Low-Temperature Susceptibility of ‘Redhaven’ Peach Floral Buds on Various Rootstocks in the 1994 NC-140 Trial

Abstract

‘Redhaven’ budwood was collected from Missouri, Ohio, and South Carolina from January 1997 through March 1999 and subjected to controlled freezing tests to evaluate the relative cold tolerance of peach floral buds on rootstocks included in the 1994 NC-140 trial. Floral bud hardiness was not affected by rootstock at any site when samples were collected in early November 1997 and 1998. However, in January 1997 and 1999, the T50 values of floral buds on Ta Tao 5 interstem/Lovell rootstock were consistently low (≤ -19.1°C ) in Missouri, whereas those of buds on BY520-8 and S.2729 trees were high. At the Ohio site, which had fewer rootstocks in the trial, floral buds on Tennessee Natural 281-1 trees were more cold tolerant than those on other trees in March 1998 and 1999, while floral buds on BY520-9 were less tolerant. In South Carolina, none of the rootstocks conferred greater floral bud hardiness than Lovell at any sampling date. However, buds on H7338013 and Ta Tao 5 interstem/Lovell trees had lower T50 values than those on Tennessee Natural 281-1, Myran, and Nemaguard in January 1997 and late February 1999. Thus, at the two sites that had Ta Tao 5 interstem/Lovell, floral bud hardiness was similar to, or better than that of Lovell trees.