Letter | Published:

Onions and Vernalization



IN connexion with work on the induction of flowering, an attempt was made to vernalize onion. It is known that autumn-sown onions occasionally become thick-necked in the following summer. In February of this year, onion seed of the varieties James Long Keeping and Ailsa Craig was germinated at 23°C. Those seeds in which the radicles were just emerging (one day after soaking) were subjected to a temperature of 2°C. for three weeks and seven-eight weeks and were planted out in seed trays ; they were kept in a greenhouse until mid-March and the end of April respectively and all transplanted in the open air on May 7, together with untreated controls germinated on February 25, and also on April 1 in the case of Ailsa Craig.

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