abstract in order to evaluate the effect of different nitrogen application methods on yield and yield components of winter wheat, a field experiment with split plot arrangement in completely randomized blocks design with four replicates was conducted in 2006. basal dressing in three levels (1- with no basal dressing, 2- strip and 3- distributing nitrogen fertilizer) as main plot and top dressin...

Glyphosate is the most widely used herbicide in the world for several reasons, including: 1) high level of effectiveness, 2) flexibility in application, 3) large margin of crop safety in glyphosate resistant crops, and 4) safety to applicators and the environment. Glyphosate was used for more than 20 years before weeds developed resistance to the chemical. This relative low risk of glyphosate r...

by the publication of a high-quality genome sequence—only the third such sequence for any plant species (Tuskan et al. 2006). In spite of over 200 field trials of GE trees that have been reported in at least 35 countries, the only commercially deployed transgenic trees are insect-resistant Populus nigra and white poplar (clone 741) in China (Food and Agriculture Organization 2004), and virus-re...

Cogongrass, an invasive grass native to Asia, has infested thousands of hectares in the southeastern United States. Although numerous studies have examined cogongrass control, no published studies, to our knowledge, have tested strategies for cogongrass eradication. Cogongrass has a persistent, thick rhizome mat but an ephemeral seedbank; therefore, successful eradication methods must largely f...

Herbicide resistant weed populations have developed due to the repeated application of herbicides. Elevated concentrations of atmospheric CO2 can have positive effects on weed growth, but how rising CO2 might affect herbicide resistant weeds is not known. Ragweed (Ambrosia artemisiifolia L.) ecotypes known to be resistant or susceptible to glyphosate herbicide were exposed to either ambient or ...

this experiment was conducted for three consecutive years from 2000 to 2002 to evaluate the effects of integrated weed management on weeds of alfalfa at the safi abad agricultural research farm of dezful. the experimental design was a randomized complete block with strip-split plot arrangement of treatments. herbicide treatment was as horizontal factor at five levels which in 2000, consisted of...

Application of 4-amino-3,5,6-trichloropicolinic acid (picloram) to roots stimulated the production of ethylene in both mesquite [Prosopis juliflora (Swartz) DC. var. glandulosa (Torr.) Cockerell] and huisache [Acacia farnesiana (L.) Willd.] seedlings. Herbicide levels rose in tissues before we detected increased ethylene production. Rates of ethylene production by various parts of the plant par...

Tradescantia 4430 clone stamen hair mutation (Trad-SHM) bioassay was used to evaluate the genotoxicity of a herbicide composed of triazines (atrazine and simazine) after in situ exposure. Thirty plant pots were exposed during the herbicide application (test group) and a control group was maintained in a greenhouse (control group). Genotoxicity was expressed in terms of pink mutation events (EMP...

After cultural treatments such as site preparation, release and fertilization, changes in the supply of mineral nutrients relative to each other and shifts in the composition of vegetation may have a delayed effect on the nutrition, carbon partitioning and growth of forest trees. This study was conducted to evaluate the influence of early management options that control vegetation and fertility...