Cytokinins and Gibberellins Stimulate the Flowering and Post-Harvest Longevity of Flowers and Leaves of Calla Lilies (Zantedeschia Spreng.) with Colourful Inflorescence Spathes

Since the 1990s, the world has seen an increased interest in Zantedeschia with colourful inflorescence spathes. In Poland, its cultivation began much later. The reasons for this phenomenon can be traced to the high price of rhizomes reproduced in the United States of America, the Netherlands, New Zealand and Kenya. The area of reproductive plantations is increasing every year, but this does not affect the decrease in the price of rhizomes, which is the main reason that only a few producers are cultivating Zantedeschia cultivars in Poland. Producers offer rhizomes in various sizes, with flowering expected only from the largest ones. However, the yield of cut flowers that can be obtained from them is often not very satisfactory and is not compensated by the price that can be obtained from the sale of the flowers. It is the low yield of cut flowers that is the main problem in the cultivation of Zantedeschia cultivars, hence research conducted worldwide focuses on the use of growth regulators from the group of cytokinins (CKs) and gibberellins (GAs) in the cultivation of Zantedeschia with colourful inflorescence spathes. The post-harvest life of flowers and leaves of cultivated Zantedeschia cultivars is also an important problem. This review presents the results of research conducted over the years to improve the flowering and post-harvest life of the flowers and leaves of Zantedeschia with colourful inflorescence spathes.