M. Dejam; R. Ataollahi; S. Sadat Khaleghi
Abstract
Worldwide, large amounts of herbicides are used for weed control. Problems due to the use of these herbicides have forced researchers to find more suitable methods for management of weeds. Some plants including Eucalyptus species have allelopathic properties that could be used in production of natural ...
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Worldwide, large amounts of herbicides are used for weed control. Problems due to the use of these herbicides have forced researchers to find more suitable methods for management of weeds. Some plants including Eucalyptus species have allelopathic properties that could be used in production of natural herbicides for weeds management. This investigation was performed in order to use Eucalyptus globulus Labill. leaf extracts to control Physalis alkekengi L. weed. The experiment included five types of solvent extracts consisting of aqueous, methanolic, ethyl acetate, acetonic and benzene and different concentrations of extracts at five levels (0, 1.25, 2.5, 5 and 10 gram per liter). Results showed that, in all solvent extracts, the inhibition level on germination and seedling growth increased by increasing the concentration of the extract. Among the extracts, methanolic and benzene extracts showed the highest allopathic effects, while aqueous and acetonic extracts showed the lowest one. According to the results, methanolic extract showed strong inhibitory effects on germination and seedling growth of P. alkekengi L. Therefore, it is possible to use methanolic extract at concentrations of 5 and 10 g/lit for controlling P. alkekengi L. Although benzene extract at high concentrations showed no strong inhibitory effect on germination, it was extremely effective in reduction of seedling growth that could be considered in management program of P. alkekengi L. control.
R. Bagheri; M.J. Arjomand Tajadini
Abstract
Some plants have negative effects on growth of the adjacent plants through excretion chemical compounds known as allelopathy. In order to cultivate Thymus caramanicus and Amygdalus scoparia (Agroforestry), this research was performed under laboratory conditions to determine the allelopathic effects of ...
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Some plants have negative effects on growth of the adjacent plants through excretion chemical compounds known as allelopathy. In order to cultivate Thymus caramanicus and Amygdalus scoparia (Agroforestry), this research was performed under laboratory conditions to determine the allelopathic effects of aerial extracts of Thymus caramanicus on some vegetative traits of Amygdalus scoparia in a completely randomized design with 3 replications. The results showed that different water extract concentrations of aerial parts of Thymus caramanicus had no significant effects on fresh and dry weights of underground parts of Amygdalus scoparia. However, germination percentage and fresh aerial weight were negatively affected at 50 and 100 gr/lit respectively. For other vegetative traits (germination rate, radicle length and aerial dry weight), 25 gr/lit was identified as the start of allelopathic effect. Since a threshold of allelopathic effect of Thymus caramanicus on different traits of Amygdalus scoparia was identified in this research, investigation on the same under natural conditions and different phonological stages is recommended.
M.Sh. Daneshmandi; M. Azizi
Abstract
In this research, the inhibitory effect of Eucalyptus globulus Labill. on germination and rhizome growth of Cynodon dactylon (L.) Pers. weed in three separate experiments were studied. In first experiment, after growing the weed, effects of different concentration of essential oils (20ppm, 50ppm, 100ppm) ...
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In this research, the inhibitory effect of Eucalyptus globulus Labill. on germination and rhizome growth of Cynodon dactylon (L.) Pers. weed in three separate experiments were studied. In first experiment, after growing the weed, effects of different concentration of essential oils (20ppm, 50ppm, 100ppm) as spray treatment on growth of the weed were investigated. In second experiment, effect of different level of Eucalyptus leaf litter (2, 5 and 10 w/w) as mulch treatments on germination of weed rhizome growth in a pot experiment were studied. In third experiment, effect of different concentrations of essential oils (20ppm, 50ppm, 100ppm) and leaf extract (25%, 50% and 75% water alcoholic extract) on in vitro rhizome germination were studied. Results indicated that leaf mulch had strong inhibitory effects on rhizome germination, that rhizome germination completely stopped in 50% w/w of mulch treatments. The highest number of germinated node (10.75 node/rhizome) was obtained in control treatment and the lowest one (1.5 node/rhizome) was detected in 10% mulch treatment. Essential oils spraying also showed inhibitory effect. After four months of spraying, all weeds became dried and died. Extract treatments also reduced growth of the weed as in lower concentration of extract (25%), germination of the rhizome was almost 66%, but in higher concentration (50% and 75%) complete inhibition of germination process take place. It was concluded that Eucalyptus globulus has a good potential to control Cynodon dactylon weed and it can be used as a herbicide in organic culture of the agricultural crops.
