Definitions: Chlorotic/Chlorosis - Lack of green pigment, yellowing.
Necrotic/Necrosis - Dead or dying tissue.

A. PRIMARY ELEMENTS

1. N-
Deficiency symptoms first occur on the older leaves. Look for a pale green color which then turns yellow green and finally pale yellow as the deficiency becomes more severe. Plants will be stunted due to lack of nitrogen.

2. P-
Older leaves appear abnormally dark green or purplish.

3. k-
Pronounced necrosis - plants not particularly stunted, but leaves (particularly older ones) scorched at tips and outer margins. Leaf margins may be crinkled and curled.

B. SECONDARY ELEMENTS

1. Ca-
Young leaves in bud becomes hooked in appearance and die - back at the tips and along the margin. In somes cases the young leaves remain folded. Sometimes leaves have wrinkled appearence. Older leaves become thick and brittle.

2. Mg- Older leaves predominently mottled - interveinal chlorosis. Starts at the bottom of the leaf and moves upward.

3. S-
Like nitrogen, a general yellowing of the entire leaf, but appears on the new young leaves first.

4. Fe-
Begins as mild interveinal chlorosis on the young leaves. Becomes progressively more yellow to cream color and as deficiency becomes more severe, veins becomes bleached. New leaves will be smaller.

5. Mn-
Interveinal chlorosis on young leaves. Similar to iron deficiency, but not as severe. Veins remain green and leaves are not stunted.

6. Zn-
Chlorosis, crinkling, waving of young leaves.

7. Cu-
Severe stunting and terminal leaves become very small. Terminals die, causing multiple buds to form beneath it called "Witches Broom".

8. B-
Internodes become noticeably shorter. Stems become thick and brittle, and leaves become small and stiff. New growth is abnormally small, blunt, and thickened.