Treatments that Enhance Flowering in the Post-inductive Period of a Short-day Plant, Chenopodium rubrum L.

Flowering was promoted in young plants of Chenopodium rubrum L. by application of growth inhibitors such as 5-fluorodeoxyuridine (FUDR) and (2-chloroethyl) trimethylammonium chloride (CCC), growth substances (indol-3yl-acetic acid, IAA), by the removal of roots and by drought. All the treatments were effective only during the post-inductive period and at the threshold level of photoperiodic induction. The response of plants was strictly time-dependent. The experimental data indicate that the stimulation of flowering is usually accompanied by inhibition of leaf initiation and growth. The treatments probably produced variation in the quantitative expression of flowering by causing a shift in emphasis in the development of leaf and bud primordia at the shoot apex. The dynamic analysis of differentiation of the shoot apex indicates a correlation between the morphological stage of the shoot apex and its responsiveness to the treatments.