. RymaI1 AU-JUBILANT AND AU-PRODUCER are new multiple disease-resistant watermelon varieties adapted to growing conditions in the Southeastern United States. They have resistance to anthracnose (Colletotrichum laginarium,race 2), Fusarium wilt (Fusariumoxysorium niveum), and gummy stem blight (Didymella bryoniae). Disease is a major factor limiting production of watermelon in Alabama. Anthracnose, Fusarium wilt, and gummy stem blight are three of the most serious diseases. Severe crop losses and reduced yields of melons have resulted from these diseases in certain fields in Alabama. Although the damage seems to be more widespread in the Gulf Coast area, there have been frequent reports of damage in central and north Alabama. Although satisfactory control of anthracnose and gummy stem blight may be accomplished with the proper application of organic fungicides during normal weather conditions, no control measure is effective during periods of high humidity and excessive rainfall. Furthermore, the three leading varieties, Charleston Gray, Jubilee, and Crimson Sweet, are not resistant to race 2 anthracnose or gummy stem blight (1,2,6). VARIETY. DEVELOPMENT The discovery that certain plant introductions (PI 189225 and P1 271778) were resistant to race 2 anthracnose (5) and gummy stem blight (3,4) led to the initiation of an Alabama Agricultural Experi- 'Respectively, Professor, Research Associate, Associate Professor, and Professor of Horticulture. ment Station watermelon breeding program to develop multiple disease-resistant breeding lines that produce high yields of excellent quality fruit. Two of these lines, AU-1 and AU-3, are currently being released as AU-Jubilant and AU-Producer, respectively, see cover illustration. Origin AU-Jubilant is an inbred line from the cross of Jubilee x P1271778, and AU-Producer is an inbred line from the cross of Crimson Sweet x PI 189225. Following the crosses, backcrossing and disease screening programs were followed with selection of disease-resistant seedlings that produced high yields of excellent quality fruit. Thus, AUJubilant and AU-Producer originated from programs of backcrossing and inbreeding to obtain resistance to race 2 anthracnose, Fusarium wilt, and gummy stem blight. These new varieties have been grown in trials at Auburn, the E. V. Smith Research Center, and four substations of the Alabama Agricultural Experiment Station, and in the Southern Cooperative Watermelon Variety Trials in other Southern States. Disease Resistance AU-Jubilant and AU-Producer have been rated for resistance to race 2 anthracnose, Fusarium wilt, and gummy stem blight in tests at locations in Alabama and other Southern States, table 1. ResisTABLE 1. DISEASE INDEX RATINGS FOR RESISTANCE TO ANTHRACNOSE, FUSARIUM WILT, AND GUMMY STEM BLIGHT Disease index' breeding line Cultivar orGummy Anthracnose race 2 2.5 2.1 5.0 5.0 Fusarium Gustem Averagemy wilt 3.0 1.0 3.0 3.0 blight 2.2 1.7 5.0 5.0 AU-Jubilant ......................... AU-Producer ........................ Charleston Gray ..................... Crimson Sweet ...................... 1.63 1.20 3.25 3.25 Jubilee ............................. 5.0 3.0 5.0 3.25 'Disease index: 0 = no injury to 5 = all plants severely injured. tance to race 2 anthracnose and gummy stem blight was incorporated into the breeding lines through screening programs which utilized an incubation chamber and greenhouse to eliminate susceptible plants from the populations (1,3,5,6). Multiple disease resistance of [4] AU-Jubilant and AU-Producer has been excellent in field plantings. Resistance to race 2 anthracnose and gummy stem blight was secured from PI 271778 and PI 189225 for AU-Jubilant and AU-Producer, respectively. Fruit Characteristics The fruit of AU-Jubilant are large and symmetrically elongate with uniform diameter for the length of the melon. Fruit are larger than Charleston Gray, Jubilee, and Crimson Sweet, table 2. Sizes are mostly in the 20- to 35-pound range, but weights of 40 pounds are not uncommon. The rind has a light green (138C 2) background with dark green (136B 2) stripes continuous for the length of the fruit. The rind is hard and tough and about 4/5 inch thick. The flesh is bright red (46C2) and firm, but not tough. Taste tests indicated that the edible quality of AU-Jubilant (color, texture, and taste) was higher than for Charleston Gray, Jubilee, and Crimson Sweet. Fruit of AU-Producer are round to oblong-round with few culls. Melons are larger than Crimson Sweet, table 2. Sizes are mostly in the 20- to 30-pound range, but weights of 35 pounds are not uncommon. The rind is smooth, hard, and tough, and about 3/4 inch thick. The rind color is light green (138B 2) with dark green stripes (136A 2). The flesh is dark red (46B2) and firm, but not tough. Fruit quality, as indicated by total soluble solids, was higher for AU-Producer than for the other varieties, table 2. Taste tests for edible quality (color, texture, and taste) were also higher for AU-Producer. Yield of fruit was highest for AU-Jubilant, table 2. Yield of fruit was higher for AU-Producer than for Crimson Sweet and Jubilee and comparable to Charleston Gray. Fruit weight was highest for AU-Jubilant. Fruit weight was greater for AU-Producer than for Crimson Sweet. Both AU-Jubilant and AU-Producer are homozygous and can be propagated by seed. Pollination is dependent primarily on honeybees. Should the native bee population be inadequate, additional bees will be required for normal-shaped fruit and high yields. 2 Colour Chart, The Royal Horticulture Society, London. [5] TABLE 2. YIELD AND FRUIT CHARACTERISTICS OF VARIETIES OF WATERMELON AT FIVE LOCATIONS IN ALABAMA, 1978-84 Cultivar or breeding line Yield! acre Lb. 42,455a 4 38,677b 36,477b 30,828c 30.429c Fruit weight Lb. 24.9a 20.3c 21.8b iS.Od 22.6b Soluble solids' Pct. 11.3b 11.8a 11.2cb i1lc 10.7d Quality preference 2 Width length ratio 0.43 .84 .44 .62 .43 Rind thickness In. 0.82 .75 .56 .86 1.00 Rind firmness 3 kg/cm 2 22.7 20.7 23.3 20.0 19.1 Days to maturity Rind color '~AU-Jubilant.................... AU-Producer................... Charleston Gray................. Crimson Sweet.................. jubilee........................ 2 Response 3 Puncture 4 8.0 8.1 7.5 7.9 7.6 85 77 80 80 90 Striped Striped Gray Striped Striped 'Total soluble solids determined with Bausch and Lomb refractometer, 0-25 percent scale. index: 9-10 = excellent, 7-8 = good, 5-6 = acceptable, and below 5 = unacceptable. test performed with Instron 1122 Instrument, 1-cm 2 Magnus Taylor probe. Puncture made at 5-cm intervals beginning at stem end. Mean separation within columns by Duncan's multiple range test, 5 percent level. SUMMARY AU-Jubilant and AU-Producer are superior to the current varieties of their type in yield, quality, and disease resistance. They are multiple disease resistant, with resistance to race 2 anthracnose, Fusarium wilt, and gummy stem blight. The varieties are being released to broaden the base of high quality melons available to growers in the Southern United States. Because of AU-Producer's early maturity, it fits well into the commercial production program to lengthen the shipping season for any given production area or grower. AVAILABILITY OF SEED Exclusive releases of AU-Jubilant and AU-Producer were made to Hollar and Company, Inc., Rocky Ford, Colorado 81067, for production and marketing of seed. Growers and home gardeners can find high quality seed at local wholesale and retail outlets. [7] ACKNOWLEDGMENTS The authors gratefully acknowledge the assistance of Grover B. Sowell, Jr., Research Pathologist, USDA Southeastern Regional Plant Introduction Station, Experiment, Georgia, for discovery of resistance to Didymella bryoniae and Colletotrichum laganarium,race 2, and for counseling in screening techniques with the disease organisms. Essential assistance was rendered by H. M. Bryce, E. V. Smith Research Center, Shorter, Alabama; and C. C. Carlton, J. A. Pitts, and K. C. Short, Chilton Area Horticulture Substation, Clanton, Alabama, in increasing seed for grower trials and conducting variety trials. Valuable assistance in conducting yield trials was rendered by M. H. Hollingsworth, North Alabama Horticulture Substation, Cullman, Alabama; E. L. Carden, F B. Selman, and R. L. McDaniel, Gulf Coast Substation, Fairhope, Alabama; and J. G. Starling and H. W. Ivey, Wiregrass Substation, Headland, Alabama. Assistance of growers in conducting production trials is deeply appreciated, as is the assistance of participants in the Southern Cooperative Watermelon Variety Trials. [8] LITERATURE CITED (1) NORTON, JOSEPH D. 1979. Inheritance of Resistance to Gummy Stem Blight in Watermelon. J. Amer. Soc. Hort. Sci. 14:630-632. , J. M. SNELL, H. M. BRYCE, C. C. CARLTON, AND M. (2) H. HOLLINGSWORTH. 1983. Breeding Watermelons for Disease Resistance. Ala. Agr. Exp. Sta. Highlights of Agr. Res. Vol. 30, No. 2. (3) SOWELL, G. B., JR. AND G. R. POINTER. 1962. Gummy Stem Blight Resistance of Introduced Watermelons. Plant Dis. Rptr. 46:883-885. .1975. An Additional Source of Resistance to Gummy Stem Blight in Watermelon. Plant Dis. Rptr. 59:413-415. , B. B. RHODES, AND J. D. NORTON. 1980. New Sources (5) of Resistance to Watermelon Anthracnose. J. Amer. Soc. Hort. Sci. 105:197-199. (6) SUVANPRAKORN, KAMOLVAN AND J. D. NORTON. 1980. Inheritance of Resistance to Race 2 Anthracnose in Watermelon. J. Amer. Soc. Hort. Sci. 105:862865. (4) [9] APPENDIX APPENDIX TABLE 1. AVERAGE YIELD PER ACRE OF WATERMELON CULTIVARS AND BREEDING LINES AT FIVE LOCATIONS IN ALABAMA, 1978-84 Yield, by location Cultivar or breeding line E.V. Smith Research Center Lb. 52,132a' 42,937b 39,983b 56,882a 54,814a Clanton Lb. 33,854b 23,196c 27,042c 38 ,13 9a 34,250b Cullman Lb. 36,900a 30,368a 29,630a 38 ,204 a 37,470a Fairhope Lb. 27,468b 38,389b 28,800b 38 ,939a 33,061ab Headland Average Lb. 29,489c 26,178c 27,320bc 38 ,339a 31,006b Lb. 36,467b 30,429c 30,828c 42,455a 38,677b Charleston Gray ... Jubilee ........... Crimson Sweet .... AU-Jubilant ....... AU-Producer ...... 'Mean separation within columns by Duncan's multiple range test, 5 percent level. APPENDIX TABLE 2. AVERAGE FRUIT WEIGHT OF WATERMELON CULTIVARS AND BREEDING LINES AT FIVE LOCATIONS IN ALABAMA, 1978-84 Average fruit weight, by location Cultivar or breeding line E.V. Smith Research Center Lb. 23.41c' 25.06b 19.64d 26.99a 22.55c Clanton Lb. 23.74b 22.94b 19.42c 25.76a 20.81bc Cullman Lb. 19.80c 21.60ab 17.42d 22.97a 20.29bc Fairhope Lb. 21.41b 22.64ab 17.12d 24.24a 18.62c Headland Average Lb. 19.97b 19.26bc 18.01d 23.76a 18.38c Lb. 21.79b 22.55b 21.79b 24.85a 20.28c Charleston Gray ... Jubilee ........... Crimson Sweet .... AU-Jubilant ....... AU-Producer ...... 'Mean separation within columns by Duncan's multiple range test, 5 percent level. APPENDIX TABLE 3. TOTAL SOLUBLE SOLIDS OF WATERMELON CULTIVARS AND BREEDING LINES AT FIVE LOCATIONS IN ALABAMA, 1978-84' Total soluble solids, by location Cultivar or breeding line E.V. Smith Research Center Clanton Lb. 10.98bc 10.65d 10.77cd 11.15b 11.49a Cullman Lb. 11.21b 10.85c 11.38ab 11.12bc 11.66a Fairhope Lb. 11.06b 10.58c 11.14b 11.26ab 11.63a Headland Average Lb. 11.23bc 10.39d 11.03c 11.35b 12.12a Lb. 11.17cb 10.66c 11.14c 11.31b 11.81a Lb. Charleston Gray ... 11.39b 2 Jubilee ........... .10.69c Crimson Sweet .... 11.40b AU-Jubilant ....... .11.65b AU-Producer ...... 12.18a 'Total soluble solids determined with Bausch and Lomb refractometer, 0.25 percent scale. 2Mean separation within columns by Duncan's multiple range test, 5 percent level. [10] APPENDIX TABLE 4. RESPONSE OF TASTE PANEL TO QUALITY OF WATERMELON CULTIVARS AND BREEDING LINES, AUBURN, ALABAMA, 1982 Cultivar or e breeding line AU-Jubilant .................... AU-Producer ................... Charleston Gray ............... Crimson Sweet ................ Jubilee ........................ Color 8.1' 7.8 7.5 7.8 7.6 Texture 8.1 8.1 7.8 8.0 7.9 Flavor 7.7 8.4 7.1 8.0 7.3 Average 7.97 8.10 7.47 7.90 7.60 'Response index: 9-10 = excellent, 7-8 = good, 5-6 = acceptable, below 5 = unacceptable. APPENDIX TABLE 5. FLESH COLOR OF WATERMELON CULTIVARS AND BREEDING LINES, AUBURN, ALABAMA, 1982' Cultivar or breeding line AU-Jubilant ........... AU-Producer .......... Charleston Gray ........ Crimson Sweet ......... Jubilee ................ L 43.55 39.29 39.16 38.27 41.77 Hearts a 31.05 29.55 30.95 28.58 29.46 b 15.33 14.85 15.25 14.60 15.15 L 39.92 39.23 38.84 38.19 38.84 Subseed a 29.75 24.53 27.17 23.97 27.17 b 14.60 15.08 14.73 14.60 14.73 'Hunter color difference values standardized to red plaque; L = 68.7, a = 23.0, and b = 9.4 where L = total light reflectance, a = red, and b = yellow APPENDIX TABLE 6. RIND FIRMNESS (PUNCTURE TEST) OF WATERMELON CULTIVARS AND BREEDING LINES, AUBURN, ALABAMA, 1982' Cultivar or breeding line Stem end Top side firmness Middle Blossom end kg/cm 58.4 28.0 26.9 23.5 22.6 2 Ground side firmness Middle Blossom Average Stem end end kg/cm 58.0 27.2 26.7 23.4 22.8 2 AU-Jubilant ......... AU-Producer ........ Charleston Gray ..... Crimson Sweet ...... Jubilee ............. kg/cm2 60.4 28.5 27.8 24.6 23.4 kg/cm 34.2 20.3 17.0 13.7 12.5 2 kg/cm2 55.6 26.3 25.4 22.6 21.5 2 kg/cm 2 33.3 19.7 15.7 12.3 11.6 kg/cm 50.00 20.67 23.25 20.02 19.10 2 'Puncture test performed with Instron 1122 Instrument, 1-cm Magnus Taylor probe. Punc- ture made at 5-cm intervals beginning at stem end. [11] -nuii~li:~LxptkuhcliU" Ii :.i L e liu 'tLaOfl "ystemn AUBURN UNIVERSITY With an agricul tural research unit in evenr najor soil area, Auburn Universitv serves the needs of field crop, livestock, forestry , and horticultural producers in each region in Alahama. Even citi zen nf the State has a stake in this research program, since any advantage from new and more economical way s nf produc- A 0 ing and handling farm products directly benefits the consuming public. ® Main Agricultural Experiment Station, Auburn. a E. V. Smith Research Center, Shorter. 1. Tennessee Valley Substation, Belle Mina. 2. Sand Mountain Substation, Crossville. 3. North Alabama Horticulture Substation, Cullman. 4. Upper Coastal Plain Substation, Winfield. 5. Forestry Unit, Fayette County 6. Chilton Area Horticulture Substation, Clanton. 7 Forestry Unit, Coosa County 8. Piedmont Substation, Camp Hill. 9 Plant Breeding Unit, Tallassee. 10. Forestry Unit, Autauga County 11. Prattville Experiment Field, Prattville. 12. Black Belt Substation, Marion Junction. 13 The Turnipseed-Ikenberry Place, Union Springs. 14. Lower Coastal Plain Substation, Camden. 15. Forestry Unit, Barbour County. 16. Monroeville Experiment Field, Monroeville. 17. Wiregrass Substation, Headland. 18. Brewton Experiment Field, Brewton 19. Solon Dixon Forestry Education Center, Covington and Escambia counties. 20. Ornamental Horticulture Substation, Spring Hill. 21. Gult Coast Substation, Fairhope. -~= 7-n