PRELIMINARY FINDINGS ON THE PROGRESSION OF BUD DORMANCY IN APRICOT IN A MILD WINTER CLIMATE

This paper describes recent studies on the progression of bud dormancy in Prunus armeniaca L. In the first study endodormancy and paradormancy were followed in ‘Palsteyn’ apricot.
The rate of budburst [1/(days to 50% budburst)] in terminal vegetative, lateral vegetative, and reproductive buds was calculated.
Three shoot treatments were evaluated: intact control; upper 10 cm disbudded; and upper 10 cm removed.
No clear paradormant effect was found during the period studied, nor were we able to see differences between the terminal and lateral vegetative budburst.
Treatment effects were only observed on reproductive budburst where flowers opened faster following disbudding.
In the second study the dormancy progression of five apricot cultivars from four locations in South Africa was evaluated.
Cultivars ranged from low (Palstein) to high (Orange Red) chilling requirements.
Locations ranged from low (Robertson, Ladismith) to high (Ceres) chill accumulation.
Rate of budburst was determined in terminal vegetative, lateral vegetative, and reproductive buds.
During autumn, all cultivars showed an important increase of rate of budburst, thus indicating an apparent end of endodormancy.
An ecodormant period followed throughout winter while chilling accumulated.
These results contrast with the accepted concept that under mild winter conditions chilling accumulation during winter results in the release of dormancy in spring.

VIII International Symposium on Temperate Zone Fruits in the Tropics and Subtropics

J.A. Campoy , J. Egea, N.C. Cook, L. Allderman

Prunus armeniaca L., endo-, para-, and eco-dormancy

https://doi.org/10.17660/ActaHortic.2010.872.63