Brassicas

These are the members of the family Brassicae and familiar names include cabbage, cauliflower, Brussels sprout, calabrese. Turnips and swede are also in the this group and have remarkably similar requirements despite quite a different appearance.

Brassica vegetables are known to have a great demand for nutrients and cauliflowers in particular require excellent soil fertility to produce a reasonable crop. They are also characterised by a high requirement for Sulphur which is used not only alongside Nitrogen for growth but also for the production of the aromatic compounds which give these vegetables their characteristic ‘love em or hate em’ taste which is generally popular in the UK. These vegetables, particularly at the early seedling stage are sensitive to soil chloride levels which can inhibit root growth if at high concentrations. Growers therefore generally apply the bulk of potash fertiliser (as muriate of potash or MOP) well before planting to allow rainfall to wash away the soluble chloride. With the use of patentkali however, due to virtually nil chloride levels (potash is in sulphate form), the fertiliser can safely be applied at any stage of the crop. Not only does this give greater flexibility to the grower but it also provides the entire Sulphur requirement for these crops.