abstract in order to determine the critical period of weed control in euro-flour variety of sunflower (helianthus annus, l.) an experimental was conducted with a randomized complete block design with 10 treatments and three replications in islamic azad university astara-branch-agricultural college in 2006 growing season. experimental treatments were conducted in two sets, the first set included...

in this study, the performance of different cultivation methods on sugar beet fields was evaluated. eight treatments were considered: a) use of a rolling cultivator twice during the growing season; b) use of a rolling cultivator three times during the growing season; c) use of a crescent cultivator twice during the growing season; d) use of a crescent cultivator three times during the growing s...

introduction the main goal of this study was to perform quality control test on all radiography units operating in golestan province of iran. materials and methods forty-four x-ray units were examined based on general accepted programs for quality control. eight parameters including kvp accuracy, kvp reproducibility, ma-time reciprocity, exposure linearity, exposure reproducibility, timer accur...

Good management models for postemergence weed control require good estimates of which weed density produces an economic threshold yield. Because intraweed competition increases if weeds are aggregated, weed spatial pattern may be an important factor for inclusion in management models. Mathematical models of weed–crop competition have demonstrated that this may be the case, but the small number ...

The critical period for weed control (CPWC) is the period in the crop growth cycle during which weeds must be controlled to prevent unacceptable yield losses. Field studies were conducted in 2005 and 2006 in the University of Birjand at the south east of Iran to determine CPWC of corn using a randomized complete block design with 14 treatments and four replications. The treatments consisted of ...

velvetleaf (abutilon theophrasti) is one of the most important weeds of soybean fields in golestan province. a field experiment was conducted in gorgan agricultural research station in 2007 to determine the critical period for velvetleaf control in williams soybean (glycine max (l.) merr.) cultivar using a randomized complete block design with 4 replications. treatments were included two sets o...

Returns of an individual enterprise in the short term are usually measured through a gross margin budget, which is determined by subtracting factors such as the cost of weed control (both herbicide and non-herbicide) and other inputs (eg seed and fertiliser) from gross income (calculated as crop yield multiplied by grain price). Crop yield is directly influenced by weed density, which itself is...

in this study, the effects of weed control treatments and plant density on lentil (lens culinaris) yield and yield components as well as weed control efficacy were investigated. the study was conducted according to a split-plot arrangement based on randomized completely block design in three replicates in karaj in 2007-2008. the weed control chemical treatments in four levels (trifluralin herbi...

abstract in order to study of chemical and mechanical weed management methods and their integration in potato (solanum tuberosum), a field experiment was done in 2008 at ferdowsi university of mashhad research field. experimental design was completely randomize block design with 6 treatments and 3 replications. treatment included broadcast herbicide application (standard treatment), between row...

Soybean field experiments were performed to investigate the weed-suppressing effects of different tillage systems and cover crop mulches at two locations in southwest Germany during 2014 and 2015. The influence of three different tillage systems on weed control efficacy, soybean plant density, and crop yield was determined. In the no-till system (NT), two different cover crops, (rye and barley)...