Effects of Cuttings Length and Substrate on Cutting Parameters for the Domestication of Stereospermum kunthianum in the Sudano-Guinean Zone of Chad

The aim of this work was to develop the possibilities of domesticating Stereospermum kunthianum. Cuttings based on the length of the cuttings and the types of substrates were used to achieve this objective. The lengths L1 = 10 cm (BL1), L2 = 15 cm (BL2) and L3 = 20 cm (BL3) and the substrates black earth, sawdust, fine sand and homogeneous mixtures (1/1) black earth/sawdust (1/1) and fine sand/sawdust (1/1) were tested. The rates of rooting and budburst of the cuttings, and the average number of roots and leaves per cutting were determined. The results show that rooting rates were higher in BL2 (15 cm) in homogeneous mixtures and in black earth/wood sawdust (67.4 ± 0.10%). The rate of budburst was high in the homogeneous mixture of fine sand and wood shavings for BL3 (29.61 ± 0.09%). The average number of roots formed was high in the homogeneous black earth/wood shavings mixture (16.03 ± 2.16). The highest average number of leaves formed was in the black earth substrate (11.09 ± 0.56). The fine sand substrate recorded the highest mortality rate (20.02 ± 2.61%) with BL1. The BL2 cutting length and the equi-volumic mixtures of substrates improve the possibility of domesticating Stereospermum kunthianum.