Boom sprayers, aerial spraying, misters, blanket wipers, rope wick applicators, weed hunters, and back-pack sprayers are all examples of herbicide application methods. This section discusses the various herbicide application methods, including nozzles and equipment calibration.
Herbicide application methods
The most frequent type of herbicide application device in large-scale farming is a boom sprayer. The nozzles, which break the herbicide into many little droplets and project them through the air to the target, are the most significant component of a sprayer. The nozzle is the sole part of the sprayer that has a direct impact on spraying efficiency. All of the additional components are required to position the nozzles and give a constant flow of herbicide at the proper pressure. Spraying success hinges on proper nozzle selection and operation.
Misters are a convenient but inaccurate way to swiftly apply herbicides to vast regions. The herbicide is carried by the wind. The swath width will narrow if the wind is too light or the spraying speed is too high, potentially resulting in overdose and chemical waste. When the wind is too high or gusty, the swath width expands, reducing the chemical application rate and increasing the danger of spray drift damage.
Blanket wipers are made up of a horizontal frame and a vertical strip of material. The vertical strip, often known as a blanket, serves as a wiping surface for the target weed. This equipment was created as a replacement for rope wick applicators. The height differential between the crop and the weed is usually employed with a non-selective herbicide for successful weed control. Wipers are used to manage radish or mustard in lupins or chickpeas, as well as to ‘top’ grasses in pastures, in broadacre applications.
Hand-held equipment has been developed to manage weeds such as cape tulip, Paterson’s curse, Guildford grass, arum lily, fressia, and bracken fern in the back yard and in the environment. Herbicide can be administered selectively to these plants in revegetation regions without harming pasture legumes or native seedlings. When weeds are blossoming and 20–30cm taller than crop or pasture plants, September to early October is the optimal period to wipe them out in crops.
Rope wick applicators
Rope wick applicators are made up of a sequence of ropes impregnated with glyphosate, a non-selective herbicide. They’re not frequently utilised, although they’re effective at controlling tall weeds in crops and pastures. In this case, normal herbicide spraying with a non-selective herbicide would be impossible; however, a rope wick applicator can be moved above the crop or pasture and wipe the herbicide exclusively onto the taller weeds, resulting in selective control. For controlling cape tulip, docks, rushes, thistles, and bracken in pasture, this method has been moderately successful. Rope wick applicators have not gained widespread appeal because they can only operate at slow speeds and the ropes are quite expensive.
Detection technology (such as Weedseeker and Weedit) detects green weeds using infrared and near infrared light and sprays only green plants in paddocks. In action, light-emitting diodes (LEDs) point two separate light sources towards the ground: infrared and near infrared. Green weeds reflect light differently than stubble or soil. The device may travel at speeds of up to 20 kilometres per hour (km/h), which necessitates a steady boom for maximum effectiveness.