TIMING OF HYDROGEN CYANAMIDE APPLICATION AND FULL-BLOOM, FRUIT MATURITY AND YIELD OF TWO APPLE CULTIVARS

Apple trees (Anna and Bericher cvs.) were sprayed with 3% hydrogen cyanamide (H₂CN₂) on 14/12, 24/12/1990 and 3/1/1991 during the first season and on 20/12/1991, 1/1 and 10/1/1992 during the second season.
Treated trees reached full-bloom and had their fruits mature earlier than the control (sprayed with water at the same dates), regardless of time of application.
Full-bloom advancement ranged from 30–51 and 15–30 days for the Anna trees during the first and second seasons respectively, and from 26–43 and 5–19 days for the Bericher trees during the first and second seasons respectively.
Fruit maturity advancement for the treated Anna trees ranged from 20–48 and 9–28 days during the first and second seasons respectively, and from 23–45 and 7–27 days for the Bericher trees.
Yields of treated trees were less than those of the control.
The reduction in fruit yield compared to that of the control was 19–52 % and 20–44 % for the Anna trees during the first and second seasons respectively, and 27–54 % and 10–42 % for the Bericher trees.
This reduction in yield was mainly due to lower fruit set percentage.

IV International Symposium on Growing Temperate Zone Fruits in the Tropics and in the Subtropics

Gamal M. Hasseeb, Ahmed A. Elezaby

https://doi.org/10.17660/ActaHortic.1995.409.23