Broomcorn allelopathic effect on germination and early growth stages of barley

Broomcorn is extensively cropped in Miyaneh region for traditional broom production and occasionally included in rotation with barley by local farmers. The research objective was clarifying of broomcorn allelopathic potential on barley germination and initial growth. Allelopathic properties of 2.5, 5, 7.5, and 10% of broomcorn roots and shoots aqueous extracts sampled 1, 2, 3, and 4 months after planting, also root exudates using equal compartment agar method and 5 and 10% of intact and burnt crop residues aqueous extract on barley germination and initial growth were evaluated. Also, 2.5, 5, 7.5, and 10% of 3-month broomcorn foliar extracts on barley seedlings growth was evaluated in greenhouse condition. Broomcorn root extracts was less allelopathic on barley seed germination, also 3-month foliar was the most allelopathic studied plant organs on seed germination and growth of barley. Also, broomcorn root exudates were more toxic on barley plumule than radicle. Residue burning decreased allelopathic effect of broomcorn residue up to 77%. Irrigating with broomcorn extracts had less allelopathic effects than direct bioassay on barley seedlings in laboratory. Considering remarkable allelopathic potential of broomcorn on barley, its residue management should be concerned in broomcorn-barley rotations.