DELAYING BLOOM IN APRICOT AND PEACH TREES

Ethephon treatments (150–200 ppm a.i.) carried out in the 2nd October week resulted in protracted development of flower primordia within the buds during the second half of winter and delaying bloom in springtime.
As for efficiency of treatment, by the time of full bloom of the untreated trees of apricot cvs Kécskei rozsa and Magyar kajszi only 37 and 46 per cent of flowers of the treated trees were open.
A frost of -4°C, occurred at this time, reduced the yield of the untreated trees to half compared to the treated ones.

The buds of untreated trees of peach cv Sunbeam were damaged by winter frost up to 56 per cent, while trees treated in October with Rol-Fruct (an Ethrel-type product) at a rate of 150 ppm (a.i.) or GA₃ (50 ppm) suffered damage only to 31 and 39 per cent, respectively.
The treatment with Rol-Fruct caused a 4-day delay of full bloom, the similar effect of GA₃ was less significant.

Fruit set in treated trees was not affected, or it was slightly increased.

VIII International Symposium on Apricot Culture and Decline

T. Bubán, I. Turi

https://doi.org/10.17660/ActaHortic.1986.192.11