THE PERFORMANCE OF SWEET CHERRY CULTIVARS AND CHERRY ROOTSTOCKS UNDER SOUTH AFRICAN CONDITIONS

The first cherry orchard was planted in 1860 near Cape Town, although the first cherry trees arrived in South Africa in 1652. Today the main cherry producing area is situated in the South African Highveld in the Eastern Free State where the first orchards were established in 1904. The cherry industry developed slowly and has expanded rapidly since 1950. About 95 percent of the bearing cherry trees are now found in this part of South Africa where about 120 000 trees have been established on 500 ha.

The cherry producing area in the Eastern Free State is situated at approximately 28°45′ latitude and 27°45′ longitude and 1650 meters above sea level.
This Highveld is part of the summer-rainfall area, with very dry winters and below zero temperatures during winter nights.
Nine hundred hours and more with air temperatures of 7°C and below are experienced in this area during May, June and July.

The average temperatures are: Maximum: 22°C; Minimum: 7°C; Average: 14,5°C; with an average of 8,5 sunshine hours per day.

The average rainfall is 756 mm per year with 82 percent during summer (October to March).

The most important problems of cherry cultivation are:

1. Heavy tree losses due to bacterial canker (Pseudomonas morsprunorum; P. syringae).

2. Finding cultivars to extend the picking season which only lasts five to six weeks.

3. Suitable rootstocks for local soil conditions which can be propagated easily and can help to control tree size.

Research to cope with these problems was started in 1971, when attention was given firstly to the importation of the best known sweet cherry cultivars and rootstocks for propagation under South African conditions; secondly to the establishment of virus tested plant material and thirdly to control programmes against bacterial canker.

International Workshop on Improvement of Sweet and Sour Cherry Varieties and Rootstocks

K.G. Zwahlen

https://doi.org/10.17660/ActaHortic.1985.169.17