The following table summarises the effect of each element and provides a guide to identifying deficiencies.
| Nitrogen (N) |
Affects cell structure and promotes leaf growth. |
Stunted, pale green or yellowing of the leaves often with reddish tints. |
| Phosphorus (P) |
Promotes seedling development, root growth, and the formation of flowers, fruits and seeds. |
Poor root development and stunting of seedlings. Often a purple discolouration in the leaves. |
| Potassium (K) |
Promotes cell strength and water movement within the plant. Affects the growth and quality of flowers and fruit. It also assists the plant resist stress from pests, disease and climatic extremes. |
Weak stems and floppy leaves especially the older ones, with yellow/brown spots and fewer or smaller flowers. |
| Calcium (Ca) |
Cell wall construction. Promotes healthy growing tissue including root tips. |
Weak stems, dark brown or black leaf tip discolouration, particularly on older leaves. |
| Sulphur (S) |
Assists in the formation of many plant proteins and chlorophyll. |
Yellowing of leaves and stunting of roots. |
| Magnesium (Mg) |
Essential in photosynthesis. |
Yellowing of the leaf edges most noticeably on the older leaves. |
| Trace Elements |
Although essential they are only needed in very small quantities,to regulate plant growth and assist in the building of compounds within the plant. |
Varies depending on the severity of the deficiency and the particular plant. |
