EFFECT OF TEMPERATURE AND PHOTOPERIOD ON FLOWER BUD INITIATION IN EVERBEARING TYPE STRAWBERRY CULTIVARS

Flower bud initiation at apices of axillary branches of four everbeari ng strawberry cultivars grown in growth chambers held at 20 degrees, 2 5 degrees, 30 degrees C and photoperiods of 4, 8, 12 and 16 hr was stu died. 1. Almost 100% of the apices of axillary branches differentiated flower buds on all cultivars under all growing conditions. 2. In all four cultivars, a high frequency of flower buds aborted before anthesi s occurred at 30 degrees C, whereas a low frequency of aborted flower buds occurred at 20 degrees and 25 degrees C. 3. The number of leaves which formed on the axillary branches (branch leaves, BL) before flowe r buds were differentiated was counted. The number of BL was not unifo rm on branches, ranging from 0 to 6. At 20 degrees C, BL averaged 2, w hereas, at 25 degrees and 30 degrees C, it was 3. However, the effect of photoperiod and cultivar on BL was not clear. The differing intensi ty of recurrent flowering trait in these everbearing strawberry cultiv ars is the result of varying degrees of flower bud abortion which is a ttributed to the competition between the terminal inflorescence and th e newly developing lateral branch in the axil of the leaf just below i t.