Jm. Dole, INTERACTION OF SHOOT EMERGENCE DATE AND LONG DAYS AFTER CONTROLLED-TEMPERATURE FORCING OF NELLIE WHITE EASTER LILIES, Journal of the American Society for Horticultural Science, 118(6), 1993, pp. 741-746
'Nellie White' Easter lily bulbs (Lilium longiflorum Thunb.) were give
n 6 weeks of 5.5C, placed in the greenhouse, and divided into groups b
ased on number of days to emergence: 0 to 6, 7 to 13, 14 to 20, or 21
to 27 days. At emergence, the shoots received O, 1, 2, or 3 weeks of l
ong days (LDs). The experiment was repeated for 3 consecutive years. L
ate-emerging plants had fewer days from emergence to visible bud and a
nthesis than early-emerging plants. Consequently, late-emerging plants
flowered within 3 to 11 days of early emerging plants despite 16 to 2
2 days difference in emergence time. Late-emerging plants were tallest
, while plants emerging in the second week had the most leaves. Flower
count was not influenced by emergence date in Year 1. In Year 2, Bowe
r count decreased curvilinearly with later emergence. In Year 3, Bower
count was highest in plants emerging in the second week and lowest in
the last week. Increasing LDs decreased the number of days from emerg
ence to visible bud and anthesis but increased plant height. LDs did n
ot affect leaf count in any year or newer count in Years 1 and 2. In Y
ear 3, Bower count increased with increasing weeks of LDs. LD x emerge
nce date interactions existed, but varied from year to year.