GOLSOOMEH AZIZI1, ASIEH SIAH-MARGUEE1, LEILA ALIMORADI1, ATEFEH KESHAVARZI2
1Ferdowsi University of Mashhad, Department of Agronomy, Iran
2Gorgan University, Faculty of Soil Science, Soil Science, Iran
Allelopathy refers to the beneficial or harmful effects of one plant on another plant through the release of chemicals from plant parts by leaching, root exudation, volatilisation, residue decomposition and other processes in both natural and agricultural systems. Allelochemical concentrations in the producer plant may also vary over time and is produced in the plant tissue.
In order to study the effects of different organ extracts of fenugreek (Trigonella gracum) on germination of some crops and weeds an experiment was conducted as a completely randomised design with 3 replications at the Ferdowsi University of Mashhad, Iran. Factors included 4 crops: soybean (Glysine max), sesame (Sesamum indicum) , pigweed (Amaranthus retroflexus) and velvetleaf (Abotilon teophrasti) and the extract of different Fenugreek organs (leaf, stem, seed, pod and total organs were applied at 4 levels: check, 4, 8, 32 and 64 g powder l-1 distilled water.
The results showed that the reactions of the crops and the weeds depended on the concentrations of the different organ extracts. Fenugreek extract not only reduced seedling growth of different species, but also inhibited seed germination. Negative and significant correlation was observed between the germination percentage and different concentrations of Fenugreek organs. A minimum regression slope could be obtained for the stem extract. Root and shoot length showed also a negative and significant correlation with the Fenugreek extract concentrations for all crops except for soybean. In general, velvetleaf was the most sensitive for fenugreek allelochemical. Alternatively, application of allelopathic compounds before, together, or after the application of synthetic herbicides could increase the overall effect of both materials. In this way, application rates of synthetic herbicides could be reduced.
Keywords: Allelopathy, fenugreek, Trigonella gracum, soybean, Glysine max, pigweed, Amaranthus retroflexus, sesame, Sesamus indicum, velvetleaf, Abotilon teophrasti