management of nitrogen fertilization in crops is one of the most important components of integrated weed management. a two-year field experiment was conducted to determine the direct effects of wild mustard aboveground biomass and n content of wild mustard on oilseed rape yield. a set of factorial treatments was arranged in a randomized complete block design with four replications. treatments w...

In dryland farming areas of Montana, annual precipitation is not sufficient for annual planting of cereal grains. Instead, a crop-summer fallow farming system is used to conserve soil moisture and increase available nitrogen for subsequent crop growth. Managing this summer fallow, either by mechanical means or with herbicides, is the highest variable cost associated with dryland grain productio...

Weedy and invasive plants cost Americans billions of dollars annually in crop damage and lost earnings. Various Western states have reported annual weed control costs in the hundreds of millions of dollars. Herbicides account for more than 72 per cent of all pesticides used on agricultural crops. $4 billion was spent herbicides in the US in 2006 and 2007 (Grube, et al, 2011). The USDA Economic ...

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...

The ability to manage weed infestations in a spatially precise manner will rely on the availability of efficient methods of mapping weed distributions. We have conducted a study designed to compare four different ground based methods for collecting georeferenced information on sterile wild oat infestation in a winter barley crop. Sampling was done at harvest time (when wild oat panicles are mos...

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 ...