Effect of paclobutrazol and kinetins on the vegetative growth, root initiation and tuberization of Manihot esculenta crantz
Field experiment was conducted to investigate the effect of application paclobutrazol (PBZ) and Kinetin at different concentration rates on growth, root initiation and tuberization of cassava grown under rainfed conditions. The experiment was set up as a 2x3x2 factorial in a complete randomized design with 3 replications. The first factor was the PGRs (Paclobutrazol and Kinetin) application, the second factor was varieties (TME419, IKWOCAS-LOCAL and UMUCASS 36) with the levels and third factor was the concentration (0, 100 and 200ppm). The uniform 25cm cassava stem cuttings obtained from the National Root Crops Research Institute and Ndufu Alike, Ikwo were soaked in the plant growth regulators for 30mins and allowed to dry at the different concentrations before the cuttings were thereby planted on the field. The plot area was 5m2 (1x5m) with inter and intra plot spacing of 1x1m between plots. Manual weeding was employed. From the result, the PBZ application reduced plants height and number of leaves, but tend to increase stem diameter while Kenitin application improved plant height and number of leaves, number of root, harvest Index and root weight, but reduced stem diameter of cassava as compared to untreated control. Kinetin application at 200ppm increased the storage root yield and vegetative growth by 53.08% and 52.61% respectively while PBZ application increased the storage root weight by 46.92% and had no effect on the vegetative growth. We recommend treatment combinations for future study on the root initiation, tuberization and shooting formation.
Keywords: Paclobutrazol, kinetins, vegetative growth, root initiation, tuberization.