As featured in Arable Farming Magazine
Pellet quality key as spread width widens
by Arable Farming August 2020
Slug pellet spreadability is a science in itself. But getting the right combination of applicator, pellet and spread width is important to efficacy. Marianne Curtis reports.
Slug pellet spreadability is crucial to maximising effective uptake of the active ingredient and for growers operating over wider widths, choosing a pellet that is capable of travelling over longer distances is important.
Uniform coverage and spreading consistency is required to attract the slug to the pesticide.
Slug pellet manufacturer De Sangosse tested its slug pellet spreadability alongside that of three competitors (see panel) using a range of applicators – StocksAG Fan Jet Pro 65, Bullock Tillage De Limbe and StocksAG Fan Jet Duo – in conjunction with SCS Sprayer and Spreader Testing.
Both wet-processed pellets performed more consistently with respect to spread pattern differences between left and right, says Phil Carpenter of De Sangosse.
To counteract any side wind during slug pellet application, particularly on wide working widths, an overlap of about three metres is desirable, says Mr Carpenter.
Slug pellets used in the trial
- De Sangosse TDS wet-processed
- Frunol lentil wet-processed
- Dof dry-processed
- Neudorrfe wet-processed
- Note: Apart from De Sangosse, products the manufacturing process is given, not brand.
“The Neudorrfe wet process pellets spread to 24m with the StocksAG Fan Jet Pro 65 but, with no achievable overlap registered, it would be better to reduce working width or use the De Sangosse pellet which was able to spread a further 2m,” he says.
“This would safeguard against wind speed changes and achieve a more consistent application.”
The lentil-shaped pellet saw mixed results both in maximum working width and consistency left and right, says Mr Carpenter.
“It wasn’t able to spread quite as far as the De Sangosse TDS wet-processed or Neudorrfe wet-processed pellets in either the StocksAG Fan Jet Duo or StocksAG Fan Jet Pro 65.
“The Bullock Tillage applicator appeared to favour the physical characteristics of the lentil pellet, achieving more consistent left to right spread and better spreading distances.
“Also, one thing to note, if this pellet is propelled from the machine on its flat profile it flies like a discus. However, the ones turning in the air and catching
face on into the wind did not fare so well.
“This became more evident in the high speed camera tests where you could see each individual pellet leaving the disc from the spreader.
“This may also explain the variation on the left and right percentage difference results [12% for StocksAG Fan Jet Pro 65].”
The dry processed pellets’ spreading capability was improved to 30m by using the StocksAG Fan Jet Duo machine compared with the StocksAG Fan Jet Pro 65 (18m), matching the lentil-shaped pellet and just 2m behind the wet-processed alternatives.
The lowest variation at 12m and up to the achieved maximum distance was recorded by the De Sangosse pellet, says Mr Carpenter.
“The key message is to match your pellet profile to the applicator you are using and adjust expectations accordingly.”
SCS engineer comments the limiting
JSCS engineer Jim Hammond says the StocksAG Fan Jet Pro 65 spreads the De Sangosse pellet to 24 metres with other pellets struggling to get that far.
For certain machines the quality of pellet is not that significant as the machine is the limiting factor in terms of spread width, he says.
“If you are spreading 12m, the pellet is not that important unless you are worried about dust. As you get to a wider width, that is when the pellet becomes a lot more important.
“If it has a higher bulk density it will come off the disc faster and go further.
If it is less dense it will be more affected by the wind.”