Modifying Bloom and Harvest Date of Peach with Interstems and Rootstocks

Abstract

Avoidance of spring freeze injury through bloom delay can provide more consistent cropping in areas prone to late spring frosts. In this study, a Ta Tao #6 interstem significantly retarded bloom of ‘Springcrest’ and ‘Harvester’ peach, averaging nearly 8 days delay. Significant freeze events occurred in two of the four cropping years observed. However, the bloom delay provided by a Ta Tao #6 interstem was sufficient in only one of these events to significantly improve fruit yield. Attempts to close a harvest gap between ‘Harvester’ and ‘Redglobe’ peach cultivars by altering fruit maturation were only partially successful. Fruit maturation of ‘Harvester’ and ‘Springcrest’ on Ta Tao #6 interstem trees was delayed on average 3.6 days over the 3 cropping seasons observed when compared to that of their 2-piece counterparts on Lovell seedling rootstock without the interstem. However, 2-piece trees of ‘Redglobe’ on Halford seedling rootstock failed to advance maturation compared to their counterparts on Lovell rootstock and the net shift in the harvest window of ‘Harvester’ peach was insufficient to close the 11-12 day gap observed between the two cultivars. Nevertheless, the use of Ta Tao interstems to delay bloom and fruit maturation may offer growers a useful tool to manage their spring frost risk and harvest management.