A Comparison of the Effectiveness of Chlormequat Chloride (CCC) Application and Terminal Apex Excision to Restrict Plant Height in Okra (Abelmoschus esculentus [L.] Moench.) and Optimize Yield

Abstract

Two methods for restricting plant height (CCC application and excision of the main shoot apex) were applied to okra cv. 'Boyiatiou' with the aim of assisting crop management and optimizing yield. Apex excision 26 or 40 days after transplantation (DAT) effectively restricted plant height, but either had no effect (40 DAT) or reduced the number of side shoots per plant (26 DAT). Moreover, although the length of side shoots increased after apex excision, the number of nodes per side shoot was not affected. Hence pod number and weight was less than in the control (untreated). CCC application (500 and 2000 ppm) reduced plant height due to a reduction in internode length; however, when applied at the time of transplantation (0 DAT) (both concentrations) or 26 DAT (2000 ppm) it also caused a reduction in node number on the main stem. CCC did not affect the number of side shoots or the number of nodes per shoot, and side shoot length decreased due to shorter internode lengths. The number and weight of pods per plant was reduced by 2000 ppm CCC irrespective of the time of application, but was not affected by 500 ppm CCC at 0 DAT (pod number) or 40 DAT (pod weight and number). We conclude that the application of 500 ppm CCC at 40 DAT may aid okra cultivation since it reduces overall plant size (height and diameter) without adversely affecting yield, and may thus assist crop management (e.g. easier hand-harvesting) and permit an increase in plant density.