Growth and yield of 'redhaven' peach on nineteen rootstocks at twenty north american locations

Nineteen Prunus rootstock cultivars and selections budded with 'Redhaven' peach were planted at 20 locations in North America in 1994 as a uniform planting of the NC-140 Cooperative Regional Rootstock Project. The rootstocks included peach seedlings from 'Lovell', 'Nemaguard', 'Bailey', 'Tennessee Natural 281-1', 'Stark's Redleaf', 'GF 305', 'Higama', 'Montclar', 'Rubira', 'Chui Lum Tao', 'Tzim Pee Tao', 'H7338013', 'H7338019', 'BY520-8' and 'Guardian® BY520-9'. Clonal rootstocks included 'Ishtara', 'Myran', 'S.2729' and 'Ta Tao 5' interstem on 'Lovell'. Data were summarized across the 20 sites in 18 states and provinces over eight years. 'Myran' was the most vigorous rootstock followed by 'S.2729' and 'Guardian® BY520-9'. 'Ishtara', 'Tzim Pee Tao' and 'Chui Lum Tao' produced the smallest trees. Fruit weight was significantly influenced by rootstock as 'Redhaven' fruit from 'BY520-8' and 'Ta Tao 5' interstem trees were smaller (~10 g) and fruit from 'Ishtara' and 'H7338013' were larger (6-7 g) than fruit from trees on 'Lovell'. Cumulative fruit yield (1996-2001) significantly varied among rootstocks, and yield differences were evident among locations as the highest cumulative fruit yields were from Ohio, north central New Jersey, Maryland and South Carolina. No rootstock yielded significantly more than 'Lovell'. However, 'GF 305', 'Montclar', 'Guardian® BY520-9' and 'H7338019' yielded equivalent to 'Lovell'. In contrast, 'Ishtara', 'Chui Lum Tao', 'Tzim Pee Tao', 'Bailey', 'Higama' and 'Rubira' and the 'Ta Tao 5' interstem trees often had significantly lower yields than 'Lovell'.