318 FIELD PERFORMANCE OF 28 PRUNUS ROOTSTOCKS AND INTERSTEMS IN SOUTH CAROLINA

Abstract

A `Redglobe' peach orchard budded to 22 rootstock cultivars was planted in 198X on a Lakeland sand near Columbia, SC. Six of the 22 cultivars were also used as interstems on Nemaguard. The rootstocks tested were Lovell, Halford, Nemaguard, Bailey, Tennessee Natural, Tzim Pee Tao, Rutgers Redleaf, Higama, Rubira, Montclar, GF 305, Juseito, Myran, Ishtara, S.2729. St. Julian A, Citation, Marianna 2624, GF 557, GF 677, (S×R 185)6 and `Redglobe' own-rooted. Trees on Marianna 2624 grew poorly and eventually died from incompatibility. Plum hybrid rootstocks St. Julian A. Ishtara and Myran were susceptible to Pseudomonas syringae. Some peach X almond (S×R 185)6 trees died from unknown causes. Tzim Pee Tao was the only rootstock to delay bloom significantly later (1.5 days) than Lovell. All Nemaguard interstem combinations and Tzim Pee Tao had significantly more-rootstock suckers. Nemaguard, Myran and Higama trees were 25 to 43% larger in TCSA than Lovell. Ishtara trees were only 61% of Lovell in TCSA. St. Julian A and Citation trees were small, weak and unproductive. The highest yielding rootstocks were Nemaguard (Myran interstem), GF 305, Nemaguard (Ishtara interstem), Montclar and Rubira which averaged 69, 65, 64, 62 and 60 kg/tree, respectively in years 4 through 6.