Farmers should check the integrity of crop protection products held in their stores following the recent spell of extremely cold weather, according to the AtlasFram Group.

The UK's largest farmer-owned farm inputs purchasing and crop marketing business has warned that the protracted cold spell in December and January may have adversely affected products held in on-farm stores.

John Humphreys, arable products manager for AtlasFram Group, said: "This has undoubtedly been the worst winter for almost 20 years, with temperatures down to between -5°C and -10°C in many areas, but falling to as low as almost -20°C in some parts of Scotland and the North West. Due to the value of crop protection products, most farmers will take care to ensure that they are stored under adequate conditions, but given the exceptionally severe weather it is certainly worth checking all products that have been on the farm during that period.

"Where products were held for a considerable period in stores that are poorly insulated or not entirely weatherproof the cold might have penetrated, potentially reducing their effectiveness. The type of formulation rather than the active ingredient will have the greatest potential impact.

"Solid materials which exist as grains or powders, will be unaffected by cold conditions, but some suspension concentrates may be a little more susceptible, as well as the occasional emulsifiable concentrate. In some cases one or more of the active ingredients may have fallen out of suspension, the most affected products typically being concentrated suspension formulations such as fungicides. This will inevitably affect the materials' physical characteristics, alter their application characteristics or reduce their agronomic effectiveness. Where separation of the active ingredients has occurred, we recommend that farmers speak to the relevant manufacturer to seek best advice.”

If for any reason product cannot be used then it must be disposed of appropriately in accordance with the statutory requirements of the Food and Environment Protection Act 1985 by law.