Plant Growth and Development Question 70
70. Importance of day length in flowering of plants was first shown in
(a) lemna
(b) tobacco
(c) cotton
(d) petunia
Show Answer
Answer : b
Hints & Solutions
(b) Photoperiodism was first studied by Garner and Allard (1920). They observed that “Maryland Mammoth” variety of tobacco could be made to flower in summer by reducing the light hours with artificial darkening. It could be made to remain vegetative in winter by providing extra light.
