Question

The phenomenon of photoperiodism was first discovered by ............ in the "Maryland mammoth" variety of .................

• A. Garner and Allard, tobacco
• B. Went, tobacco
• C. Garner and Allard, cocklebur
• D. Knott, cocklebur

Answer 1

The correct option is A Garner and Allard, tobacco

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 Gamer and Allard (1920) in 'Maryland mammoth' a variety of Tobacco.

Long Day Plants (LDP) flower when they receive long photoperiods or light hours which are above a critical length, e.g., henbane (Hyoscyamus Nget), wheat oat sugar beet, spinach (Spinacia oleracea), radish, barley, larkspur, lettuce.

So the correct answer is 'Garner and Allard, tobacco'.