These should be controlled, regardless of their number, to prevent them from spreading. The lost income from downgrading must be considered in the decision to spray, as it may significantly lower the threshold that makes spraying worthwhile. It is impossible to predict weed densities in a field based on the number of weeds that set seed the previous year, but you can assume that there will be more weeds each year if control action has not been taken. If applied properly, herbicides can effectively control all but the most serious of weed densities. If you choose not to spray to control seed development, guard against increased weed densities by growing a competitive crop that allows effective herbicide options.
Many producers prefer to spray when in doubt, rather than calculating the economic threshold.
Below is an optional method for determining whether to spray. YES Determine the leaf staging of your crop and the wild oats. The wild oats are one leaf stage ahead of your crop. Spray only if you have 5 OR MORE wild oats per square metre. The wild oats are the same leaf stage as your crop.