Weed wiper

The main problem with the development of weed wipers has been to control delivery of sufficient liquid to the pad, so that it is wet enough to transfer the... 

Figure 5.9 Selective application of a herbicide with a weed wiper. Photo G. A. Matthews...

A disadvantage of a weed wiper is that when a treatment is complete there can be a large area of the wiper still contaminated with herbicide. This has to be hosed off with water, using a brush to ensure penetration of the absorbent surface. It is important to ensure that the herbicide contaminated washings can be disposed of safely and, when dry, the wiper should be covered by a protective sleeve. 

These devices are used to apply contact or translocated (systemic) herbicides selectively to weeds in crop areas. Wicks made of rope, rollers made of carpet or other material, or absorbent pads made of sponges or fabric are kept wet with a concentrated mixture of contact herbicide and water and brought into direct contact with weeds. The herbicide is "wiped" onto the weeds but does not come in contact with the crop. Application may be to tall weeds growing above the crop or to lower weeds between rows, depending on the way the wiper elements are designed. Pumps, control devices, and nozzles are minimal or are eliminated altogether, and tanks are quite small because of the small amount of liquid applied. 

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