Inhibition of flowering in Chinese cabbage by applying heat and growth retardants to transplants

Abstract

A procedure was developed to reduce premature bolting and flowering in Chinese cabbage grown in the field during the winter. This involved (a) the use of geothermic water as an inexpensive heat source for heating the transplants in the nursery; (b) application of the growth retardants daminozide (Alar) and paclobutrazol (PP333) to the heated plants before removing them to the field; and (c) application of daminozide to the plants in the field. This procedure markedly reduced stem elongation and the length of the internal stem in relation to the head without affecting the size of the head. Furthermore, application of daminozide in the field minimized the severity of tipburn, a common physiological disorder in Chinese cabbage fields. The result of such treatment was the production of high-quality Chinese cabbage heads which otherwise are unobtainable during the winter.