Effect of Seed Coating Methods on Germination Speed of Onobrychis
sativa at Different Drought Stress Levels and Sowing Depths
Seed enhancement methods are applied to eliminate or decrease adverse environmental stresses
effects and increase seed germination rate and vigor of rangeland plants. The aim of this study was to assess
different methods of seed coating effects on germination speed of Onobrychis sativa at different sowing
depths and soil moisture levels. The experiment was conducted at growth chamber to apply a better control
on environmental factors. So the intact effects of different seed coating treatments were better distinguished
by eliminating the interfering environmental factors. The treatments were set up in factorial arrangement
based on a Randomized Complete Block (RCB) design with three replications. Factor A: treatment of
drought stress treatment at three levels of 9%, 14% and 21% of soil moisture content and factor B: sowing
depths of range plants at two levels of leaving the on soil surface and sowing the seed in the soil at 3 times of
its thickness and finally factor C: seed coating material with four levels of control (no coating), organic
coating, hydro gel coating and mineral coating. Parameter such as germination speed parameter were
measured. Results showed that range species seeds coated with different coating materials created in this
experiment, significantly performed better germination speed in both normal and drought stressed situations