الملخص

The present research aimed to study the effects of lower plant residues of (Cladophora glomerata, Chara sp., and Ceratophyllum demersum) with three treatments of 0.5, 1%, and 1.5% as an allelopathic agent on the barley (Hordeum vulgare L.) germination, growth properties, chlorophyll content, and relative growth rate (RGR).  Statistically, a completely randomized design (CRD) was used with four replications, and Duncan’s test was applied to compare means. Results showed that using Chara sp. at a dose of 1.5% significantly (P≤0.05) increased shoot weight, number of spikes, and the total weight of seed, while spike length significantly increased at a 1% dose. Cladophora sp. at 1.5% dose significantly(P≤0.05) increased plant length, shoot weight, spike length, number of spikes, and the total weight of seed compared to the control plant. However, the flag leaf length was increased significantly (P≤0.05) at 1% treatment. Ceratophyllum demersum at 1% and 1.5 % doses (P≤0.05) causes increases in the total chlorophyll content, and chlorophyll a. The highest inhibition percentage was observed at a 1% dosage of Cladophora glomerata residues.