Press Release · 20th May 2007

Controlling blight in conventional
and organic potatoes

Law’s, the independent company supplying fertilisers and crop protection to the market, is receiving considerable interest in their copper-based fungicide, Wetcol 3 which is suitable for both conventional and organic potatoes.

“Potato planting has been well ahead of previous years and growers understand the need to protect their investment right from the start as soon as the crop starts to emerge. Already Smith periods have been recorded in many parts of the UK and early spraying will have started. Although there is a wide range of fungicides available, there are very few that can be used on both conventional and organic crops. Fully approved, Wetcol 3 is a copper-based fungicide registered for use in potatoes as well as a wide range of vegetable and fruit crops. It is a blend of purely naturally occurring ingredients including copper as a tetracopper tricalcium sulphate and soluble calcium, formulated as a stable dispersion. In addition to blight prevention, the soluble calcium in Wetcol helps to reduce internal rust spot in potatoes and can help skin finish,” explains Mark Law, Managing Director of Law’s.

“Coverage of the potato foliage is essential for any protectant fungicide and Wetcol has a modern up to date formulation that will ensure good coverage. It contains its own naturally-based spreaders and stickers which add to its effective coverage, whilst maintaining its approval for use in organic farming. The product has a very fine particle size of just 2 microns, resulting in better leaf coverage and rainfastness, important in a showery weather or under irrigation regimes,” reminds Mark.

“This fungicide has shown effective control against potato blight, providing application and coverage is adequate. There is no reason why conventional growers as well as organic growers shouldn’t gain from its efficacy,” says Mr. Law.

“Both The Soil Association and Organic Farmers & Growers permit the use of Wetcol 3 where need can be justified which is easily proved with the recording of Smith periods. Furthermore, there are no effective resistant potato varieties and blight can severely reduce yield and quality within a few weeks of the initial infection. Growers have little option if they are to grow a good yielding and high quality crop,” says Mark.

“We would advise growers to get ahead of the game and apply for use of Wetcol straight away. Obviously for conventional growers Wetcol is fully approved and they can get on and protect their crop with no further complications,” says Mark.

Wetcol is recommended in potatoes for the control of late blight. It is applied at dose rates of 25-50 litres per hectare in 800 litres of water, to ensure complete coverage of the crop canopy. It is recommended as a first spray or as advised and repeated at 10-14 day intervals using the higher doses later in the season.


Wetcol contains copper. Wetcol is a registered trademark of
Law Fertilisers Ltd.

For further comment and information please contact Mark Law, Managing Director, Law Fertilisers Ltd on on 07710 324463 (mobile) or via e-mail

Editors Notes
Law Fertilisers manufacture a range of granular blends, using the highest quality raw materials and tailored to individual crops needs. Their integrated service is based on soil and plant sampling, sound scientific research and many years experience. Products are supplied directly onto farm, in bags or bulk and can be delivered and spread using in-house spreading service at a considerable cost saving.

Law Fertilisers aims to provide an independent, professional and targeted approach to fertiliser use in all major crops on the farm, including potatoes, cereals, oilseed rape, sugar beet and vegetables. They also have a unique range of fertilisers and inputs suitable for organic crops.


Law Fertilisers Ltd.
The Fertiliser Factory
Wimblington, March
Cambridgeshire PE15 0QJ
Tel : 01354 740740 Fax: 01354 740720