Improved methods for fogging crops in store identified

17 September 1999

Improved methods for fogging crops in store identified

NEW ways to optimise distribution of CIPC sprout suppressant in stored potatoes have been pinpointed at Sutton Bridge Experimental Unit.

Nearly half the 3.5-4m tonnes of UK stored potatoes are fogged each year with the chemical.

"CIPC is by far the most effective sprout suppressant we have, but we must recognise that it is being applied directly to potatoes for consumption," said BPC member and director general of the Potato Processors Association, Richard Harris.

As yet the chemical has no maximum residue level. But for the industrys image as well as pure economic reasons it made sense to ensure it was used responsibly.

"One of the most important things in our industry is to make sure consumers are completely satisfied in the safety, quality and wholesomeness of our produce. There have been so many food scares. The last thing we want is a potato scare."

The key was to minimise chemical inputs consistent with good agricultural practice, he said.

The latest work, in conjunction with Silsoe Research Institute and Glasgow University, dispelled fears that variable fog particle size might cause problems. Provided applicators are correctly set up, all the main products on the market produce the optimum particle size of 2-8µm, said Adrian Cunnington of Sutton Bridge.

Work in box stores highlighted the importance of avoiding temperature gradients by recirculating the air inside stores before introducing CIPC. That avoided differential condensation, especially in the top of stores with "overhead throw" refrigeration, said Mr Cunnington.

Five-minute bursts of ventilation immediately after treatment and again every hour for four hours thereafter have also been found to achieve more even distribution.

Although some growers attempted the job, fogging with CIPC was best left to professionals, warned Mr Harris. To protect themselves growers should make sure firms offering their services are members of the National Association of Agricultural Contractors, are BASIS-trained, hold PA1 and PA9 certificates and have adequate insurance cover. "Insist that they have ISO 9000 and also carry the appropriate safety equipment such as breathing apparatus and mobile phone," he advised.

lSBEU, which came back under the BPC wing in March, remains a unique research and storage facility, says BPCs Mike Storey. But it has to compete in exactly the same way as other proposers when it comes to research projects, he stressed.


&#8226 On nearly 50% stored crop.

&#8226 Responsible use vital.

&#8226 Remove temp gradients.

&#8226 Pulsed ventilation useful.

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