Cultural experiment of reddish-purple tuberose (Polianthes) under different climate conditions in Taiwan

The cultivation of reddish-purple tuberose '77A05' in open fields was carried out at four different altitudes in Taiwan and the site selection for commercial production for cut flowers in colored tuberose was discussed. Days to flowering from planting at Pingtung (altitude=25m) and Tapan (1,200m) were 80.3 and 89.5, respectively. The higher altitude, the longer the flower stalk. Floret size increased by increasing the altitude, but number of florets was not affected. Flowers cultivated at Chiayi (75m) and Pingtung were pale purple but reddish-purple at Hsinshe (500m) and Tapan. The anthocyanin content of the flowers at Hsinshe and Tapan was approximately two and three times higher than that at Pingtung, respectively. The site selection for cultivation of colored tuberose when anthocyanin is the primary pigment must be carefully considered. High elevation areas in Taiwan seem to be suitable for the cultivation of anthocyanin-containing tuberoses.