Potassium carbonate and potassium bicarbonate and their use in plant cultivation

Potassium carbonate vs. potassium bicarbonate: differences

For a layman, there is virtually no difference between potassium carbonate and potassium bicarbonate. You should know, however, that these are different categories of salt. What are the characteristics of potassium carbonate? The label of this product indicates that it is:

• a crystalline, strongly alkaline (pH of approx. 11–12), hygroscopic substance that is well soluble in water (the alternative name of the compound is ‘potassium salt of carbonic acid’),
• an agent used for spraying plants before the flowering stage begins, among other things.

The term ‘potassium bicarbonate’ actually means potassium hydrogencarbonate – a white solid in the form of odourless crystals that are soluble in water. The pH of potassium bicarbonate is less alkaline than that of potassium carbonate (the difference is about 2 points on the pH scale).

Potassium bicarbonate sprays: what are they used for?

Both potassium bicarbonate and potassium carbonate in horticulture have replaced many chemical formulas for years. Both substances are used, among other things, for environmentally-friendly spraying aimed at eliminating fungal diseases of fruit shrubs and trees such as apple, pear, grapevine or certain species of decorative plants. Potassium bicarbonate prevents such diseases as:

• scab,
• powdery mildew,
• downy mildew,
• gray mould.

Potassium bicarbonate and potassium carbonate: orchard applications

In horticulture, organic and simple potassium bicarbonate  works well as an agent that stabilises soil pH levels and strengthens plant tissue. It enables plant cells to prolong their natural resistance to pathogens.

Potassium carbonate for powdery mildew

Powdery mildew and downy mildew are common fungal plant diseases. Both types of fungi form a characteristic white or greyish powdery coat on the surface of leaves. The fungi weaken the infected plants and significantly reduce the yield. How to reduce this fungal risk? An effective solution for mildew can be a potassium carbonate spray. Also mixed with cuprates, potassium bicarbonate yields positive results and effectively protects plants against infections.

Potassium carbonate for apple scab

Another very common fruit tree disease is apple scab. It is manifested by brown or dark green spots that cover the leaves and fruits. Scab significantly reduces the yield and makes the fruit tree gradually dry out. You can protect trees from this harmful fungus among others by performing potassium carbonate spraying on apple trees as a preventive measure, ideally in line with the horticultural calendar.

Potassium carbonate with urea is also used to control apple tree scab. Some fruit growers who raise organic crops also use potassium carbonate with cuprate. Both urea and cuprate eliminate scab spores, inhibiting the infection before it destroys the crop.

Read also about organic and ecological fertilisers.

Potassium bicarbonate vs. potassium carbonate: dosage

How does potassium carbonate work, how to use it for organic sprays and what are the right proportions of water and potassium carbonate or potassium bicarbonate? Every time you spray, you should check the dosing instructions in  the manufacturer’s recommendations and on websites managed by horticulture professionals. The amount of powder is usually given in units such as kg/ha and includes one-time doses as well as maximum doses.

Where else should you look for valuable insights on organic sprays and potassium carbonate? Online orchard forums and industry portals also provide a valuable source of information on the latest methods of controlling tree and shrub diseases. Fruit growers also get their knowledge of dosing salts from professional consultations with crop protection specialists. If you are looking for a reliable manufacturer of agrochemicals, you should definitely take a closer look at what PCC Group has to offer. In its broad range of products you will find lime fertiliser and chemical plant protection products.