THE EFFECT OF WINTER CHILLING ON CELL DIVISION AND – MULTIPLICATION PRE-ANTHESIS AND THUS ON FINAL FRUIT SIZE OF ROYAL GALA APPLES IN SOUTH AFRICA

The relative small fruit size of Royal Gala apples in the Western Cape, South Africa, has lead to an unsatisfactory income from the overseas markets, which requires a bigger fruit size.
To address this problem, an investigation in the three main apple producing areas, Elgin and Ceres in the Western Cape, and the Eastern Free State (EFS) was launched in 1995/6. Reproductive buds were collected during winter and examined under the scanning electron microscope (SEM). The number of cells per reproductive bud per area during the winter of consecutive years were then compared to each other and to the amount of winter chilling received per area.
Results showed that high May chilling was beneficial to cell division and resulted in increasing cell numbers and thus potentially bigger fruit at harvest.
Averaged May chilling decreased in the sequence EFS, Ceres and Elgin and cell number followed this pattern from 1995/6 to 1997/8. The average fruit size of Royal Gala apples was bigger in the EFS than in the two sites in the Western Cape.

XXV International Horticultural Congress, Part 9: Computers and Automation, Electronic Information in Horticulture

E. Grebeye, O. Berg

‘Royal Gala’, winter chilling, reproductive bud, cell number

https://doi.org/10.17660/ActaHortic.2000.519.10