Seed germination, seedling growth and biomass prediction on pre treated seeds of Acacia senegal

Abstract

Acacia species are characterized by a very hard and impermeable seed coat resulting to temporary dormancy and influences germination process. Therefore, the application of severe treatments of seeds is needed to break the dormancy and also speed up the process of germination. The study was achieved through germination trial experiment using different treatment methods in a nursery. The experiment was conducted on 1st Dec 2019, during dry season at Kenya Forestry Research Institute Lodwar Nursery. Seeds were collected from different part of Turkana County and provided by KEFRI to be planted in nursery for the study. An experiment was carried out to study the effect of seed pretreated on emergence of Acacia senegal, to determine seedling germination growth rate and biomass prediction. The pretreatments were; lukewarm water (water at room temperature of 20C plus hot water of 15C) and cold water (at room temperature). The seed soaked in lukewarm water for 12 h had the shortest time to germinate (2 days after sowing). Shortest time to 50% emergence (5 days after sowing) and shortest time to last observed emergence (8 days after sowing). The seed soaked in lukewarm water also produced the highest percentage emergence of 70%. This can be compared to the seed soaked with cold water. For seed soaked in cold water for 12 h of germination was moderate. It took moderate time to germinate (4 days after sowing) and also took moderate time to last observed (10 days after sowing). It took moderate time to attain 50% emergence (10 days after sowing). The seed soaked in cold water produced average of 50%. The study shows that seed without any pretreatment took longer time to germinate (6 days after sowing), longest time to last observed emergence (15 days after sowing). Seed without pretreatment did not attain 50% emergence. The study findings presented in biomass Table showed that the lowest root collar diameter of A. senegal seedling is 1 mm, and highest root collar diameter is 4.5 mm. Regression equation for seeds soaked in lukewarm water is 0.9818; cold water is 0.9412 and control 0.9158. The best regression equation was given by seeds soaked in lukewarm water. Based on the result of the study, pretreatment of A. senegal seeds with lukewarm water for 12 h before sowing in the nursery is encouraged.