BREEDING COLD HARDY PEACH CULTIVARS FOR CANADA

Cold hardiness of flower buds and shoot xylem of fully acclimated, detached, dormant shoots of peach genotypes was determined by controlled freezing tests in 1988. Hardiness classifications were based on Redhaven as the standard and 3 classes were established: Class 1 – more hardy than Redhaven, Class 2 – equal to Redhaven in hardiness and Class 3 – less hardy than Redhaven.
Hardiness classifications using T₅₀ values obtained mathematically for flower buds and shoot xylem injury were more discriminating and less variable than those based on percent bud kill or ratings of shoot xylem injury at specific stress temperatures.

An effective breeding strategy was developed that accomplished simultaneous improvement of cold hardiness and other major breeding objectives.
Using this strategy, several new cultivars (Harson, Harrow Beauty, Harcrest) and advanced selections (H7519238, HW249, HW259, HW106) were developed that equalled or surpassed the flower bud and shoot xylem hardiness of Redhaven while possessing most other characters required of commercial cultivars in Canada.

II International Peach Symposium

R. E.C. Layne

https://doi.org/10.17660/ActaHortic.1989.254.11