Tomatoes need potassium more than any other nutrient. Without it, the tomato plant can’t produce the volume or quality of fruit that consumers demand. Sulfate of potash (SOP) provides tomatoes with the potassium they need, plus the added benefit of readily available sulfate sulfur with practically no chloride.

The Role of Potassium

Potassium (K) is essential to the tomato plant. It is absorbed more than any other nutrient and a deficiency in K can severely impact yield and quality of the fruit. The benefits of K for tomato plants include:

Aids in the transport of sugars

Helps with stomata function

Enhances skin set, color and taste

Aids the plant’s ability to resist disease

Sulfate Sulfur and Tomatoes

Because Sulfate of potash fertilizer offers 17% sulfur in the sulfate form, it is immediately available for uptake by a tomato plant. This is in contrast to elemental sulfur which needs significant time, correct temperature and moisture to convert to a plant-available form. Sulfur is essential for:

Promoting the production of enzymes, vitamins and proteins

Aiding photosynthesis and chlorophyll production

Enhancing root growth

Boosting the plant’s ability to resist temperature stress

Chloride and Salt Sensitivity

Chloride and salinity can pose serious problems to tomatoes. Chloride will compete with other nutrients at the uptake areas in the plant’s root zone, and this can lead to a potassium deficiency. Fortunately, Sulfate of potash contains less than 1% chloride, compared to other potassium sources like muriate of potash (MOP) which contains 47% chloride. Additionally, sulfate of potash has one of the lowest salt indexes of any of the major potash fertilizers, which helps manage the impact of a fertility program on soil salinity.