SWEET CHERRY TREE RESPONSE TO HYDROGEN CYANAMID TREATMENT UNDER LOW CHILLING CONDITIONS

In the north of Chile in the irrigated valleys of Elqui, Limarí and Choapa, chilling hours vary from 150 to 800, depending on the altitude.
High daytime temperatures can occur during winter that reduces the accumulation of chilling hours needed for sweet cherry (Prunus avium L.) bud break.
To overcome this effect, 1.25% hydrogen cyanamid (HC) plus 2% mineral oil treatments were used on ‘Brooks’ and ‘Newstar’ sweet cherry trees and the effects were evaluated during three seasons.
HC treatments were applied every week during June, July and August.
Time to full bloom, flowering and fruit development were measured in all subsequent seasons.
Control trees had late flowering and a long bloom period; as a consequence, twigs exhibited simultaneous development of both fruit and flowers.
The use of HC treatments advanced full bloom up to 60 days and the flowering period was almost cut in half compared with the control treatments.
Fruit set was not dependent on flowering time or HC treatment.
The results showed that HC is a useful tool to advance and concentrate cherry bloom.
A minimum level of chilling is required for an adequate response to HC.

V International Cherry Symposium

G. Lemus

Prunus avium, endodormancy, plant growth regulation

https://doi.org/10.17660/ActaHortic.2008.795.109