Abstract:
Wheat (Triticum aestivum) growth and yield are depressed by physical and chemical interference of weeds. Recently, wild barley (Hordeum spontaneum) population has increased in wheat fields of many provinces of Iran. Since, little is known about the allelopathic effects of wild barley residues in soil, greenhouse studies were conducted to examine the effects of soil amended residues of wild barley at 0, 0.2, 0.4, 0.8, and 1.6 kg m-3, and its root exudates on growth and yield of wheat. There were no significant differences in wheat seedling height and FW when exposed
to 0.2 and 0.4 kg m-3 , whereas, the two high residue levels, i. e., 0.8 and 1.6 kg m-3 significantly reduced these parameters. Two high residue levels also significantly reduced seedling and mature plant height fresh and dry weights, and yield of wheat. Root exudates that released from wild barley seedlings into the soil, did not affect wheat seedling height, whereas, those released from tillers significantly decreased seedlings and mature plants heights, FW and DW and yield of wheat.
Machine summary:
"Phytotoxicity effects of soil amended residues of wild barley (Hordeum spontaneum Koch) on growth and yield of wheat (Triticum aestivum L.
Key words: Allelopathy; Soil amended residues; Wild barley; Hordeum spontaneum; Wheat growth; yield 1.
H. spontaneum has its center of diversity in the Fertile Crescent of Middle East where it colonizes a wide range of habitats from high rainfall to desert, from cool to hot areas and from sub-sea levels to altitudes in excess of 1700 meter (Harlan and Zohary, 1966) Our previous laboratory studies showed the allelopathic effects of aqueous extracts of wild barley residue on germination and seedling growth of wheat (Hamidi et al.
Effects of different contents of soil amended residues of wild barley on wheat growth stages of seedling (A, B and C) and maturity (D, E and F), and yield (G) 3.
2. Experiment 2 Figure 2 shows the phytotoxicity effects of wild barley roots that obtained by cutting of plants from the soil surface at 2 growth stages on wheat growth and yield.
Effects of wild barley root exudates on wheat growth stages of seedling (A, B and C) and maturity (D, E and F); and yield (G) With regard to the fact that the activity and availability of allelochemicals in the soil depend on donor plant density (Rice, 1984), it would be expected that larger population densities of wild barley that usually occur in wheat fields, if its control does not take place, may be more effective to wheat growth and yield reductions than lower ones."