Enhancement of corm and cormel production in gladiolus ( Gladiolus spp.)

Abstract The gladiolus ( Gladiolus spp.) industry is based on its flower and also its corm production. However, commercial cultivation is limited by the low multiplication rate of corms. This field study was conducted over 2 consecutive years (2006–07) to explore the possibility of increasing propagation rates by using half corms in comparison with whole corms along with various leaf and flower spike clippings. It involved a factorial combination of three varieties of gladiolus (viz. ‘Traderhorn’, ‘White friendship’, and ‘Peter pears’) and five treatments in a split‐plot design and with 3‐fold replication. The treatment of clipping three leaves with the flower spike, exhibited the best response in both years in all three varieties, producing the highest mean collective total weight of corms and cormels (136.59 g/plant). This production was 20.16% higher than in the untreated control. The advantage of this treatment was also apparent from the increase in the mean number of corms (27.86%) and cormels (17.47%) per plant. Comparison of the variety means shows that the variety ‘Peter pears’ yielded a significantly higher weight of single corm (62.35 g/plant), total corms (90.57 g/plant), and total corm+cormel weight (121.07 g/plant) than either of the other two varieties. On a unit stock basis, the yield of new corms was economically increased by planting half corms instead of whole corms, the increase being 64% in ‘Traderhorn’, 36% in ‘White friendship’, and 37% in ‘Peter pears’. All corms and cormels were graded into large and small sized corms on the basis of their diameter when categorised according to the North American Gladiolus Council. It is concluded that corm and cormel production can be maximised by the clipping of three leaves along with the flower spike, and that rapid propagation of new planting material can be successfully and economically achieved by using half corms instead of whole corms.