1. White Delight Peach Series David Byrne and Natalie Anderson Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843-2133, USA Dr. David H. Byrne d-byrne@tamu.edu Natalie Anderson n-anderson @tamu.edu ABSTRACT In the late 1990s, the Prunus Breeding and Genetics Program began to develop a series of low acid white fleshed peach cultivars adapted to the medium chill zone of the southern USA. This work has resulted in 4 new peach cultivars that ripen consecutively from late May to mid July in the medium chill zone of Texas. This is the first series of low acid white-fleshed peaches released for the medium chill zone of the USA. All of these varieties bloom within several days of ‘June Gold’, and have similar sizes and skin blush color but better fruit shape and firmness as compared to ‘June Gold’ (Table 1). These cultivars resulted in crosses done between adapted breeding materials with low acid white peaches/nectarines from California, Japan, and China. CultivarFull bloom Ripe dateWeight (g)Firm- ness Regal13 Mar ab 21 May d 105 d 7.0 b WD105 Mar e 25 May cd 138 ad 6.8 b June Gold09 Mar be 01 Jun c 130 ad 6.0 c Scarlet Pearl16 Mar a 16 Jun b 165 a 7.3 ab WD206 Mar e 13 Jun b 141 ad 7.8 a WD312 Mar ac 29 Jun a 148 ac 7.1 ab WD411 Mar ad 10 Jul a 144 ac 7.7 a Table 1. Bloom time, ripe date, fruit size and firmness of White Delight (WD) peaches in Fairfield, Texas (2006-2011). Parentage of White Delight Peaches Adaptation of White Delight Peaches White Delight 1 - Late May White Delight 2 - Mid June White Delight 3 - Late June White Delight 4 - Early July Full bloom = 60-80% flowers open, Ripe date = date when 20% of the fruit is firm ripe. Rating scale 0 – 9; 0-4 = unacceptable, 5 = marginal, 6 = good, 7 = very good, 8-9 = excellent for commercial use. Mean separation within columns by Duncan’s Multiple Range test at the 5% level. Items with the same letter are not significantly different. No letters within a column indicates no significant differences. WD1=White Delight One, WD2=White Delight Two, WD3=White Delight Three, WD4=White Delight Four WD1TX2492-1 10-12-27NE EarligrandeFLA5-58 Early Amber ChiyohimeKoyohakutoSaotomeHakuhoRobin WD2TX4D46WTexRoyalNJ239Early Amber Unknown Summer sweet 23R236 OHenry X Babcock F2 Unknown44EB108 Redwing x EarlyFlame Unknown WD3 and WD4 TXW1591-1 Tropic Sweet FLA46-95Merril PrinceUnknownKgoldFLA4-65FLA2-12PalomarFLA68-50FLA8B21UnknownFLA9-6N Zaohong zhu JingyuOkuboOkitsuA3697761A197Nectared 4NJ572967A109NJN55RR122-15Unknown The White Delight peach series bloom within a few days of ‘June Gold’ in the medium chill zone (Table 1). Based on the relative bloom times of standard cultivars, WD1 and WD2 need about 550 chilling units (CU) whereas WD3 and WD4 need about 700 chilling units for proper flowering and fruiting. All four have produced consistently in zones 2 (450-550 CU), 3 and 4 (550-750 CU) of Texas. Of these, only WD2 was tested in zone 5 (350-450 CU) where although it had a more prominent suture, it consistently ripened large crops of high quality low acid white fleshed peaches (Fig 1). All the crosses were between low to medium chill, acid, yellow fleshed peach selections from the TAMU program with high quality low acid, white fleshed genotypes from Japan (‘Chiyohime’), California (‘Summersweet’) and China (‘Zaohongzhu’). These new cultivars were developed using germplasm from multiple programs both in the USA and abroad (see pedigree diagrams). Ripening and Quality of the White Delight Peaches This series consist of 4 cultivars that ripen consecutively with about 2 weeks between the first ripe dates between the cultivars (Table 1). WD1, WD3, and WD4 are clingstone whereas WD2 is a semifreestone white peach. All these have large fruit size (Table 1) and good to excellent flavor when properly managed and thinned. The mean soluble solids for these cultivars when picked mature ranged from 12.0 to 14.2 Brix. All have a creamy white ground color with a red blush over 30% to 80% of the fruit surface depending on the cultivar and environmental conditions. Acknowledgement The contribution of Takashi Haji of the National Institute of Fruit Tree Science at Tsukuba, Japan who supplied the pollen of ‘Chiyohime’ and of Lirong Wang of the Zhengzhou Fruit Research Institute in Zhengzhou, Henan, China who supplied the ‘Zaohongzhu’ pollen are gratefully acknowledged. These cultivars would not exist without their generous cooperation. Figure 1. Chilling zones in Texas. Terrell Fairfield College Station Floresville