Consulta: creatorFacets:"Gherekhloo,J."
Registros recuperados: 6
Data/hora: 13/06/2024 07:17:52

Multispecies weed competition and their economic threshold on the wheat crop
Provedor de dados: Planta Daninha
Autores: Gherekhloo,J.; Noroozi,S.; Mazaheri,D.; Ghanbari,A.; Ghannadha,M.R.; Vidal,R.A.; Prado,R. de.
Two field experiments were conducted to evaluate the effects of multispecies weed competition on wheat grain yield and to determine their economic threshold on the crop. The experiments were conducted in 2002, on two sites in Iran: at the Agricultural Research Station on Ferdowsi University of Mashhad (E1) and on the fields of Shirvan's Agricultural College (E2). A 15 x 50 m area of a 15 ha wheat field in E1 and a 15 x 50 m area of a 28 ha wheat field in E2 were selected as experimental sites. These areas were managed like other parts of the fields, except for the use of herbicides. At the beginning of the shooting stage, 30 points were randomly selected by dropping a 50 x 50 cm square marker on each site. The weeds present in E1 were: Avena ludoviciana,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Weed interference; Competition; Grain yield; Mathematical regression.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582010000200002

Influence of environmental factors on seed germination and seedling emergence of yellow sweet clover (Melilotus officinalis)
Provedor de dados: Planta Daninha
Autores: Ghaderi-Far,F; Gherekhloo,J.; Alimagham,M.
Laboratory and greenhouse experiments were conducted to determine the effects of drought and salinity stress, temperature, pH and planting depth on yellow sweet clover (Melilotus officinalis) germination and emergence. Base, optimum and ceiling germination temperatures were estimated as 0, 18.47 and 34.60 ºC, respectively. Seed germination was sensitive to drought stress and completely inhibited at a potential of -1 MPa, but it was tolerant to salinity. Salinity stress up to 90 mM had no effect over the M. officinalis seed germination, but the germination decreased by increasing the salt concentration. The drought and salinity required for 50% inhibition of maximum germination were 207 mM and -0.49 MPa, respectively. High percentage of seed germination...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Germination; PH; Salinity stress; Soil depth; Temperature; Water stress.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582010000300002

Some biological aspects of the weed Lesser celandine (Ranunculus ficaria)
Provedor de dados: Planta Daninha
Autores: Sohrabi Kertabad,S.; Rashed Mohassel,M.H.; Nasiri Mahalati,M.; Gherekhloo,J.
Lesser celandine (Ranunculaceae) is a perennial weed with tuberous root. Tubers are the most important means of reproduction and dispersion of this weed. In recent years, it has spread into wheat fields in Western Iran, mainly in the Lorestan province. A series of experiments were conducted to determine cardinal temperatures and to study the effects of pre-chilling, temperature fluctuations, tuber size, freezing and drying on germination of the tubers, as well as the effect of planting depth on sprouting of the tubers. The results obtained showed that the highest percentage of germination occurred when tubers were stored for more than 2 weeks at 4 or 8 ºC. The optimum temperature for germination differed in large and small tubers (8 and 14oC,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Freezing; Germination; Osmotic potential; Tuberous root.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582013000300010

Effect of desiccation and salinity stress on seed germination and initial plant growth of Cucumis melo
Provedor de dados: Planta Daninha
Autores: Sohrabikertabad,S.; Ghanbari,A.; Mohassel, Mohamad,H.R.; Mahalati,M.N.; Gherekhloo,J.
Smellmelon, an annual invasive weed of soybean production fields in the north of Iran, reproduces and spreads predominately through seed production. This makes seed bank survival and successful germination essential steps in the invasive process. To evaluate the potential of Smellmelon to invade water-stressed environments, laboratory studies were conducted to investigate the effect of desiccation and salinity at different temperatures on seed germination and seedling growth of Cucumis melo. Seeds were incubated at 25, 30, 35 and 40 ºC in the darkness in a solution (0, -0.2, -0.4, -0.6, -0.8, 1 and 1.2 MPa) of a salt (NaCl), and in a solution (0, -2, -4, -6, -8, -10, -12 bar) of PEG-6000 (Polyethylene glycol), in two separate experiments. The results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Germination; Osmotic potential; Cucurbitaceae; Seedling vigor index (SVL).
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582013000400009

Factors affecting Cyperus difformis seed germination and seedling emergence
Provedor de dados: Planta Daninha
Autores: Derakhshan,A.; Gherekhloo,J.
Specific knowledge about the dormancy, germination, and emergence patterns of weed species aids the development of integrated management strategies. Laboratory studies were conducted to determine the effect of several environmental factors on seed germination and seedling emergence of Cyperus difformis. Germination of freshly harvested seeds was inhibited by darkness; however, when seeds were subsequently transferred to complete light they germinated readily. Our results showed that 2 wk of cold stratification overcome the light requirement for germination. Seeds of C. difformis were able to germinate over a broad range of temperatures (25/15, 30/20, 35/25, and 40/30 ºC day/night). The response of germination rate to temperature was described as a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Osmotic potential; Salinity stress; PH; Soil depth; Temperature.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582013000400008

Effect of plant density and seed position on mother plant on physiological characteristic of cocklebur (Xanthium strumarium) seeds
Provedor de dados: Planta Daninha
Autores: Foroughi,A.; Gherekhloo,J.; Ghaderi-Far,F.
Experiments were conducted in 2010 to determine the influence of plant density and seed position on the mother plant on seed physiological characteristics of cocklebur (Xanthium strumarium). Cocklebur burs were collected in fall of 2010 from Research Farm of University of Agricultural Sciences and Natural Resources of Gorgan, Iran. The experiment was established as factorial arrangement using a completely randomized design with three replications. The factors included different densities of cocklebur (0, 2, 4, 6 and 8 plant m-2) and the top and bottom parts of the canopy. Non dormant seeds were used for determining cardinal temperatures and tolerance to salinity and drought stresses. Base, optimum and ceiling germination temperatures were estimated between...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Shade environment; Cardinal temperature; Competition; Dormancy.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582014000100007