Performance of Acacia senegal (L.) Willd accessions for tree height at rocky rangelands of the Thar desert

Acacia senegal (L.) Willd, a multipurpose tree, is commonly found on the rocky sites and the sand dunes where annual rainfall is 200–350 mm. To identify fast growing genotypes, seeds of eleven accessions were collected from arid and semi-arid areas of Rajasthan. The germplasm was evaluated at the nursery and the plantation was established at the rocky rangeland of the Range Management area, Central Arid Zone Research Institute, Bhopalgarh, during 1985. The accessions differed significantly for tree height over all the six growth years. Acc. No. 364 from Bar (Ajmer) and Acc. No. 359 from Jhurli (Jodhpur) were top performers from the second year onwards. There was no gum exudation in any of the plants. The overall survival percentage of the population over the years studied decreased from 97% in first year to 93, 90, 87, 84 and 79% during subsequent years. Mean tree height over the six years was 33•8, 50•0, 55•9, 59•5, 70•8 and 90•4 cm, respectively. The juvenile-mature relationship showed that selection in the nursery is effective to isolate fast growing genotypes.