International Trials of Acacia and Prosopis: Overview of results

bullet1 Burkina Faso
bullet2 Site: Gonsť

bullet3 Trial 10: Species and provenance trial of Acacia nilotica, A. seyal and A. tortilis

This trial was made up of 12 provenances, four of each of the species Acacia nilotica, A. seyal and A. tortilis. The provenances were mainly from Burkina Faso, but included three exotic provenances from Senegal, India and Sudan. The trial was established with a spacing of 4  x 4 metres in 1988 and assessed after 1, 5 and 10 years in 1989, 1993 and 1999, and different growth parameters were measured and subjected to analyses of variance and multivariate analyses.

The fastest growing provenances had an increment rate of 0.5 m2 ha-1 y-1, corresponding to a dry weight production of 1.6 t ha-1 y-1. The best provenances of each species had comparable growth rates. The species differed with respect to height, crown area and number of stems, A. seyal being the most tree-like and A. tortilis the most bushy, whereas A. nilotica was intermediate. In the multivariate analyses, A. seyal appeared very distinctly different from the other species.

In A. nilotica and A. tortilis, there were several significant differences between the provenances, but within the four provenances of A. seyal (all from Burkina Faso) there were no significant differences.

The genetic correlations between identical variables from the 1993 and 1999 measurements were high, but low between variables from 1989 and the other assessments. A test for new information revealed that there had been significant changes in the relative growth of the trees between 1993 and 1999, but that this was an accentuation of the differences in growth rather than a change in the rank between provenances.