Y. Ijiro et R. Ogata, EFFECT OF AMBIENT-TEMPERATURE ON THE GROWTH AND DEVELOPMENT OF AMARYLLIS (HIPPEASTRUM-HYBRIDUM HORT.) BULBS, Engei Gakkai Zasshi, 66(3-4), 1997, pp. 575-579
How different day/night temperature affect the growth and development
of the vegetative and reproductive parts, including the bulbs of amary
llis (Hippeastrum hybridum) plants in growth chambers for two years wa
s investigated. One-year-old, 2-leafed seedlings were transferred to g
rowth chambers set at 17 degrees/12 degrees C(low, L plot), 24 degrees
/17 degrees C (middle, M plot) and 30 degrees/24 degrees C (high, H pl
ot) under natural daylength. 1. High temperatures (H plot) hastened th
e unfolding and elongation of leaves, and increased markedly the growt
h of mother bulb and daughter bulbs,but the plants did not flower. 2.
In plants exposed to low temperature (L plot), the leaves wore the slo
west of the three plots to unfold and elongate; the mother bulbs were
slow to enlarge but produced the most daughter bulbs. The temperature
favored floral development. 3. Middle temperature (M plot) educed inte
rmediate vegetative growth and the enlargement of mother and daughter
bulbs. This condition was optimum for flower stalk elongation and flow
ering. Thus, comparing the responses of amaryllis grown under low, mid
dle, and high day/night temperatures, high temperature favored promoti
on of mother bulb enlargement, but the moderate and low temperatures w
ere optimum for bulb and flower production.