A Affect the whole plant or partial old leaves, especially old leaves in the lower part:
(1) Old leaves in the whole plant significantly become yellow and death if affect the whole plant: a. Light green leaves, short plants and thin and even broken stems, small leaves, light green leaves in the lower part, yellow leaves turning into brown leaves and death…… nitrogen deficiency b. Dark green leaves, slow growth, yellow and purple leaf veins (especially leaf stalk) in the lower part, early falling of leaves……phosphorus deficiency.
(2) Partially affect old leaves and leaves in the lower part: a. There are spots near the top and margin of leaves in the lower part, generally generating necrosis. The margin turns yellow and progresses to the middle part, and old leaves fall……potassium deficiency b. Leaves in the lower part is yellowing, and turn into necrosis in the later period. The part between leaf veins is yellowing, and leaf veins are green. The margin of leaves crumple up or down with sudden necrosis between leaf veins……magnesium deficiency.
B Affect partially new leaves:
(1) Apical buds grow well: a. Leaves are yellowing and leaf veins keep green: ① There are no bad spots generally. Under extreme situations, necrosis is observed in the margin and at the top and often developed inwards, and only large leaf veins keep green……iron deficiency ② Generally there are bad spots that scatter on the whole leaf surface in the square or net form, and only minimum leaf veins keep green. Flowers are small and the color is poor……manganese deficiency b. Leaves are light green, and leaf veins are lighter than the middle part in the color with less necrosis, and old leaves are fewer or do not die……sulfur deficiency.
(2) Apical buds die generally a. Necrosis is observed at the top and in the margin of leaves, and curves are found in the top. Before the above symptoms occur, roots have been dead……calcium deficiency b. The base of tender leaves is broken, and stem and leaf stalk are fragile. Meristems are dead and have the tendency of branch increasing……boron deficiency.
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