Runner formation on strawberry plants in autumn and winter

Summary In order to test strawberry selections for viruses, for which runners are necessary, the second writer tried, in connection with experiments carried out by Borthwick and Parker (1), to produce runners in the autumn and winter of 1952–53 by interrupting the dark period, however, without any result. Experiments carried out in 1953–54 have shown that too low a temperature was the cause of this failure, for runner formation in autumn and winter is dependent not only on day length but also on temperature.In the course of our 1953–54 experiments we found that in 1937 Darrow (2) had already made mention of the interrelation of temperature and day length in runner formation. However, it is not likely that sufficient runner formation would have taken place, had we applied his findings.