PERFORMANCE OF NEW PRUNUS ROOTSTOCKS FOR PEACH IN SOUTH CAROLINA

Three rootstock trials consisting of ‘Redtop’ on 14 rootstocks, ‘Redhaven’ on 9 rootstocks and ‘Redhaven’ on 11 rootstocks were planted in 2001, 2002 or 2003, respectively in the Piedmont (2001, 2002) and Sandhills (2003) of South Carolina. In the 2001 and 2002 plantings, ‘Cadaman®’, ‘SLAP’, ‘Lovell’, ‘Pumiselect®’ and ‘Guardian® SC-17’ were the most vigorous; and ‘Adesoto 101’, ‘Julior’, ‘Jaspi’, ‘Mr.S. 2/5’, ‘K146-43’, ‘VVA-1’ and ‘VSV-1’ were the most dwarfing rootstocks. Plum rootstocks ‘Julior’, ‘Jaspi’, ‘Adesoto 101’, ‘Mr.S. 2/5’, ‘VSV-1’ and ‘VVA-1’ had significant root suckering. Mortality was high for ‘Adesoto 101’ and ‘Jaspi’. Many ‘Cadaman®’ trees died of unknown causes by 2005. Within cultivars, there was a 1-2 days range in bloom date and a 4-5 days range in maturity date among rootstocks. Trees on ‘Penta’, ‘Julior’ and ‘Adesoto 101’ bloomed earliest, and trees on ‘Cadaman®’ bloomed last. ‘Redhaven’ fruit from trees on ‘Mr.S.’ 2/5, ‘Adesoto 101’, ‘VSV-1’ and ‘VVA-1’ rootstocks matured earliest, 4-5 days before ‘Lovell’. No rootstock produced fruit significantly larger than those on ‘Lovell’. Trees on ‘Mr.S. 2/5’ and ‘Jaspi’ produced the smallest fruit. Trees on ‘Cadaman®’, ‘SLAP’, ‘SC-17’, ‘Bailey’ and ‘Lovell’ had the highest fruit yields, while those on ‘Julior’, ‘Jaspi’, ‘Mr.S. 2/5’, ‘VSV-1’ and ‘VVA-1’ had the lowest. Trees on ‘Bailey’ had the highest cumulative yield efficiency. Most dwarfing rootstocks except ‘VSV-1’ had low yield efficiencies. At the Sandhills trial, which was on a severe bacterial canker replant site, all trees on ‘Adesoto 101’, ‘Monegro’, and ‘VVA-1’, and most trees on ‘K146-43’ died as a result of bacterial canker. ‘Lovell’, ‘Mr.S. 2/5’ and ‘Pumiselect®’ were the only rootstocks with 100% survival in 2005.