Some aspects of mineral nutrition and flowering

In mustard N deficiency accelerated flower initiation and particularly flower bud development. Excess N delayed flowering but increased number of flowers. Of other elements Ca influenced flowering most.

Dill developed its flowers most rapidly with normal or high rates of N. N deficiency retarded flowering and decreased the number of inflorescenses.

In spinach N rate only slightly influenced flowering. N deficiency retarded flower budding by a few days.

Perilla crispa reacted most to N and P. Except where N was in excess (2N), the time required for appearance and development of flower buds was negatively correlated with the N concentration, while the number of flowers was positively correlated with it. P deficiency delayed flowering and decreased the number of flowers.

With Kalanchoë blossfeldiana N increased the number of flowers and accelerated flowering.

Mineral nutrition had only quantitative influences on the photoperiodic behaviour of the crops studied.

It was concluded that the effect of minerals on the flowering process of LD (mustard, dill and spinach) and SD plants (Perilla and Kalanchoë) was indirect, through their effect on synthesis of material for flower bud formation, on auxin production and hence on growth.