Early Growth in Rice varieties in relation to their Duration and response to growth-substances

Abstract

A good deal of attention has been devoted in recent years to the inter-relations that exist in a number of crop plants between differences in the early growth and the subsequent growth behaviour of these plants. (Thimann and Lone, 1938; Sinnott, 1939; Van Overbeek, 1935; Kaiser and Albaum 1938). The last two workers were able to find a close relation in the case of oats, between the early growth and the-subsequent flowering behaviour. An early-flowering variety (Fulghum) was found to have in the early stages of growth a slower rate of root growth than a late-flowering type Black Norway. The two varieties differed also in their response to different concentrations of the growth-promoting substance B-indole acetic acid. The late-flowering type Black Norway showed a more rapid shoot growth when treated with concentrations of 002 mg./litre to 2-0 mg./ litre, while the early-flowering type Fulghum remained unaffected. A similar relation was observed in two other varieties of oats as well and the authors.concluded that if such a relation was found to be general, it could be made to serve as a valuable index of flowering time.