scholarly journals Allelopathic Effect of Powdered Russian Knapweed (Acroptilon repens L.) on the Growth Parameters of Redroot Amaranth (Amaranthus retroflexus L.)

2013 ◽  
Vol 5 (3) ◽  
pp. 360-363
Author(s):  
Alireza PIRZAD ◽  
Mousa JAMALI ◽  
Mohammad Amin ZAREH ◽  
Fahime SHOKRANI

To evaluate probable allelopathic effect of different parts of Russian knapweed (Acroptilon repens L.) on the growth of redroot amaranth (Amaranthus retroflexus L.) seedling, a factorial experiment was conducted based on randomized complete block design with three replications at the Faculty of Agriculture, Urmia University in 2012 (Iran). In this experiment, treatments were different parts of Russian knapweed (aerial part, flower and root) in different amounts (1, 2, 3 and 4 g/pot). Pots included 300 g of soil. Results showed the significant effect of Russian knapweed plant parts on the seedling emergence percent, root length, ratio of root/shoot length, seedling length, seedling fresh weight, and the significant effect of plant material amounts on the seedling emergence percent, seedling fresh weight and seedling dry weight. Interaction effect between plant material type and amount on the shoot length, root length, ratio of root/shoot length, seedling length was significant, too. The longest shoot (3.51 cm), root (1.75 cm), the highest ratio of root/shoot length (0.49) and seedling length (5.26 cm) belonged to control treatment. The highest seedling emergence percent of Amaranthus retroflexus (34.73%) and seedling fresh weight (0.176 g) were occurred at pots treated by Russian knapweed aerial part. The lowest seedling emergence percent (21.94 %) and seedling fresh weight (0.111 g) were obtained from application of Acroptilon repens powdered root. The maximum seedling dry (0.0126 g) and fresh (0.177 g) weight of Amaranthus retroflexus were obtained from control treatment.

2012 ◽  
Vol 4 (2) ◽  
pp. 108-111
Author(s):  
Alireza PIRZAD ◽  
Mousa JAMALI ◽  
Mohammad Amin ZAREH ◽  
Fahime SHOKRANI

To evaluate probable allelopathic effect of water extract originated from different parts of russian knapweed (Acroptilon repens L.) on growth of purslane (Portulaca oleracea L.), a factorial experiment was conducted based on randomized complete block design with three replications at greenhouse condition in 2011. Treatments were water extract concentrations (0, 5, 10, 15 and 20 percent) obtained from different part of russian knapweed (aerial part, flower and root). Results showed the significant effect of extract type on seedling length, and extract concentration on shoot length, root length and seedling length. Interaction effect between extract type and concentration on the ratio of root/shoot length, seedling fresh weight, seedling dry weight and germination percentage was significant, too. Means comparison indicated that the longest root (3.55 cm), shoot (4.65 cm) and seedling (8.20 cm) were obtained from control treatment, reducing with higher concentration of extract. The longest shoot (6.95 cm) belonged to extract originated from russian knapweed flowers. The highest ratio of root/shoot length (0.73), seedling fresh weight (0.61g) and seedling dry weight (0.044 g) belonged to control treatment. In general, increasing of extract concentration caused in reduction of germination and seedling traits. Meanwhile, extracts of aerial part had more sever reducing effect than root and flower extracts.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 501D-501
Author(s):  
M.H. Aboul-Nasr ◽  
S.Z. Elagamy ◽  
A.M. Kassim

Three strawberry cultivars were used in this study. Runners from the three cultivars were grown on Murashige and Skoog medium supplemented with benzylaminpurine or kinetin at four concentrations (2, 1, 0.5, and 0.25 mg·L-1 in addition to the control treatment). The use of cytokinin, regardless of type and concentration, promoted the explant proliferation, shoot height, number of leaves, and plantlet fresh weight. Callus formation was enhanced by BA application, especially with `Pajaro'. However, `Chandler' did not form at all using cytokinin. Produced plantlets had lower nutrient constituents (N, P, K, Ca, and Na) when grown on media containing cytokinin compared to the control. Based on these results, cytokinin is recommended to get more shoots per explant. Furthermore, using the lowest concentration (0.25 mg·L-1) will produce height proliferation, greater shoot length, and more leaves.


HortScience ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 100-103
Author(s):  
Ahmet Korkmaz ◽  
Wallace G. Pill ◽  
Bruce B. Cobb

The effect of seed germination rate, or of seedling emergence rate, was studied in relation to subsequent plant growth of `Cortina' lettuce (Lactuca sativa L.). Seedling growth response to selection by time of germination was assessed by imbibing seeds at 5 °C to increase the time range for germination. Germinated seeds were removed daily and transferred to “slants” (germination paper held at 20° from vertical) at 15 °C. Five days after each transfer, root and hypocotyl lengths were measured. As days required for germination increased, root lengths decreased and hypocotyl lengths increased, resulting in no change in total seedling length. The relation between rate of seedling emergence from raw or pelleted seeds of the same lot and shoot fresh weight was examined using commercially practiced hydroponic techniques. Shoot fresh weight at 10 and 21 days after planting was related inversely and linearly to the day of emergence for both seed treatments. In the same study, the coefficient of variation of shoot fresh weight was positively related to time of seedling emergence only at 10 days. Germinated seeds were selected after 1 and 2 days of imbibition; subsequent seedling emergence rate and shoot fresh weight at 25 days were recorded. First-day germinated seeds had faster and more synchronous emergence, and produced heavier and more uniform shoots. Discarding slow-to-germinate seeds should enhance seedling emergence and growth.


2020 ◽  
Vol 9 (1) ◽  
pp. 814-818

Effect of Carthamusoxyacantha powder aqueous extract on seed germination of Wheat and Maize were studied. Powder extract of 3g, 6g and 9g of concentration were soaked in distilled water for 12 Hrs, 24 Hrs and 36 Hrs of time. The seeds of Wheat and Maize were germinated in Petri dishes. Control was maintained by watering the seeds with distilled water. The highest values for germination percentage, shoot length, root length, fresh weight, dry weight, seedling length, vigor index and seedling weight vigor index were recorded in control of wheat the above parameter decreased with increasing concentration and timing. While in maize highest values for the above parameters were recorded in treatments as compared to control.


Weed Science ◽  
1993 ◽  
Vol 41 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Ismail B. Sahid ◽  
John B. Sugau

Laboratory, greenhouse, and field studies were conducted to determine the allelopathic potential of lantana and Siam weed on the germination and growth of five crops. Emergence and dry weight of bioassay species were affected when lantana or Siam weed debris was present on the soil surface or incorporated into the soil. However, presence of Siam weed on the soil surface did not affect dry weight of rape. Emergence and dry weight of crops (except emergence of spinach) were not affected when crops were grown in soil samples collected from beneath field-grown lantana. Dry weight of Chinese cabbage and chilli was reduced when these crops were grown in Siam weed-contaminated soil. Germination of Chinese cabbage, chilli, and rape decreased progressively when exposed to increasing concentrations of aqueous lantana extract. However, the lantana extract at full strength (66.7 g L−1) did not reduce germination of spinach and cucumber seed. Siam weed extract, when applied at full strength to seed of spinach, Chinese cabbage, rape, and chilli, reduced germination by 10, 12, 21, and 19% of control, respectively. Full-strength extract of lantana and Siam weed decreased seedling length and fresh weight of all crops.


HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 912D-912
Author(s):  
Ahmet Korkmaz ◽  
Wallace Pill

Achievement of head size uniformity at final harvest reduces loss and increases profitability for the hydroponic lettuce grower. Shoot fresh weight of `Cortina' lettuce (Lactuca sativa L.) at 7 or 21 days after planting (DAP) was inversely proportional to the number of days required for seedling emergence, and was greater for raw than for pelleted seeds. Head fresh weight at final harvest (61 DAP) was directly proportional to seedling length at 21 DAP, but raw and pelleted seeds produced equal head weights. Thus, initial seed (seedling) vigor differences were maintained to final harvest. Osmotic seed priming (–1.5 MPa KH2PO4, 20 h, dark) led to increased germination rate at 15, 25, and 35C; had no effect on germination synchrony; and increased germination percentage only at 35C. Covering raw or pelleted seeds sown in depressions of the phenolic foam trays with fine (No. 5) vermiculite compared to leaving the seeds uncovered, and soaking the trays in hydroponic solution rather than water, increased seedling shoot fresh weights. Seeds sown on their first day of germination or primed seeds gave greater seedling shoot fresh weights than pelleted seeds. However, the more uniform seedling shoot fresh weights from germinated seeds than from primed seeds was associated with more rapid and synchronous seedling emergence.


2017 ◽  
Vol 12 (1) ◽  
pp. 89
Author(s):  
Silvana Fraga Silva ◽  
Halina Stéffany Lopes Costa ◽  
Jesimiel Silva Viana ◽  
Sebastião Medeiros Filho

Biological invasions of exotic plants can seriously contribute to ecological imbalances within areas to which they have been introduced, affecting, in addition to native plants, cultivated species. Consequently, the objective of the current study was to evaluate effects of allelopathic extracts of three exotic species on the physiological quality of crambe seeds. Aqueous extracts of Prosopis juliflora (Sw.) DC (algaroba) were formulated; Azadirachta indica A. Juss (Nim) and Cryptostegia madagascariensis Bojer ex Decne (viuvinha) at 20% (200 g of dried leaves per liter of distilled water) placed in B.O.D at 25 ° C for 24 h. Petri dishes, lined with germitest paper sheets, were moistened with aqueous extracts at 2,5 times de paper weight. In the experimental trial, we used the completely randomized, with four treatments (three extracts + control treatment) and four replicates of 25 seeds. The first and second germination counts were evaluated in the fourth and tenth days respectively; germination rate index (GRI), allelopathic effect index (AEI), seedling length and dry mass. P. juliflora and C. madagascariensis reduced germination by 84 and 91%, respectively, in the first count. The GRI was affected by the three species, while the AEI showed greater allelopathy for C. madagascariensis, reaching -0.90. Seedlings lengths were reduced in the presence of P. juliflora and C. madagascariensis. For crambe seeds, all extracts negatively affected their physiological potential.


2019 ◽  
Vol 37 ◽  
Author(s):  
B. GUL ◽  
S. IJAZ ◽  
H. KHAN

ABSTRACT: An experiment was conducted to investigate the allelopathic effects of lotus (Nelumbo nucifera Gaertn.) and arrowhead (Sagittaria sagittifolia (Brummitt & Powell): L.) on seed germination of wheat and two associated weeds, namely, wild oat (Avena fatua L.) and milk thistle (Silybum marianum (L.) Gaertn.). The experiment was laid out in a Completely Randomized Design during May, 2014. Dried biomasses of lotus and arrowhead leaves were soaked in distilled water for 48 hrs for extract preparation. The extracts were applied at a rate of 5 and 10% concentrations to the seeds of wheat, wild oat and milk thistle at 25 °C in 10 cm wide Petri plates. A control treatment where only distilled water was applied to the seeds, was included for comparison. Data were recorded on germination (%), shoot length (cm), shoot and root fresh weights (g). The results revealed that 10% lotus extract reduced germination of wild oat (0.00%) and milk thistle (13.3%) but comparatively enhanced that of wheat (20%). By contrast, arrowhead totally inhibited germination of wheat and wild oat as compared to milk thistle (16.66%). Similarly, 10% lotus extract favored shoot length and root weight of wheat and milk thistle, whereas 100% inhibited wild oat. By comparison, arrowhead completely inhibited shoot length and root weight of wheat and wild oat at 10% conc. and enhanced milkthistle (3.00 cm and 3 g). A higher lotus extract conc. affected wild oat more than wheat and milkthistle, while arrowhead weed affected almost all test species. In conclusion, these aquatic weeds can be used as mulch in wheat in nearby fields of the infested aquatic water bodies for wild oat control, weed biomass disposal and nutrient addition to the soil.


2020 ◽  
Vol 12 (4) ◽  
pp. 163
Author(s):  
Ariadne Waureck ◽  
Ana Dionisia da Luz Coelho Novembre

For seeds organic production the control of fungi with chemical fungicides is not indicated, which requires the use of biological products. In this sense, the use of essential oils derived from plants is a possibility for microorganisms control. This study evaluated technical feasibility of applying the essential oils of clove, lemongrass, rosemary, eucalyptus, ginger and Tea tree, in concentrations of 500, 1.000, 1.500 and 2.000 μL-1 to organic coriander seeds of the Verdon variety, besides the control. At the beginning of storage and every 60 days the seeds were evaluated for water content, germination, germination velocity index and root emission, seedling emergence and seedling emergence speed index, to shoot length, rootlength, total length and sanity. The experimental design was a completely randomized (DCR), in a 6x4 + 1 factorial scheme, with six essential oils and four concentrations + control treatment, with four replications for germination and vigor analysis, and eight replications for sanitary analysis. With increasing concentration of essential oils, there was a linear reduction in germination and a reduction in the incidence of Alternaria sp. using clove and rosemary oils at a concentration of 500 μL L-1, eucalyptus at a concentration of 1.500 μL L-1 and ginger with 2.000 μL L-1. Therefore, it is possible to use clove and rosemary essential oils up to 500 μL L-1 to reduce the incidence of Alternaria sp. without causing significant reduction in germination.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 480e-480
Author(s):  
Nancy H. Furness ◽  
Mahesh K. Upadhyaya ◽  
Douglas P. Ormrod

Relative sensitivity of selected vegetable and weed seedlings to ultraviolet-B (UV-B) radiation (280–320 nm) was investigated. Seedlings were grown for 4 weeks in a greenhouse, in chambers equipped with UV-B-emitting fluorescent tubes and Mylar (control) and cellulose acetate (UV-B) filters. UV-B radiation reduced seedling height, leaf area, and leaf fresh weight in tomato (Lycopersicon esculentum `Cour Di Bue'), broccoli (Brassica oleracea var. Italica `Purple Sprouting'), cabbage (Brassica oleracea var. Capitata `Red Drumhead'), and cucumber (Cucumis sativus `Straight Eight'), leaf area and leaf fresh weight in beet (Beta vulgaris `Cylindra' and `Early Wonder'), seedling height and leaf area in spinach (Spinacia oleracea `Long Standing Bloomsdale'), lettuce (Lactuca sativa ``Red Salad Bowl Everest') and `Savoy' cabbage, and seedling height in `Chinese Tip Top' cabbage and lettuce (`Saladin'). `Winterton' cabbage was not affected. UV-B radiation decreased leaf area and leaf fresh weight in common chickweed (Stellaria media) and corn spurry (Spergula arvensis) and seedling height in green foxtail (Setaria viridis) and redroot pigweed (Amaranthus retroflexus). Tillering was stimulated in response to UV-B in green foxtail. There was no effect of UV-B on lady's-thumb (Polygonum persicaria) growth. Leaf number was not affected by exposure to UV-B in any species. The differential morphological sensitivity of vegetable and weed seedlings may result in altered competitive relationships under enhanced UV-B levels expected with the depletion of the earth's ozone layer.


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