CIRCULAR 271 MAY 1984 AU-ROADSIDE An Excellent Quality Plum for Home Use and Local Markets Oq F.r L a: Xaa FZ2 Qrn .J LL0 m 'I Q~ CONTENTS Page INTRODUCTION. ............................................ 3 DISEASE RESISTANCE........................................5 FRUIT QUALITY. ......................................... 5 8 8 YIELDS...................................................... STORAGE ................................................. OUTSTANDING CHARACTERISTICS............................... 9 AVAILABILITY OF TREES ....................................... ACKNOWLEDGMENTS .................... 9 10 FIRST PRINTING 3.5M, MAY 1984 Information contained herein is available to all persons without regard to race, color, sex, or national origin. AU-ROADSIDE AN EXCELLENT QUALITY PLUM FOR HOME USE AND LOCAL MARKETS J.D. NORTON, J.M. SNELL, D.A. SMITH, and 1 K.S. RYMAL INTRODUCTION AU-ROADSIDE is a new plum variety developed by the Alabama Agricultural Experiment Station, Auburn University, for, growing in areas where sufficient chilling of 700 hours of temperature below 45°F occurs. AU-Roadside has proven its ability to produce high yields of excellent quality fruit where there are certain fruit and tree disease problems. The new variety is superior to the Ozark Premier variety in yield, fruit quality, tree vigor, disease resistance, and tree longevity. Therefore, AU-Roadside is being released as a direct replacement for the Ozark Premier variety. AU-Roadside was selected from a cross between Ozark Premier and Methley varieties. The cross was made in 1965 and the seedling was tested as Ozark Premier F-2, see figure. It has resistance or tolerance to black knot, bacterial canker, bacterial fruit spot, and plum leaf scald, prevalent diseases of plum, tables 1 and 2. Such resistance is particularly important in the Southeast where prevalence of these diseases and susceptibility of commercial varieties has discouraged plum production. Its resistance to bacterial and fungal diseases came from the Ozark Premier parent, while excellent fruit quality was inherited from both parents. Trees of AU-Roadside are vigorous, spreading with dark green leaves. Professor, Research Associate, Associate Professor, and Associate Professor, respectively, Department of Horticulture. r---P so//ciniC r-Ozark P solicinia P cerosifern AU-Roadside P so/icinia P cerosifero Pedigree of AU-Roadside plum. V TABLE 1. DIsEASE RESISTANCE OF PLUM VARIETIES IN EXPERIMENTAL PLANTINGS AT AUBURN, CAMP HILL, CLANTON, CULLMAN, FAIRHOPE, AND HEADLAND Variety AU-Producer... AU-Roadside... Bruce.......... Crimson........ Homeside ...... Methley....... Morris......... Ozark Premier.. SantaRosa Disease index' Bacterial Bacterial Bacterial Black Brown rot knot fruit spot leaf spot canker 0 0 0 0 0 3 1 0 5 0 0 0 0 0 5 2 1 5 0 0 0 0 1 5 2 1 5 1 0 0 0 1 5 5 1 0 2 2 4 1 3 3 2 3 3 Plum leaf scald 1 1 4 3 1 4 2 4 5 v. fruit, leaves, and trees infected with bacterial canker, bacterial fruit spot, bacterial leaf spot, and black knot. TABLE 2. DISEASE INDEX' RATINGS FOR BLACK KNOT, BACTERIAL CANKER, BACTERIAL LEAF SPOT, AND BACTERIAL FRUIT SPOT OF PLUM VARIETIES AFTER 5 YEARS IN ALABAMA GROWER ORCHARDS 'Disease index: 0= 0.7 .5 1.3 .7 1.0 4.2 2.4 1.2 3.8 0, 1= 1-20, 2 = 21-40, 3= 41-60, 4= 61-80, 5 = 81-100 percent of Variety tees.Disease Numbe of Nubrotes Black Planted Living knot 47 1,061 251 239 180 index' Bacterial Bacterial Bacterial canker leaf spot fruit spot 0 0 .4 5.0 1.3 Av. 0 .08 .36 4.87 .55 AU-Roadside ... 50 Crimson........ 1,087 Homeside....... 278 Methley......... 275 Ozark Santa Rosa....... Premier. . 0 0 .7 4.5 .7 0 .3 .4 5.0 2.0 0 0 0 5.0 0 375 of tree, fruit, and leaves infected with black knot, bacterial canker, bacterial fruit spot, and bacterial leaf spot. [4] 'Disease index: 0= 150 124 0 5.0 5.0 5.0 3.75 0, 1= 1-20, 2= 21-40, 3= 41-60, 4= 61-80, and 5= 81-100 percent DISEASE RESISTANCE AU-Roadside is highly resistant to bacterial canker (Pseudomonas syringae, Van Hall), bacterial fruit spot [Xanthomonas pruni (E. F. Smith), Dows], bacterial leaf spot (X. pruni) and black knot (Dibotryon morbosurn), tables 1 and 2. A tolerance to plum leaf scald is also present in the trees, table 1. FRUIT QUALITY Fruits of AU-Roadside have dark red (currant red, HCC 46A)2 skin and flesh. Fruit quality is excellent for fresh market which makes the variety adaptable for home, roadside, and local markets. Fruits were rated acceptable in canned fruit tests, table 3. Fruit have adequate firmness for handling, packing, and shipping to commercial markets, table 4. Maturity date is about 1 week before Ozark Premier, able 5. IThe plant is self fruitful, flowers profusely, and sets a heavy crop. TABLE 3. MEAN QUALITY EVALUATIONS' OF 12 CANNED PLUM VARIETIES Variety AU-Producer ...... AU-Roadside ...... Crimson .......... Giant Cherry ...... Methley .......... Morris............. Ozark Premier..... Color 8 8 8 5 8 8 7 Texture 8 8 8 6 8 8 7 Flavor 8 8 8 7 8 8 6 Overall quality' 8.0 8.0 8.0 6.0 8.0 8.0 6.7 Red June......... Sapa .............. 6 8 8 8 8 7.4 8.6 Starking Delicious. . . 10 8 7 5 6.7 'Mean scores of' an expert panel (3-4 panelists) were obtained on the canned plums after at least 6 weeks warm-storage. Numerical scores as follows: 9 or 10 = highly acceptable, 7 or 8 = acceptable, 5 or 6 = barely acceptable, below 5 = unacceptable. 'Overall ratings are the means of all the panelists' three quality ratings. 'Horticulture Color Chart, Royal Horticulture Society, London. [5] TABLE 4. FRUIT CHARACTERISTICS OF PLUM VARIETIES Variety AU-Producer........ Fruit set 51 Flesh Skin color st clr corness color dark red Size Shape FlvrTx 51 5 3 5 5 5 3 5 5 Firm- Ston freeness cling semi-cling cling cling cling cling cling semi-cling cling e ur 5' 5 3 5 5 5 5 5 5 Soluble solids Pct. In. dark red 13/4-2 51 to purple AU-Roadside......... 5 dark red dark red 2-214 5 Bruce...............S5 orange to red orange to red 13/4-2 5 Crimson............. 5 crimson red crimson red 11/2-134 5 '~Homeside............ 5 cream orange to 214-21/ 5 light red Methley............. 5 dark red dark red 1-114 5 to purple Morris.............. 5 light red light red 4' Ozark Premier .... S cream red to purple 2-214 5 Santa Rosa...........4 dark red 11'4-11/ 5 to purple 'Rating index: 5= excellent, 4= good, 3= fair, 2 =poor, and 1= very poor. 5' 4 3 5 4 3 5 4 5 16.5 17.2 9.4 16.3 18.8 18.5 13.4 15.7 16.7 'red TABLE 5. BLOOM AND HARVEST DATES AND YIELD OF PLUM VARIETIES Auburn Variety datem at dt daedate Camp Hill Clanton Headland Yield' Bloom Harvest date Yil ie Bloom date Harvest date Yield 5 5 3 5 5 3 5 4 3 datem dYieldt 3-21 3-22 3-22 3-22 3-20 3-24 3-22 322 3-26 at el 7-2 5 3-17 AU-Producer....... 3-20 6-27 5 3-18 5 3-20 7-13 5 3-20 AU-Roadside....... 3-22 7-4 7-5 3 3-17 SBruce'............ 3-20 6-29 2 3-17 Crimson........... 3-22 7-14 5. 3-20 7-20 5 3-19 Homeside.......... 3-20 7-5 5 3-18 7-12 4 3-10 3 . . . . . . . . . Methley 3-22 6-10 3 3-20 6-16 3 3-20 5 3-20 Morris............ 3-22 6-17 5 3-20 6-23 2-20 7-10 4 2-18 7-18 4 3-18 Ozark Premier.. 4. . . . . . . . 3-24 7-5 3 3-21 7-9 3 3-22 Santa Rosa 'Yield index: 0 = 0, 1= very low, 2= low, 3= fair, 4= good, and 5= excellent. 'Trees short lived due to ring spot virus. 3 Trees short lived due to black knot and bacterial canker. 4 Trees short lived due to bacterial canker. 7-1 7-10 7-3 7-18 7-10 6-14 6-21 7-15 7-8 6-24 6-29 6-26 5-7 7-1 6-7 6-14 7-5 7-1 5 5 3 5 5 5 5 5 5 YIELDS The new variety has been in trials as Ozark Premier F-2 at several locations of the Alabama Agricultural Experiment Station system and in grower trials. It compares favorably with other varieties in yield. Production has been highest in central and southeast Alabama,#table 6 Average yields of marketable fruit per tree were 122.2 pounds and 117.4 pounds, respectively, from 3- and 4-yearold trees. TABLE 6. YIELD OF FRUIT OF AU-ROADSIDE AT AUBURN, CAMP HILL, HEADLAND, AND THORSBY, 1976 TO 1982' Fruit yield per tree Headland Camp Hill Auburn Lb. Lb. Lb. 43.3 8.7 46.5 3 ................ 23.4 8.7 106.7 4 ................. 158.3 26.0 165.8 5 ................. 148.5 87.6 148.7 6 ................. 106.4 0 114.5 7................. 'Yield = pounds of fruit per tree. One tree per plot and six replications. Year Thorsby Lb. 23.3 24.0 26.9 84.6 67.8 STORAGE Fruits of AU-Roadside store as well as Homeside and Methley, and better than Bruce and Ozark Premier, table 7. TABLE 7. PERCENT MARKETABLE PLUM FRUIT AFTER STORAGE AT 32 F 0 Variety Weeks of storage AU-Producer ...... AU-Roadside ...... Bruce ............ Crimson .......... Homeside.......... .. Methley .......... Morris............ Ozark Premier..... Santa Rosa ........ 3 Pct. 100 95 20 100 95 95 100 90 100 6 Pct. 90 70 5 90 65 70 90 65 80 9 Pct. 65 20 0 65 15 20 65 15 45 12 Pct. 30 0 0 30 0 0 30 0 20 14 Pct. 15 0 0 15 0 0 15 0 5 [8] OUTSTANDING-CHARACTERISTICS Two characteristics, tree vigor and tolerance to plum leaf scald, delineate the. primary improvements of AU-Roadside over Ozark Premier. Trees of AU-Roadside are vigorous and show only traces of plum leaf scald, whereas trees of Ozark Premier grow much slower and are highly susceptible to plum leaf scald. Tree vigor is a primary selective criterion in the Southeast, and the relationship of plum leaf scald to phony peach makes resistance important. Three other characteristics, ripening date, growing season, and skin color at maturity, may be taken collectively as another important advantage of AU-Roadside. AU-Roadside ripens 9 days earlier, has a shorter growing season by 7 days, and is more fully colored at any comparable stage of maturity than Ozark Premier, table 5 Another improvement of AU-Roadside over Ozark Premier is the increased tree longevity of AU-Roadside. In test orchards at five Alabama locations and at Byron, Georgia, trees of AU-Roadside were in extremely healthy condition. AVAILABILITY OF TREES Trees of AU-Roadside should be available from wholesale and retail nurseries for planting in the winter of 1984-85. A limited supply of budwood may be obtained from J. D. Norton, Department of Horticulture, Auburn University, Alabama 36849. [9] ACKNOWLEDGMENTS The author gratefully acknowledges the essential assistance of H.M. Bryce, Main Station, and C.C. Carlton and K.C. Short, Chilton Area Horticulture Substation, Clanton, in evaluation and propagation of the varieties. Valuable assistance was rendered by M. H. Hollingsworth, North Alabama Horticulture Substation, Cullman; E. L. Mayton (retired), W.A. Griffey, and H.E. Burgess, Piedmont Substation, Camp Hill; J.G. Starling and H.W. Ivey, Wiregrass Substation, Headland; and E.L. Carden and F.B. Selman, Gulf Coast Substation, Fairhope. The assistance of J. M. Thompson, Geneticist, USDA Tree Fruit and Nut Laboratory, Byron, Georgia, in evaluating the seedling is deeply appreciated. Assistance of growers in conducting commercial grower trials with the material is deeply appreciated. [l1o] AUBURN UNIVERSITY W\ith an Ag.ricultturtl r(etttlch tanit in .\uhurn l1ni\ ersit serveis thte ntXeds oft fitild crolp, livestoctk, foretr tiii. 0 0 retgion in1 in1 cNeN .itiAL aI)anla. zen of the State 1hus a1 stake in this researc h at td lall )ltce tll UrJAI each and horprotdtters 0 13 )tv 0s ical 'A aN s of produc-e ng and hanldling farmt protdntts di retltI henetits the co~nsunming puhlik' 11 20 , 21 ® Main Agricultural Experiment Station, Auburn. E. V. Smith Research Center, Shorter. Tennessee Valley Substation, Belle Mina Sand Mountain Substation, Crossville North Alabama Horticulture Substation, Cullman. Upper Coastal Plain Substation, Winfield. Forestry Unit. Fayette County. Chilton Area Horticulture Substation. Clanton. Forestry Unit, Coosa County. Piedmont Substation, Camp Hill. Plant Breeding Unit, Tallassee. Forestry Unit, Autauga County. Piattville Expeiiieit 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. Solon Dixon Forestry Education Center. Covington and Escambia counties. 20. Ornamental Horticulture Substation, Spring Hill. 21. Gulf Coast Substation, Fairhope. 1. 2. 3. 4. 5 6. 7. 8. 9. 10. 11. 12 13 14. 15. 16. 17. 18. 19.