Therefore, at least one or more postemergence applications will be required. Proper identification of emerged weeds can affect the success of postemergence herbicide applications, since not all herbicides control the same weeds. Weed size at time of herbicide application can also affect herbicide performance. Larger weeds may require a higher rate for effective control. Always consult the label to determine the rate needed to control a particular weed or weed size.
Environmental conditions can affect postemergence herbicide performance.
It is best not to apply herbicides when the crop or weeds are under stress, since this can lead to lower weed control and increase crop injury. Tank mixing certain herbicides postemergence can also result in antagonistic response, eg. To overcome antagonism, increase the rate of the grass herbicide in tank-mixtures. Consult the label of the specified grass herbicide to be applied postemergence for tank-mixtures with herbicides for broadleaf weed control. Cultivation Cultivation is often used to supplement other methods of weed control.