Potassium deficiency (K)
The symptoms of potassium deficiency in olive trees will first show on older leaves, but will later also affect younger leaves. Leaves will be smaller than usual, with brown spots on leaf tips or close to leaf tips, and may roll in if the situation is not remedied.
It is advisable to conduct a calculation of fertilizer requirements, which should be based on the results of a soil analysis, on the actual crop requirements and on the expected yield. A lack of potassium during the vegetation period may be remedied by foliar application of potassium sulfate in the form of a specialty fertiliser, such as HORTISUL®. In case of fertigation, preference should be given to using sulfatic fertilisers as potassium sources (HORTISUL®).