HARPIN PROTEIN APPLICATION IMPACTS FRUIT YIELD, SIZE AND RETENTION OF PEACH FRUIT

Harpin proteins are implicated in plant defense responses.
Early pest management work with these proteins also indicated horticultural impacts on fruit production.
During the summers of 2002 through 2004, field trials were conducted assessing the impact of Harpin protein application to peach trees at bud break, petal fall, pit hardening or pit hardening +21 days on fruit retention, yield, size and post harvest quality.
Trials were conducted with the early season, ‘Springcrest’, and the mid-season, ‘Harvester’. In each year of the trial the pit hardening and pit hardening +21 days treatments caused significant increases in fruit yield primarily by affecting fruit size and to a small degree by impacting fruit retention.
In the last year of the trial, a set of harpin protein treatments was made with and without the addition of blossom thinning, to increase the size of the early cling cultivar, ‘Springcrest’. The combination of size increasing treatments did not significantly increase size of harpin protein treatment effect over blossom thinning alone.
Thus, harpin protein application may provide size improvement similar to blossom thinning alone, without the risk involved for early crop loss due to frost in the southeastern USA.

VI International Peach Symposium

K.C. Taylor

Messenger STS®, pit hardening, blossom thinning

https://doi.org/10.17660/ActaHortic.2006.713.34