Showing 5 results for Weed
Hosein Rezvani, Dr Jafar Asghari, Seyed Mohammadreza Ehteshami, Behnam Kamkar,
Volume 3, Issue 8 (11-2014)
Abstract
In order to evaluate light extinction coefficient and light use efficiency of wheat cultivars in densities of wild mustard, an experiment was conducted in Agricultural Research Station Gorgan during 2010-2012. The experiment design consisted of four randomized complete blocks in a factorial arrangement. The design consisted of two factors, four wheat cultivars and 5 levels of wild mustard densities. The results of means comparison of cultivar×wild mustard density interaction effect showed by increasing wild mustard density, light extinction coefficient increased in wheat different cultivars. In this research, the means of light extinction coefficient in the maximum of wild mustard density in Morvarid, Moghan, Arta and Tajan was 0.23, 0.51, 0.63 and 0.65, respectively. The highest and lowest of light extinction coefficient observed in Tajan and Morvarid, respectively. By comparing the vertical distribution of leaf area in wheat cultivars was distinguished that the highest of gathering amount of leaf area in all of investigated layers observed in Morvarid in competition and pure conditions. The highest of light use efficiency in the maximum of wild mustard density (32 plant/m2) observed in Morvarid (1.85 g/Mj) in the both of years, meanwhile, Tajan (1.21 g/Mj) had the lowest of light use efficiency. Totally, the results of this experiment in two years showed Morvarid had the highest of seed yield for the reason that the most of vertical distribution of leaf area and light use efficiency and too, the lowest of light extinction coefficient in compared to other cultivars, and was the more of succeed in competition with wild mustard.
, , ,
Volume 6, Issue 21 (11-2017)
Abstract
In order to study the allelopathic potential of six medicinal plants Valeriana officinalis, Rosmarinus officinalis, Artemisia absinthium, Melissa officinalis, Juglans regia, Dracocephalum kotschyi on Beta vulgaris and its two important weeds (Convolvolus arvensis and Avena fatua) and also to find a model of natural herbicides, a factorial experiment was conducted based on randomized complete block design. Shoots of B. vulgaris, C. arvensis and A. fatua were sprayed with water extracts (0 and 100 percent) of the allelopathic plants twice in 48h. Two days after spraying, the changes of dry weights, total water content, electrolyte leakage, concentrations of malondialdehyde (MDA), hydrogen peroxide, chlorophyll a, b, total chlorophyll and carotenoids were assessed in the target plants. Results of mean comparisons showed the water extracts of all studies medicinal plants had allelopathic effects on the target plants, but in different degrees. Amongst, D. kotschyi caused to make the least level of MDA (+%11.6), H2O2 (+%42), electrolyte leakage (+%8.5) and the least reduction of total chlorophyll (-%13.1) in B. vulgaris. These values were –in turn- (+%32.3, +2.6 folds, +%50 and -%48.4) in C. arvensis and (+%34.8, +3 folds, +%70.8 and -%56) in A. fatua. Generally, it is concluded that utilization of allelopathic ability of D. kotschyi would be a promising model to produce natural herbicide for sugar beet farms.
Noshin Ashna , Ali Ganjeali, Monireh Cheniany, Seyed Mousa Mousavi-Kouhi,
Volume 11, Issue 52 (3-2023)
Abstract
Allelopathic effect of apricot (Prunus armeniaca L.) root on some crops and weeds was investigated in two independent experiments. First, the effect of concentrations aqueous extract of apricot root (AAR) was assayed on the seed germination of Cicer arietinum L., Phaseolus vulgaris L., Triticum aestivum L., Zea mays L., Amaranthus retroflexus L., Secale cereal L., and Avena ludoviciana Durieu. In the second experiment, two pot trials were carried out to investigate the effect of AAR and apricot root powder (ARP) on the seedlings of P. vulgaris, Z. mays, S. cereal, and A. retroflexus. The results showed that germination was halted in T. aestivum, C. arietinum, A. ludoviciana, and S. cereal under all treatment levels, in A. retroflexus under 75 and 100%, and in P. vulgaris under 100% of AAR. Also, the results showed that effects of AAR and ARP on the biomass, membrane stability index, chlorophylls, carotenoids, proline, and protein content, and antioxidant enzymes activity were not significant, with a few exceptions. It can be concluded that the allelopathic effect of apricot root is mostly exerted by inhibiting the germination of target plants rather than effect on later stage of plant growth and development.
Reza Yaghmai, Vajihe Ganjeali, Mehrdad Lahouti, Monireh Cheniany,
Volume 12, Issue 56 (11-2023)
Abstract
The present study was performed to evaluate and compare the allelopathic effects of leaf aqueous extract and mulch of Eucalyptus (Eucalyptus globulus Labill.) on cucumber (Cucumis sativus var. beith alpha) and black nightshade (Solanum nigrum L.) seedlings in a completely randomized design. 21 days after treatment of seedlings with leaf aqueous extract (concentrations 5, 10, 15, 20 g L-1) and mulch (3% and 5% weight/volume), some morphological traits, membrane stability, proline and malondialdehyde content, total protein content and activity of polyphenol oxidase, and guaiacol peroxidase were analyzed. According to the results, although both aqueous extracts and mulch reduced the height and dry weight of aerial parts and the dry weight of roots in cucumber and black nightshade (compared to the control), the length of cucumber roots increased under the treatment of all the concentrations of aqueous extracts and mulch 3%. Evaluation of membrane stability index, proline and malondialdehyde content showed that the negative effect of mulch (3% and 5%) on black nightshade is significant. The treatment with aqueous extracts increased the activities of polyphenol oxidase and guaiacol peroxidase enzymes in cucumber (compared to the control), with the maximum ones in 20 g L-1 extract, while treatment with these extracts on black nightshade reduced the soluble protein content and enzymes studied. Overall, according to the results of this study, it can be stated that aqueous extracts showed a better ability to control black nightshade compared to leaf mulch, and it may be possible to use this type of treatment for herbicides in vegetable fields.
Alhasanayn Jasim Hasan Alnsrawi, Marjan Diyanat, Marzieh Ghanbarijahromi,
Volume 13, Issue 62 (10-2024)
Abstract
Weeds are one of the main obstacles to production in agricultural systems. The type of nutrient source and fertilizer can affect the density and flora of weeds, in addition to affecting the growth of agricultural plants. In order to investigate the effect of fertilizer sources on the zinia flower, a split-plot experiment was conducted in the form of a randomized complete block design with three replications on a private farm in Razavi Khorasan province (Khalilabad) in 2023. The investigated factors include two levels of weed presence and absence as the main factor in two levels (presence and absence (hand weeding)) and fertilizer treatment as a secondary factor in four levels (control (no use of fertilizer), fertilizer NPK chemical (according to soil test), vermicompost (5 tons per hectare), and animal manure (cattle manure) (10 tons per hectare). The results showed that all investigated traits of the Ahar flower showed a significant decrease in the presence of weeds. In the presence of weeds, the number of flowers in the cattle manure treatment was the highest (11.71). The consumption of all three sources of fertilizer caused a significant increase in density and dry weight of weeds, but the highest density and dry weight were observed (23.30 plants/m2 and 10.99 g/m2, respectively) in the treatment with chemical fertilizer. The chemical fertilizer treatment had the lowest competition index (0.79), which can be attributed to the higher weed biomass in this treatment. The highest competition index (1.37) belonged to cattle manure, which had a significant difference from other treatments. Therefore, it is recommended to use cattle manure in the field of weed infestation.
