Abstract

Most of the trees introduced for the development of landscape agriculture in Kuwait are meant only for foliage and greenery purpose. Therefore, the study was initiated to introduce flowering trees of the genus cassia (Cassia fistula L. and Cassia nodosa Buch-Ham. ex Roxb.) to the landscape architecture of Kuwait and to break their seed dormancy. Three experiments were conducted on both species to determine the effect of various treatments such as surface sterilization, mechanical scarification, hot water, sulfuric acid, water soaking, growth regulators and acid scarification on seed germination. In all the experiments, daily observations were recorded for two months after sowing. For experiment 1, mechanical scarification resulted in better germination for heavy seeds of C. nodosa compared to unscarified seeds. For C. fistula, treatment T6 (HSH) was the best in germination (85%). Regarding experiment 2, T8 showed the highest germination ratio (18%) followed by T9 and T12 for C. nodosa. In C. fistula T18 was the best method for high germination (84%) followed by T16 with germination of 34%. In experiment 3, 20% germination was observed in T3 and T7 for C. nodosa followed by T1 with a germination of 17%. For C. fistulahighest germination (83%) was observed in T11 followed by T12 with germination of 77%.The study proved that seed treatments are necessary to overcome dormancy in cassia seeds. However, further experiments should also be conducted to draw a satisfactory conclusion regarding seed germination of C. nodosa and C. fistula since germination is influenced by various factors.

Key words: Cassia, dormancy, seed germination, surface sterilization, mechanical scarification, hot water, sulfuric acid, water soaking, growth regulators, acid scarification.