4 ~,-.P - '4 CONTENTS Page Variety Development...........................3 Origin and Breeding History ............................... Disease Resistance.................... ......... Fruit Characteristics ......... ........................... Summary.... .... .......................... Pest Control........................................7 Availability ofSeed..................................... Literature Cited........................................ Appendix.....................9.......... First Printing 3.5M, March 1993 Information contained herein is available to all persons without regard to race, color, sex, or national origin. 4 5 5 7 7 9 AU-GOLDEN PRODUCER: A HIGH QUALITY, DISEASE RESISTANT WATERMELON FOR THE SOUTH J.D. Norton, G.E. Boyhan, D.A. Smith, and B.R. Abrahams' AU-GOLDENgrowing conditions in the Southeastern is a riety adapted to Producer multiple disease-resistant watermelon va- United States. It has resistance to anthracnose (Colletotrichum laginarium, race 2), Fusarium wilt (Fusarium oxysorium niveum), downy mildew (Pseudoperonospora cubensis), 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 of watermelons. 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 (1,2,8). VARIETY DEVELOPMENT The discovery that certain plant introductions (PI 189225 and PI 271778) were resistant to race 2 anthracnose (7) and gummy stem blight (5,6) led to the initiation of an Alabama Agricultural Experiment 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, were released as AU-Jubilant and AU-Producer, respectively (4). The AW-1001CSY breeding line is being released as AUGolden Producer. Professor, Research Associate, former Associate Professor, and Technician of Horticulture. 'Respectively, ORIGIN AND BREEDING HISTORY AU-Golden Producer was developed in the Department of Horticulture at Auburn University. It originated from a mutant plant found in an isolated planting of breeder seed of AU-Producer (see figure). AU-Golden Producer has multiple disease resistance to anthracnose (races 1 and 2), downy mildew, Fusarium wilt, and gummy stem blight. Resistance to gummy stem blight and race 2 anthracnose, secured from PI 189225, was incorporated into the breeding line AW-76-3 (AU-3) through a screening program that utilized an incubation chamber and greenhouse to eliminate susceptible plants from the population (see figure) (1,3,5,6). Resistance to downy mildew and Fusarium wilt was secured from both parents. AU-Golden Producer has been grown as AW-83-1001CSY in trials at the E.V. Smith Research Center, Shorter, and at a number of Alabama Agricultural Experiment Station research facilities throughout the State, in the Southern Cooperative Watermelon Trials in other southern states, and in demonstration plantings by commercial growers. 1982 Field 1983 Field 1984, 1985, 1986 Field 1990 Field I I Pedigree of AU-Golden Producer [4] DISEASE RESISTANCE AU-Golden Producer has been rated for resistance to race 2 anthracnose, Fusariumwilt, and gummy stem blight in tests at locations in Alabama and other southern states (Table 1). Resistance to race 2 anthracnose and gummy stem blight was incorporated into the breeding line through a screening program that utilized an incubation chamber and greenhouse to eliminate susceptible plants from the populations (1,3,5,6). Multiple disease resistance of AU-Golden Producer has been excellent in field plantings. TABLE 1. DISEASE INDEX RATINGS FOR RESISTANCE TO ANTHRACNOSE, FUSARIUM WILT, AND GUMMY STEM BLIGHT Disease index' Cultivar Charleston Gray ............ Crimson Sweet ............. Jubilee .................... AU-Producer............... AU-Golden Producer......... Anthracnose race 2 5 3 3 2 2 Fusarium wilt 3 2 35 1 1 Gummy stem blight 5 5 2 2 'Disease index: 0 = no injury to 5 = all plants severely injured. FRUIT CHARACTERISTICS AU-Golden Producer was found to be superior to Crimson Sweet (a similar cultivar) in yield, quality, and disease resistance and comparable to that of AU-Producer. Yield of fruit was higher for AU-Golden Producer than for Crimson Sweet, Jubilee, and Charleston Gray and comparable to that of AU-Producer (Table 2). The fruit of AU-Golden Producer are round to oblong-round in shape with few culls. Fruit weight was greater for AU-Golden Producer than for Crimson Sweet and compares favorably with other cultivars (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 measures about 3/4-inch thick. The rind color is light green with dark green stripes. The flesh is bright yellow-orange, firm but not tough. Rind and flesh characteristics make the melons well-adapted to shipping. Rind firmness was higher for AU-Golden Producer than for Crimson Sweet (Appendix Table 5). The 2 flesh color of the fruit was a bright yellow orange (23A ). Taste tests indicated that the edible quality (color, texture, and taste) was higher in AU-Golden Producer than Charleston Gray, Crimson Sweet, and Jubilee and similar to AU-Producer. Mean total soluble solids of AUGolden Producer flesh was higher than for the other varieties (Table 2). 2 RHS Colour Chart, The Royal Horticultural Society, London. [51 TABLE 2. YIELD AND FRUIT CHARACTERISTICS OF VARIETIES OF WATERMELONS, FIVE ALABAMA LOCATIONS, 1988-1991 Variety Yield/ acre Lb. Charleston Gray .............. Crimson Sweet ............... Jubilee ..................... AU-Producer ................. AU-Golden Producer .......... 26,645 23,213 26,808 26,108 27,045 Fruit weight Lb. 19.2 18.0 21.3 19.0 18.8 Soluble solids' Pct. 9.8 10.4 9.6 10.8 10.8 7.3 8.0 7.9 8.2 8.2 0.44 .62 .43 .84 .84 0.56 .86 1.00 .75 .75 Quality preference 2 Width/ length ratio Rind thickness Rind firmness 3 In. 23.3 20.0 19.1 25.0 25.2 80 75 90 75 75 Gray, net Green striped Green striped Green striped Green striped Days to maturity Rind color 'Total soluble solids determined with Bausch and Lomb refractometer, 0 - 25 percent scale. 2 Response index: 9 - 10 = excellent, 7 - 8 = good, 5 - 6 = acceptable, and below 5 = unacceptable. 3 Puncture test performed with Instron 1122 Instrument, 1-cm2 Magnus Taylor probe. Puncture made at 5-cm intervals beginning at stem end. SUMMARY AU-Golden Producer is superior to the current varieties of this type in yield, quality, and disease resistance and similar to that of AU-Producer. AU-Golden Producer is multiple disease resistant, with resistance to race 2 anthracnose, Fusarium wilt, and gummy stem blight. The variety is being released to broaden the base of high quality melons available to growers in the Southern United States. Because the AU-Golden Producer matures early, it fits well into the commercial production program to lengthen the shipping season for any given production area or grower. PEST CONTROL Successful multiple disease resistance is essential for melon production; however, good grower production practices are also important in the control of insects, diseases, and nematodes. Variety testing of AU-Golden Producer further documents that rotation of crops, sanitation, and destruction of weed hosts will greatly reduce pest problems in watermelons. In addition, a spray schedule may be necessary to control insects and diseases, particularly during periods of high humidity and rainfall, regardless of watermelon variety. AVAILABILITY OF SEED An exclusive release of AU-Golden Producer was 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 wholesale and retail outlets. [7' LITERATURE CITED (1) (2) 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.H. HOLLINGSWORTH. 1983. Breeding Watermelons for Disease Resistance. Ala. Agr. Exp. Sta. Highlights of Agr. Res. Vol. 30, No. 2. , G.E. BOYHAN, B.R. ABRAHAMS, J.S. BANNON, J.A. (3) PITTs, M.H. HOLLINGSWORTH, AND J.T. EASON. New Disease Resistant Watermelons Produced in AAES Research. Ala. Agr. Exp. Sta. Highlights of Agr. Res. Vol. 38, No. 4. , R.D. COSPER, D.A. SMITH, AND K.S. RYMAL. AU-Jubi(4) lant and AU-Producer: Quality, Disease-Resistant Watermelon Varieties for the South. Ala. Agr. Exp. Sta. Cir. 280. (5) SOWELL, G.B., JR. 1975. An Additional Source of Resistance to Gummy Stem Blight in Watermelon. Plant Dis. Rptr. 59:413-415. (6) , AND G.R. POINTER. 1962. Gummy Stem Blight Re- sistance of Introduced Watermelons. Plant Dis. Rptr. 46:883-885. , B.B. RHODES, AND J.D. NORTON. 1980. New Sources (7) of Resistance to Watermelon Anthracnose. J. Amer. Soc. Hort. Sci. 105:197-199. (8) SUVANPRAKORN, KAMOLVAN, AND J.D. NORTON. 1980. Inheritance of Resistance to Race 2 Anthracnose in Watermelon. J. Amer. Soc. Hort. Sci. 105:862-865. 181 Appendix APPENDIX TABLE 1. AVERAGE YIELD PER ACRE OF WATERMELON CULTIVARS AND BREEDING LINES AT FIVE LOCATIONS IN ALABAMA, 1988-1991 Cultivar Thorsby Culiman Lb. 32,787 26,207 34,878 25,459 Crossville Lb. 20,628 17,443 29,476 25,479 Fairhope Lb. 30,915 28,987 21,168 25,750 Headland Lb. 20,301 17,183 14,307 20,069 Lb. Charleston Gray...... 28,595 Jubilee ............. 24,244 Crimson Sweet ....... 34,212 AU-Producer......... 34,144 AU-Golden Producer . 33,360 34,269 27,928 25,166 14,506 APPENDIX TABLE 2. YIELD, FRUIT WEIGHT, AND SOLUBLE SOLIDS OF WATERMELON CULTIVARS IN SOUTHERN COOPERATIVE WATERMELON TRI, 1989-1991 Cultivar Yield/acre Lb. Number/acre Fruit weight Lb. Soluble solids Pct. 9.8 9.6 Charleston Gray.......... Jubilee.................. AU-Golden Producer ...... 40,196 42,219 44,120 1,777 1,743 2,084 23.0 34.2 21.1 10.7 APPENDIX TABLE 3. RESPONSE OF TASTE PANEL TO QUALITY OF WATERMELON CULTIVARS AND BREEDING LINES, AUBURN, AL, 1988' Cultivar or breeding line Color Texture 8.1 7.8 8.0 7.9 8.0 = Flavor 8.4 7.1 8.0, 7.3 8.5 Average 8.10 7.47 7.90 7.60 8.17 = 7.8 AU-Producer ........................ 7.5 Charleston Gray...................... Crimson Sweet....................... 7.8 7.6 Jubilee ............................ 7.7 AU-Golden Producer .................. 'Response index: 9-10 unacceptable. = excellent, 7-8 = good, 5-6 acceptable, below 5 [9' APPENDIX TABLE 4. FLESH COLOR OF WATERMELON CULTIVARS AND BREEDING LINES, AUBURN, AL, 19881 Cultivar L 39.29 39.16 38.27 41.77 36.92 Hearts a 29.55 30.95 28.58 29.65 27.42 b 14.85 15.25 14.60 15.15 17.68 L 39.23 38.84 38.19 38.84 35.24 Subseed a 24.53 27.17 23.97 27.17 23.84 b 15.08 14.73 14.60 14.73 16.86 AU-Producer ............... Charleston Gray ............ Crimson Sweet ............. Jubilee ................... AU-Golden Producer ......... 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. 'Hunter APPENDIX TABLE 5. RIND FIRMNESS (PUNCTURE TEST) OF WATERMELON CULTIVARS AND BREEDING LINES, AUBURN, AL, 19881 Top side Cultivar Stem Ground side end Kg Middle Blossom end Kg Stem end Kg Middle BlossomAverage end Kg Kg 28.0 26.9 23.5 22.6 28.3 Kg 26.3 25.4 22.6 21.5 26.4 Kg 25.00 23.25 20.02 19.10 25.17 AU-Producer ........ Charleston Gray ..... Crimson Sweet ...... Jubilee ............. AU-Golden Producer . 28.5 27.8 24.6 23.4 28.6 20.3 17.0 13.7 12.5 20.4 27.2 26.7 23.4 22.8 27.4 19.7 15.7 12.3 11.6 19.9 'Puncture test performed with Instron 1122 Instrument, 1-cm Magnus Taylor probe. Puncture made at 5-cm intervals beginning at stem end. [10] AUBURN UNIVERSITY With an agricultural research unit in every major soil area, Auburn University serves the needs of field crop, livestock, forestry, and horticultural producers in each region in Alabama.~"i Every citizen of the State has a stake in this research program, since any advantage from new 5 . 9 i2 and more economical ways of producing and handling 1516 farm products directly benefits the consuming public. e Research Unit Identification ® Main Agricultural Experiment Station, Auburn. $ 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. E. V. Smith Research Center, Shorter. Tennessee Valley Substation, Belle Mina. Sand Mountain Substation, Crossville. North Alabama Horticulture Substation, Cullman Upper Coastal Plain Substaton, Winf eld. Forestry Unit, Fayette County. Chi ton Area Horticulture Substation, Clanton. Forestry Unit, Coosa County. Piedmont Substation, Camp Hill. Forestry Unit, Autauga County. Prattville Experiment Field, Prattville. Black Belt Substation, Marion Junction. The Turnipseed-Ikenberry Place, Union Springs. Lower Coastal Plain Substation, Camden. Forestry Unit, Barbour County. Monroeville Experiment Field, Monroeville. Wiregrass Substation, Headland. Brewton Experiment Field, Brewton. Ornamental Horticulture Substation, Spring Hill. Gulf Coast Substation, Fairhope.