M. Makkizadeh Tafti; R. Farhoudi; M. Rastifar
Abstract
With regard to the importance of Melissa officinalis L. as a medicinal plant and abundance of saline soil and water in the country, the current research was conducted to study the effect of osmopriming on seed germination of Melissa officinalis under salinity stress in two separate experiments. The aim ...
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With regard to the importance of Melissa officinalis L. as a medicinal plant and abundance of saline soil and water in the country, the current research was conducted to study the effect of osmopriming on seed germination of Melissa officinalis under salinity stress in two separate experiments. The aim of the first experiment was to determine the best osmopriming conditions for seeds of Melissa officinalis carried out in a completely randomized design. The treatments were combination of osmotic potential of polyethylene glycol (PEG) with four levels (-4, -8, -12 and -16 bar), duration of priming with three levels (3, 5 and 7 day) and temperature of priming with two levels (25 and 30/20oC). The results showed significant differences among osmopriming treatments with regard to the germination percentage, germination velocity and radicle length. Mean comparisons showed that osmotic potential treatment of -16 bars in 5 days and 25oC significantly increased the germination percentage and germination velocity compared with other treatments. The aim of the second experiment was to study the effect of osmopriming on seed germination of Melissa officinalis under salinity stress based upon a factorial experiment in a completely randomized design with three replications. The treatments were water salinity (control, 4, 8 and 12 dS/m) and type of seeds (control and primed seeds). The results indicated that primed seeds in all salinity levels had higher germination percentage, germination velocity and radicle length compared to non-primed seeds. According to the results, the interaction effect of salinity and seed treatments was significant with regard to the germination percentage, germination velocity and radicle length.
M. Makkizadeh Tafti; R. Farhoudi; M. Rabiee; M. Rasifar
Abstract
Nowadays, in response to the consequences of herbicide application and gradual reduction of farm crops, suitable biological methods have been identified to control the weeds. This research was conducted to evaluate the allelopathic effect of harmel (Peganum Harmala L.) on seed germination of oat (Avena ...
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Nowadays, in response to the consequences of herbicide application and gradual reduction of farm crops, suitable biological methods have been identified to control the weeds. This research was conducted to evaluate the allelopathic effect of harmel (Peganum Harmala L.) on seed germination of oat (Avena fatua L.), fat hen (Chenopodium album L.) and pig weed (Amaranthus retroflexus L.) in laboratory and greenhouse conditions using hydroalcoholic extracts of harmel dried fruit powder. The treatments were 0.1, 0.25, 0.5, 1, 2.5 and 5% extract of harmel and distilled water (control). Laboratory results indicated that germination percentage and radicle and plumule lengths of weed species were significantly reduced by different harmel extracts in comparison with control. According to the results of greenhouse experiments, germination percentage, fresh and dry weight and height of weed species were significantly reduced by using hydroalcoholic extracts. Greenhouse results also showed that seed germination percentage of Chenopodium album, Amaranthus retroflexus and Avena fatua at concentration of 1% was reduced 60%, 50% and 40% respectively in comparison with control. Our results showed that harmel extract had strong allelopathic effects and inhibited seed germination of weeds recommended in production of natural herbicides.
M. Makkizadeh Tafti; M. Salimi; R. Farhoudi
Volume 24, Issue 4 , February 2009, , Pages 463-471
Abstract
The allelopathic effects of rue (Ruta graveolens L.) were evaluated on seed germination of velvet flower (Amaranthus retroflexus), flixweed (Descurainia Sophia) and purslane (Portulaca oleracea) in laboratory using the aqueous extracts of dried powdered of rue leaves. The treatments were 0.5, 1, 2.5, ...
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The allelopathic effects of rue (Ruta graveolens L.) were evaluated on seed germination of velvet flower (Amaranthus retroflexus), flixweed (Descurainia Sophia) and purslane (Portulaca oleracea) in laboratory using the aqueous extracts of dried powdered of rue leaves. The treatments were 0.5, 1, 2.5, 5, 10 and 15% extract of Ruta graveolens and distilled water (control). According to the results, extracts significantly inhibited seed germination of weed species and the degree of inhibition increased with increasing concentration of extracts. Germination of Amaranthus retroflexus seeds was inhibited at concentrations greater than 5%. In addition, radicle and plumule lengths of Amaranthus retroflexus were significantly reduced at 1% compared to the distilled water. Results indicated germination percentage, germination rate and radicle and plumule lengths of Portulaca oleracea were significantly reduced by the extracts compared to the distilled water. Results confirmgermination of Descurainia sophia seeds was inhibited at concentrations greater than 2.5%. Accordingly germination rate and radicle lengths of Descurainia sophia were significantly reduced by the extracts compared to the distilled water. Therefore, extract of rue might be useful as natural herbicides and might also contain numerous growth inhibitors that could be used for the development of biological herbicides.
