Abstract:
Among several alien weeds Water Hyacinth (Eichhornia Crassipes)(known as Emboch in
Ethiopia)is ranked as one of the world’s worst invasive weeds due to its ability to rapidly
cover the entire water surface and cause problems for millions of users of water resources.
This weed was introduced in Ethiopia since 1964and ever since it becomes a major problem.
This study focuses on the estimation of water losses by transpiration from root-clipped, leaf clipped plants (treatments) and makes comparison with those of the normal plants (control).
In addition, crop factors and plant coefficients were also compared. The study was done over
17 days and used water balance method to estimate evapotranspiration from the plants in
relation to pan evaporation. The result showed that the evapotranspiration by normal plants
(Control group), plants with clipped roots (CR), and plants with clipped leaves (CL) were
2.25L/d (7.96 mm/d), 0.85L/d(3.01 mm/d), and 1.51 L/d (5.34 mm/d), respectively, compared
to mean daily pan evaporation of0.88 L/d (3.11 mm/d). The transpiration rates from the
normal and leaf-clipped plants were 1.37L/d (4.85 mm/d) and 0.72 L/d (2.55mm/d),
respectively. The root-clipped plants did not show any transpiration. Additionally, the value of
crop factors (Cp) calculated showed 1.09, 0.40 and 0.73 for C, RC and LC, respectively. The
crop coefficient (Kc) result showed 1.42, 0.54, and 0.95for C, RC and LC respectively.
ANOVA results of T, Cp showed significant differences between treatments and the control and
also between treatments. The conclusion drawn is that root-clipping has better effect than
clipping of leaves when it comes to reducing the rate of transpiration from the plant. It is
better to find other physical methods of ill-managing the plant rather than trying to remove
the entire plant from water bodies since it is too cumbersome.
