The effects of various pretreatments on the germination of important leguminous shrub-tree species of the Sultanate of Oman

Abstract

Germination experiments were carried out in the laboratory to determine methods to improve the germination of four important and usefull leguminous species of Oman with impermeable hard seed-coats. Six different treatments were tried to break the coat imposed physical dormancy while untreated seeds were used as control. Out of the six treatments, manual scarification by coarse sand paper and immersion in concentrated sulphuric acid for 45 minutes enhanced the germination substantially in all four species. Seeds boiled in water for 20 minutes and mechanically scarified by coarse dune sand for 10 hours also improved the germination in all four species. Seeds left to cool in boiled water for 24 hours showed a slight increase in germination in all species. Exposure to dry heat at 60°C and 80°C for more than 6 hours reduced the germination in all four species. The species which showed the most improvement overall was Prosopis cineraria, which initially exhibited the highest dormancy.