FRUIT REGULATION IN PLUMS, PRUNES AND DAMSONS

There is a close connection between yield and quality of plums and damsons.
Besides the characteristic of yield rating of the cultivars, the aspect of optimal yield ability, in correlation with the regulation of bearing is also presented.
As a help of orientation in order to judge the fruit set we offer leaf-fruit-relation or proportions of tree habit volume and flower topophysis.

A late fruit thinning (30–40 days after flowering) based on Ethrel-Amidthin (Etephon-NAAm) lead to a thinning effect between 25 and 35 % of the fruit set.
The addition of Amidthin is very important to limit the induced fruit fall.
Using only Etephon would be uncontrollable and it could cause overthinning.

The late application permits an exact prognosis of the fruit set before application and a calculable thinning effect depending to the Ethrel-concentration.

With a hormonal-fertilizing treatment it is possible to stable dropping sensitive cultivars.
There are good results with the application based on Amidthin (NAAm) and a plant restorative as an aminoacid preparation (Siapton, Aminosol) during a time between fruit set till harvest every 20 days.

VI International Symposium on Plum and Prune Genetics, Breeding, Pomology

H.B. Jacob

Plums, optimal yield efficiency, fruit thinning, fruit stabilizing

https://doi.org/10.17660/ActaHortic.1998.478.19