THE PRODUCTION OF HEALTHY STRAWBERRY PLANTS

The prevention of disease by the use of young strawberry plants whose health is strictly controlled is imperatively required both for the culture under shelter and in the open air.
Several parasites and diseases can no longer be eliminated completely after planting: Tarsonemes, leaf and stem nematodes, Verticillium, Phytophthora, Viroses.
The damage caused by these parasites or diseases may be important:

• decrease in yield (25–40% for viroses);

• contamination of the soil for several years on.

The prevention of disease requires healthy mother plants and a severe visual control of the multiplication fields.
The Station of Fruit and Vegetable Cultures of Grand-Manil works as follows:

Depart-Material: each mother plant undergoes:

• a warm water treatment (7 minutes 46.1°C) against Tarsonemes and nematodes.

• Indexing with mechanical transmission on Chenopodium quinoa and by graftings of folioles (3 grafts by indicator) on 2 clones of Fragariavesca (McGrew’s clone and East-Malling clone) to detect viroses.

• In case of necessity, a cleansing by thermotherapy, followed by index techniques.

• If necessary, a control to detect Verticillium by microscopic cut in the petiole and Phytophthora by Molot’s technique.

Basis material (Super elite or Elite): this material is issued in isolated fields which are regularly visited.
Tests are made by soundings and whenever there is any doubt.

In Belgium, the production of "controlled plants" exists, but is not compulsory.

Symposium on Strawberry under Protection

P. Boxus

https://doi.org/10.17660/ActaHortic.1973.30.22