The use of Roundup through Weed wipers

The weed wiping technique is widely used in arable crops and grassland to control volunteer crops like weed beet and general weed populations like Bracken, Rushes, Thistles and Ragwort in grassland.

Weed wipers may be used in any growing crop, providing the chemical does not touch the crop and in non-cropped areas to release desired vegetation or control injurious weeds covered by the Weeds Act 1959 or invasive alien weeds. They may be used in land which cannot be sprayed overall under SPS Cross Compliance or environmental stewardship restrictions, where target weeds include Broad-leaved Dock, Curled Dock, Creeping Thistle, Spear Thistle, Bracken, Common Nettle, Japanese Knotweed, Himalayan Balsam, Giant Hogweed and Ragwort.

Roundup products can be applied through all types of weed wipers, but must be diluted with the appropriate amount of water.


Use wipers when weeds are at or near their stage of growth for optimum translocation. Perennial broad-leaved weeds should be at or near flowering and perennial grass weeds should have at least 10 - 15cm (4"-6") of new leaf growth.

Treatment of Weeds

All weeds susceptible to glyphosate can be controlled by this technique provided they are sufficiently taller than the crop and are at a susceptible stage.

The target areas of weeds are the green leaves and green stems. Mature seed coats or fruits will not translocate the herbicide into the growing parts of weeds.

Weeds should be a minimum of 10cm, (4") taller than the desired vegetation for safe application. Weeds not touched by the herbicide will not be controlled: This may occur in dense clumps of weeds or where weeds are below the level of desired vegetation. Two passes in opposite directions will be needed where weeds are dense and successive applications will be required to control weeds that were below the original wiping level, when they reach the correct height for safe treatments.


This technique is particularly useful where reseeding is difficult due to soil type or in environmentally sensitive areas. It is also ideal where restricted pasture or high stocking levels do not allow for the stock exclusion period required by selective broad-leaved herbicides.

Provided seeds have not matured, treated seeds will be killed and will ensure minimum seed return. It is ideal to have a period of concentrated grazing just prior to wiping for maximum access to the target weeds.

Stock exclusion: Because of the high safety and environmental profile of Roundup herbicides, grassland with no poisonous weeds may be wiped and grazing animals returned as soon as the leaves are dry. This allows maximum utilisation of pasture and eases pasture management. Poisonous weeds which are not normally grazed by stock can become palatable as they die back after treatment.

Caution: Treated poisonous weeds, (including Ragwort, Hemlock, Water Dropwort and Bracken) must be removed or allowed to completely degenerate before re-grazing or conserving. Safe and efficient spot weeding can be achieved by allowing a minimum of 5 days undisturbed after wiping to allow the herbicide to be translocated to the roots before cutting and removal of poisonous weeds. This way grazing can be resumed and the weeds will not re-grow.

Weed wiper Machines and dilution rates

Wick types like the Hectaspan Weedwiper and the hand-held Microwipe use a herbicide-soaked rope wick to apply the herbicide. The concentration used is generally 1 part Roundup Biactive to 1 part water for tractor-mounted wick wipers. See table below for other products.

Under hot conditions a reduction of wicking ability may occur. Changing the concentration to 2 parts water to 1 part Roundup Biactive may restore wicking ability but a second application in an opposite direction to the first should be made to ensure adequate weed control at this concentration. The 2 parts water to 1 part Roundup dilution should always be used for the hand-held applicators such as the Microwipe. Ropes should be washed and cleaned several times a day to ensure optimum performance especially where dust and plant debris accumulate.

“New generation” wipers have largely superseded the wick types as they are much more efficient, less likely to block and give a better coverage. Rotary applicators can be either a continuous herbicide-soaked carpet like the Carier Rollmaster and the Rotowiper or a brush-type like the Logic Contact 2000. The C-Dax Eliminator uses wool wiping arms fed under variable pressure using a patented feed system and the WeedSwiper uses the patented Hydrostat fluid control to continually replenish fluid retentive pads and ensure no dripping. It is particularly important when treating weeds in horticultural crops to choose a machine which does not drip. Dilution is 1 part Roundup Biactive to 10 - 20 parts water.

Herbicide amount used will vary according to the density of weeds wiped, but as a rough guide about one third of the overall recommended rate for spraying will be used per hectare.


Do not treat when weeds are very wet or when rain is imminent. Direct run-off within the specified rain-free period could result in dripping of dilute Roundup onto the crop/plants below, resulting in crop damage.

Roundup BrandRoundup Biactive
Roundup Metro
Roundup ProBiactive
Roundup Energy Roundup Klik Roundup Ace
Roundup ProBiactive 450
Roundup MaxRoundup Ultimate
Hand-held wick-type wiper 1 part Roundup to 2 parts water 1 part Roundup to 3 parts water 180 g/l water 1 part Roundup to 3.5 parts water
Tractor mounted wick-type wiper 1 part Roundup to 1 part water or 1:2 in dry conditions 1 part Roundup to 1.5 parts water or 1:3 in dry conditions 280 g/l water or 180 g/l in dry conditions 1 part Roundup to 2 parts water or 1:3.5 in dry conditions
Rotary, carpet or brush wipers, pressure activated pad wipers Use 1-10 to 1-20 solution or as directed by manufacturers instructions Use 1-12 to 1-25 solution or as directed by manufacturers instructions Use 1kg in 20 litres or 1kg in 40 litres or as directed by manufacturer instructions Use 1-14 to 1-30 solutions or as directed by manufacturers instructions