IN the fourth of our series of articles on spraying we look at hydraulic nozzles.
Agrochemical manufacturers nearly always give a preferred BCPC Spray Quality on the product label. A wrong spray quality or a poor pattern will almost certainly give a poor result.
To avoid that nozzle sets should be replaced after a targeted amount of work. Their output should also be checked regularly.
An uneven spray pattern is hard to see. So, during the season, be sure to check nozzle flow rates across the boom by collecting water in a measuring jug for a minute or half minute according to flow rate. Tips that are adrift by more than plus or minus 5% should be discarded.
At the end of a days work wash and clean nozzles. It is time well spent, often avoiding trouble when starting up later.
Dont reduce dose or application rates solely because you are using a novel type of nozzle – check trial results first. *
• Check labels for recommended BCPC spray quality required.
• Check which nozzles will give the right spray qualities at your speed of travel.
• Know the pressure range within which spray quality and pattern is maintained.
• Ensure nozzle angle gives adequate cover at the booms working height above target.
• Check nozzles to ensure they match and are of similar age.
• Carefully clean nozzles and filters at beginning and during season.
• DO NOT use hard objects or mouth to clean nozzle tips.
• Regularly check flow rate of each nozzle at working pressure – no more than 5% variation tip to tip.
• Run a 100m test in realistic field conditions to check sprayer output.
• Use colour coded tips or caps to avoid confusion.