Growth and rooting of Solanecio mannii : comparison of seedlings and air layers on a 24-month trial in East Africa
Vegetative propagation of trees remains understudied in Africa. Such methods however provide potential for producing trees and shrubs with high social and economic value. Air layering is one of these techniques and can be used in Uganda for the domestication of underutilized multipurpose trees. The main purposes of this trial were to compare the growth rates of 30 Solanecio mannii plants grown from seed and 30 plants grown from air layering, and to observe the main morphological differences that affected the growth and root system of those 60 plants. This 24-month preliminary and prospective trial was conducted to compare the growth characteristics of seedlings and air layers, by measuring their height, diameter, precocity to flower and fruit, and their root system quality. Air layers were stronger, quickly reaching maturity but showing weakness in their root systems, while seedlings seemingly smaller and slower showed more stability with a well-structured root system. Air layering could be used to reproduce desirable genotypes. Due to their unbalanced root system observed in the field after two years, the air layers, once transplanted into a nursery, should be propagated by cuttings or grafting only.