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Knapsack spraying onions


This video offers hints for better onion spraying and follows on from our video on spraying pesticides downwards. Click the play button to view the video now or click on the script tab to view the storyboard. To view the video off-line, click the link from the 'download' tab.


To grow a well-established crop like this one, early weed control is essential. At the early growth stages vulnerable seedlings easily lose the competition for light, water and nutrients. At later growth stages pests and diseases can cause problems.





The leaves of the onion plant are often widely spaced, waxy, thin and upright, which means that the spray drops are not easily retained when spraying insecticides and fungicides.





Your pesticide label therefore, may also advise the use of wetters, surfactants or ‘stickers’ to improve the retention of spray drops; so that the drops are more likely to remain on the leaves.





Where your pesticide label advises using small drops, project the drops at an angle to the vertical, upright leaf. Bear in mind that the problem with smaller drops however, is that they are more likely to drift in wind or evaporate in high temperatures and so you must pay particular attention to the weather conditions at the time of spraying. Have a look at our 5 day weather and spray conditions forecast for more information.




The key to achieving an even coverage of all the foliage is to follow the advice on your pesticide label for water volumes, drop sizes and spraying pressures for your crop, growing under your conditions.





Also take particular care to position your nozzle or boom at the right distance from the crop and maintain that distance throughout the spraying process.

Have a look at our video 'calibrating your knapsack sprayer' for advice on getting the balance of nozzle type and size, knapsack sprayer pressure, spraying distance and spraying speed just right.

For more information about using pesticides and which PPE to use, visit