Weed patch maps

Figure 4.5 An example of a weed patch map generated by detailed manual survey...

Weed populations tend to be veiy patchy over the field. It is very time-consuming to map weeds manually. Currently, automated systems for weed mapping are being developed. One option for some of the major weeds such as wild oats (because weeds spread by only a few metres per year) is to assess the weeds in early suimner before harvest and to produce a map. This map can then be used for patch spraying in future years. 

Ear characteristics are distinctive for most of the grasses as detailed below. Normally control is carried out before ear production. Ear number is important when assessing effectiveness of control that year weed mapping for patch spraying and checking for development of resistant plants. 

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