Air layering of three agroforestry species in the Guinean savannah highlands of Adamawa in Cameroon

Abstract

Ximenia americana, Vitex doniana and Lophira lanceolata are species prized by the populations of the Guinean savannah highlands of Cameroon. They are unfortunately still in the wild where they are subjected to various pressures. From the perspective of the conservation and enhancement of local biodiversity, their domestication appears necessary. The objective of the work is to study the vegetative propagation by air layering of these fruit trees. The experimental device used is a split-split-plot with three repetitions. Species represents the main treatment; the substrates constitute the secondary treatment while the covering of the layers with aluminum foil represents the tertiary treatment. The experimental unit was 30 layers. The rooting rate of layers varies significantly (0.000<0.001) from 48.88±1.89% in Ximenia americana to 81.38±2.08% in Lophira lanceolata. Sphagnum was the best substrate with 69.63±1.38% against 61.66±1.54% for the black soil-sawdust mixture. The analysis of variance reveals a significant difference for the substrates (0.0025<0.01). Covering the layers with aluminum foil presented a rate of 69.44±2.15% while the uncovered layers presented 61.85±1.54%, the analysis of variance shows a significant difference (0,0031<0.01). Lophira lanceolata exhibited the best air layering ability; the rooted layers were weaned and acclimatized for two months before being transferred to the field. During this process 19% and 52% respectively of the layers of Vitex doniana and Ximenia americana flowered. This inexpensive technique is an essential step in the process of their domestication.