prediction of weed emergence timing would help minimize crop yield loss and reducing herbicide use by optimization of the timing of weed control. therefore, seedling emergence evaluation was conducted in different irrigation levels (40, 60, 80, 100 percent of crop water requirement and furrow irrigation) to develop a thermal time seedling emergence model for amaranthus retroflexus l. in sunflow...

a field experiment was conducted to study the spatial relationships between weed seed bank and population and their distribution models in sugar beet crop (beta vulgaris) in 2009 at motahari  agricultural research station of karaj. sampling from seed bank before sugar beet drilling and weed population in three stages during the growing season were done using square (50*50 cm) and rectangle (25*...

to evaluate the competition effect of velvetleaf on cotton, an experiment was conducted in a completelyrandomized block design with split plot arrangement of treatments with three replications at experimentalstation of gorgan university of agricultural sciences and natural resources during 2011 growingseason. the treatments were three row spacing (20, 40 and 80cm) of cotton (as main plot) and f...

A season-long survey of common weeds was taken near onion and potato fields located within a large vegetable production region in western New York in 2008 and 2009. The objective was to determine the abundance of weed species known as hosts for Iris yellow spot virus (IYSV), a serious pathogen of onion, Potato leafroll virus (PLRV) and Potato virus Y (PVY), which are major pathogens of potato. ...

this experiment was carried out at the research farm of faculty of agriculture, university of zanjan in spring of 2012 to introduce an integrated weed management method in fennel. treatments were type of herbicide (trifluralin and pendimethalin), application dose (recommend dose in other crop (r), 75 percent r, 50 percent r, and 0 percent r) and supplemental control (none, one hand-weeding at 5...

In a single experiment, field-grown Louisiana sugarcane was augmented with phytoparasitic nematodes, treated with aldicarb, or left untreated in both weedy and weed-free habitats to study interactions among nematodes, weeds, sugarcane, and sugarcane free amino acid titers. Aldicarb reduced three of the six phytoparasitic nematode genera at various times during the two growing seasons and was as...

Organic farming has been identified as promoting soil quality even though tillage is used for weed suppression. Adopting zero tillage and other conservation tillage practices can enhance soil quality in cropping systems where synthetic agri-chemicals are relied on for crop nutrition and weed control. Attempts have been made to eliminate tillage completely when growing several field crops organi...

Conventional soybean weed management and transgenic herbicide-tolerant management were examined to assess their effects on soybean insect pest populations in south Georgia in 1997 and 1998. Soybean variety had very little impact on the insect species observed, except that maturity group effects were observed for stink bug, primarily Nezara viridula (L.), population densities on some sampling da...

Six species of insects and a rust fungus have been successfully established for biocontrol of the weed Parthenium hysterophorus L. in Queensland, Australia. Effectiveness of biocontrol insects was evaluated at two properties in Queensland during 1996-97 based on an exclusion experiment using insecticides. Parthenium-infested plots with and without biocontrol insects were sampled at monthly inte...