GROWTH RESPONSES AND PHYSIOLOGICAL STUDIES IN RED RASPBERRY PLANTS TREATED WITH GROWTH REGULATORS

In Norway, physiological studies in buds of red raspberry have gone on for some years.
Most observations are taken on small cuttings after forcing at different times of the year, or after different treatments.

In 1984, spraying with paclobutrazol (PP 333) shortly after the last picking date, lead to growth cessation after a few days.
The buds entered the dormant stage early, and leaf drop was earlier than on untreated canes.
The treatment had very little or no effect at all on number of dead buds in the spring.
In May and June, the new vegetative growth was dwarfing in plants sprayed with PP 333, compared to untreated plants.

Canes sprayed with gibberellic acid (GA) had a new vegetative growth flush in August and September.
The leaves did not abscise at normal time, and the buds entered the dormant stage late.
Some of the buds did not enter deep dormancy at all.
Many buds on such canes were killed during the winter.

The ability to form callus at the base of the cuttings was highest in autumn and spring, but low during the winter.
Callus formation was not dependent on treatments.

IV International Rubus and Ribes Symposium

F. Maage

https://doi.org/10.17660/ActaHortic.1986.183.42