Trials Inllle Introduction of Acacias in the Arid Zone of Rajasthan I-seed Studies

Seeds of 45 exotic Acacia species including different provenance of some of the species were tested for their seed characteristics and germination behaviour. The studies have revealed that most of the species have a prolonged germination periods, the average being 75 days. Germination per cent varied from 2 to 92 per cent. For the purposes of seed treatment, to hasten germination and reduce germination period, the species were grouped into 3 categories, namely, species of low, medium and high GEI/GC ratio. Of all the Acacia species, 39 species exhibited a medium and high GEI/GC ratio thereby indicating necessity of some pre-seed treatment to reduce their total germination period. The species were further grouped on the basis of the percentage of survival of seedlings in the nursery. Thirteen species were rated as 'hardy', 7 as 'medium' and 25 as 'poor'. Of these, the hardy ones are suitable for extensive field trials throughout the region, whereas species belonging to the other two ratings, should in the first instance be given trial in rainfall regions of 375 mm and above.