Following five simple practical measures will help ensure potato growers optimally apply sprout suppressant CIPC in store, and meet forthcoming maximum residue legislation.
“This year’s stored crop will be the first that has to meet the EU-wide 10ppm CIPC maximum residue limit,” says the British Potato Council’s Adrian Briddon.
It is a limit growers should be able to comply with.
“But there are some simple things growers can do to improve performance.”
First, growers must segregate crops, he says.
“It is probably too late for this season, but it’s very difficult to defend pesticide use on crops that don’t need it.”
Only crops that break dormancy will need an application of CIPC, he says, so don’t keep crops with differing dormancy levels together.
Where an application of CIPC is a certainty, make sure the initial treatment goes on early.
“If you leave it too long, you end up having to put more chemical on.
The first application should be made by the eyes open stage, at the latest.”
Once treated, get the temperature down as low as the quality specification makes possible, he advises.
“Good temperature control improves efficacy.
The lower the temperature, the longer the period of sprouting control.”
Distribution is improved by even temperatures.
Where stores have fridges, they should be switched off a few hours before application, sometimes for up to 24 hours, he says.
“If you have temperature differentials, use fans to even them out.”
Lastly, leaky stores must be attended to, although he recognises it is difficult to control leakage in large structures with lots of seams.
“Ambient louvres are a good example,” he says.
“They often don’t seal well, and as the store is pressurised at application, are a source of leakage.
Get them fixed before application.”