Plants which require an exposure to light for a period greater than critical day length are

Options

A. long day plants
B. short day plants
C. long-short day plants
D. short-long day plants

Answer

A

Explanation

The effect of photoperiods or daily duration of light hours (and dark periods) on the growth and development of plants, especially flowering, is called photoperiodism. Photoperiodism was first studied by Garner and Allard (1920) in 'Maryland mammoth' a variety of Tobacco. Long Day Plants (LDPs) flower when they receive long photoperiods or light hours which are above a crictical length, e.g., henbane (Hyoscyamus niger) wheat, oat, sugar beet, spinach (Spinancea oleracea), raish, barly, larkspur, lettuce.