Abstract:
Barley [Hordeum vulgare (L.) Koch.] contains water soluble allelochemicals that inhibit the germination and growth of other species. This characteristic could be used in weed management programs. Greenhouse and laboratory experiments were conducted to determine the effects on wild barley (H. spontaneum Koch.) germination and seedling growth of preceding crops, (ii) fresh Barley residue incorporation, and (iii) Barley leaf, stem, flower and root water extract concentrations. Growth of wild barley, as indicated by plant height and weight, was significantly reduced when grown in soil previously cropped to Barley compared with that cropped to wild barley. Soil incorporation off fresh Barley roots and both roots and shoots reduced wild barley germination, plant height and weight when compared with a no-residue control. In bioassays, Barley extracts reduced wild barley hypocotyl length, hypocotyl weight, radicle weight, seed germination, and radicle length by as much as 44, 578, 61, 686 and 79 %, respectively, when compared with water control. Increasing the water extract concentrations from 4 to 20 g per 100 ml of water of all Barley parts significantly increased the inhibition of wild barley germination, seedling length and weight. Based on 8-day-old wild barley radicle length, averaged across all extract concentrations, the degree of toxicity of different Barley plant parts can be ranked in the following order of inhibition: leaves > flowers > mixture of all plant parts > stems > roots.
Page(s):
99-112
DOI:
DOI not available
Published:
Journal: Pakistan Journal of Weed Science Research, Volume: 13, Issue: 1--2, Year: 2007