With warm weather starting to dry fields, growers are advised to ensure sprayers are ready to take advantage of forthcoming opportunities to get on the land.
While many sprayers have been stuck in the yard for months, black-grass plants have continued to grow freely in the fields – with a real risk that, diverting vital nutrients and light from cereal crops, they’ll soon start to affect yield potential.
So preparing your sprayer now could be the difference between excellent and poor control of black-grass this spring, says Professor Paul Miller from NIAB TAG.
“If we start preparing machines now, it means more time on the field once they’ve dried and a spray window presents itself.
“First things first: start with a clean machine. When conducting any tests or calibration of the sprayer with water ensure this water can be safely disposed of. If there is any risk that there is any pesticide in the water, it should not be put down the drain. And remember, any residue remaining in the tank could antagonize whatever active substance you’re using next.
“Then, make sure your machine has been NSTS tested. Twelve months is the recommended service interval to achieve a full compliance test.”
Professor Miller advises that if a machine has been tested, but was out of action for a few months, a good start would be a static boom test.
“Often overlooked, this involves fully extending the booms and setting them to half a metre above the ground. Then make a visual inspection to identify any mechanical damage or faults. Test the boom suspension by pushing down on either end of the boom and releasing it. The boom should bounce only once before returning to its original position. Any overshoot indicates a problem.
“If your boom wobbles, check to see if the dampers need replacing. If the boom is slow to return to the start position, lubrication may be required. Check that pipes running from the machine to the booms are correctly positioned and in good order.
“Cleaning all nozzles and filters is crucial. You want to prevent any build up of chemical behind the nozzles. This will reduce the risk of nozzle blockage resulting in striping and applying uneven chemical loads to the weed canopy,” concludes Prof Miller.
“There’s no point making considered decisions on which herbicide to use for black-grass control if you don’t take time to look after the sprayer,” says Ben Giles, Commercial Technical Manager at Bayer CropScience.
“Black-grass is now at various stages of tillering, depending on when the crop was drilled and whether a pre-emergence was applied in the autumn.
“While there is clearly a need to get on as soon as conditions allow, when black-grass plants are as small as possible, the method of application will have a significant bearing on product effectiveness.
“Good application technique will help deliver good levels of control. A forward speed of no more than12km/h, using 100L/ha of water and flat-fan nozzles producing a fine to medium spray quality is the most efficient way of covering the most hectares per day, which is vital if you’re to make the most from your window.”
“When the chance comes, by all means act swiftly. But make sure you apply to a reasonably dry leaf, and follow the application advice,” concludes Ben.