Sulphur deficiency (S)
Diffuse yellowing on youngest leaves, sometimes marbled. Leaves form spoon shapes, curl upwards and may become brittle. Later, flowers are reduced in number and are markedly pale.
Treatment: Foliar application of EPSO Top® or EPSO Microtop®. Korn-Kali® with 5% S and ESTA® Kieserit gran. with 20% S are excellent choices for preventive applications, as the contained sulphur is fully water-soluble and is therefore immediately available to plants.