16 July 2022, New Delhi: Plant growth is affected in case of nutrient deficiency. The plant may not show symptoms of deficiency but its growth is severely affected. In case of severe deficiency, the plant shows symptoms of deficiency. These symptoms can be identified on leaves, specially plants with large leaves.
The symptoms can be identified based on (1) region of occurrence, (2) Presence or absence of dead spots, and (3) chlorosis of entire leaf or intervienal chlorosis.
The below Photo will help you identify major deficiencies in a plant :-
(1) Deficiency Symptom on Old Leaves
Old leaves can be identified as leaves which are fully developed and usually closer to the ground. The deficiency symptom appear in these leaves due to decreased mobility of nutrients in them.
(a) Dead spot on Old leaves (K, Mo deficiency)
A dead spot can be identified as brown lesion or dark coloured lesson of the lower leaf of the plants.
Potassium Deficiency (K), yellowing starts from tips or margins of leaves extending to leaf base. These yellow part become necrotic (dead spots) very quickly and appear usually on margins and tips.
Molybdenum deficiency (Mo) causes translucent spots of irregular shape in between veins of leaves. The spots are light green, yellow and brown in color. The spots are impregnated with resinous gum which exudes from rear side of leaf.
(b) No Dead spot on old leaves (N, P, Mg deficiency)
If there are no dead spot, look for other symptoms which can be identified on the leaf surface.
Check for Yellowing of old Leaves (N deficiency)
Yellowing of leaf including veins is a clear symptom of nitrogen deficiency. The leaves become stiff and erect specially in cereal crops. The leaf may detach with little forceful pull in extreme deficiency. Cereal crops show V-shaped yellowing at the tips of lower leaves.
Dark green, greenish red leaf (P deficiency)
Leaves are small, erect, unusually dark green with greenish red, greenish brown or purple tinge. The rear side develops bronzy appearance.
Yellowing in between veins (Mg deficiency)
Causes yellowing in between veins but veins remain green. The leaf is not erect. The leaf may also shed easily by wind. Necrosis or death of tissue occurs in extreme cases only in the margins.
(2) Deficiency Symptom on New Leaf
When veins remain green
Iron deficiency (Fe):
Veins remain green in iron deficiency. Other portions of leaf turn yellow and yellow to whitish. Under severe deficiency, the leaf becomes white.
Manganese Deficiency (Mn):
The principal veins as well as the smaller veins are green. The inter veinal portion is yellowish. Dead spots appear at large at a later stage. There is a chequered appearance to the leaf.
When veins not remaining green (Become Yellowish)
Sulphur deficiency (S):
The leaf become yellowish and looks like nitrogen deficient leaf. The leaf is small and the veins are paler than inter veinal portions. No dead spot appear.
Copper Deficiency (Cu): Leaf is yellowish and turn whitish at the end. In extreme deficiency, chlorosis of veins occur and leaf loses lustre. Leaf is unable to retain its turgidity and wilting occurs. Leaf detaches due to water soaked conditions of use of petiole.
(3) Deficiency Symptom New and Old leaf
Zinc Deficiency (Zn): The leaf becomes narrow and small. Upper surface of the leaf becomes chlorotic (Yellowish) but veins remain green. Subsequently dead spots develop all over the leaf including veins, tips and margins of leaf. In cereal crops, zinc deficiency generally appears in 2-4 leaves from top during vegetative stage.
(4) Deficiency Symptom Terminal Bud
Calcium deficiency (C): The bud leaf becomes chlorotic white while base remains green. The leaf tip hooks downwards and becomes brittle.
Boron deficiency (B): Causes yellowing of leaf which starts from the base to tip. The tip becomes elongated and becomes brownish or blackish. Death of terminal bud occurs in extreme cases.