Abstract:
P. juliflora is an evergreen exotic poisonous weed species and its alarming rate of invasiveness
had affecting the livelihood of pastoral communities in Amibara rangeland of Afar Region. This
study aims to investigate effects of P. juliflora on soil seedbank flora and its allelopathic
potential on seed germination, growth and biomass production of Cenchrus cillaris, paspalidium
desertorum and Litonia nutans. A total of 20 Soil samples were collected from five sites
measuring sample quadrats of (20m X 20m) area and soil samples from each quadrat were taken
from 5 sub-quadrats/m2, one from center and four from corners, at two depth (0-3cm and 3-10
cm). A total of 38 herbaceous species /m2 that belongs to 16 families were emerged in upper and
lower layer soil seedbank samples. The highest diversity of (3.17, 3.15 and 3.04) were recorded
in Awash-arba, Alaydagi and Kurkura. While, least diversity of (2.75and 2.77) were recorded in
Melka-Werer and Sarkamo. Jaccard’s coefficient similarity of (55.6%) at the upper soil
seedbank were in Melka-werer and Sarkamo. while lowest similarity of (31.8%) were recorded
at lower layer soil seedbanks in Sarkamo and Kurkura. Ten grams of each leaf, bark and root
aqueous extract prepared at (0%, 1%, 2.5%, 5% and 10%) concentrations used for germination
bioassay and pot experiment. Seed germination of P.desertorum was significantly inhibited by
leaf extract at (42.13). C.cillaris seed germination was significantly suppressed at (2.5%, 5%
and 10%) as compared with control. Plumule length (cm) of C. cillaris was highly significantly
inhibited at (10%) when compared to control. Radical length of C. Cillaris, P. desertorum and L.
nutans were exhibited highly significant inhibition at (5% and10%) when compared to control.
Bark exposed highly significant effect on fresh shoot weight of C. cillaris and L. nutans at (10%)
and P. desertorum at (5% and 10%), while least significant exhibited at (1%) as compared to
control. Bark exposed significant inhibition on dry shoot weight of L. nutans at (9.87). Root
exhibited least significant inhibition on dry shoot weight of C. cillaris at (14.91). Bark showed
significant reduction on fresh root weight of L.nutans at (6.03). Therefore, out controlling
invasion of p. juliflora causing negative impacts on plant diversity, ecosystem services and
forage grass species.
