Abstract:
The number of contractile roots formed in gladioli was inversely related to the depth of the planted corm.
Below a certain depth, no contractile roots were produced.
Large corms did not produce contractile roots at any planting depth but split into two or more small corms.
Depth perception is a function of two independent mechanisms, viz. temperature fluctuation in the root initiation zone and the amount of light perceived mainly by the upper sheath leaf, the length of which varies with planting depth.
Various growth substances applied to the leaves or corms did not induce contractile roots in dark grown plants but roots were induced in both small and large corms in constant temperatures by auxin and gibberellic acid.
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