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Pigeon pea (Cajanus cajan (L.) Millsp.)

Kumar, P.; Sharma, M.K. CAB International PDF

PIGEON PEA (Cajanus cajan

(L.) Millsp.)

NITROGEN (N) DEFICIENCY

Symptoms

Plate 208. Entire plant appearing light green.

(Photo by Dr Prakash Kumar.)

1. Nitrogen deficiency in pigeon pea is usually found during the initial stages of crop growth when root symbiotic nitrogen fixation nodules are yet to develop. The deficiency may also occur during later stages of crop growth when the symbiotic nitrogen-supplying mechanism is disturbed for some reason such as nodule infestation, nodule pathogenic disease or physiological causes.

2. The deficiency symptoms appear first and more severely on the old leaves. The younger leaves usually remain green and apparently healthy (Plate 207).

3. In mild deficiency, the entire plant appears uniformly light green

(Plate 208).

4. If deficiency persists and become more severe, the older leaves show chlorosis. Interveinal chlorosis appears on the oldest leaves in the beginning of the deficiency symptom (Plate 209), which soon converts to a uniform pale green, greenish yellow or pale yellow colour. The midrib remains green and turns yellow at last. Interveinal chlorosis stage is mostly missing in severe deficiency conditions.

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Lucerne or Alfalfa (Medicago sativa Linn.)

Kumar, P.; Sharma, M.K. CAB International PDF

LUCERNE or ALFALFA

(Medicago sativa Linn.)

NITROGEN (N) DEFICIENCY

Symptoms

1. Deficient plants become stunted and have sparse growth.

2. The stem becomes thin and elongated. The leaves become smaller and initially the entire plant appears chlorotic.

3. Since nitrogen is a mobile nutrient within plants, under short supply conditions it is quickly mobilized from lower to upper leaves. Thus the lower leaves display deficiency symptoms first.

4. The older leaves turn uniformly light yellow to dark yellow, while the younger leaves may remain light green (Plate 684).

5. The yellow older leaves then turn white and become necrotic.

Eventually, the leaves die and drop off early.

Plate 684. Light green upper leaves contrasted with yellow lower leaves. (Photo by Dr Prakash Kumar.)

Developmental stages

Stage I: In mild deficiency the entire plant becomes stunted and uniformly pale green (Plate 683).

Stage II: If the deficiency advances, the upper leaves appear pale green and the older leaves turn light yellow to dark yellow (Plate 684).

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Maize (Zea mays Linn.)

Kumar, P.; Sharma, M.K. CAB International PDF

MAIZE (Zea mays Linn.)

NITROGEN (N) DEFICIENCY

Symptoms

Plate 24. Young stage nitrogen-deficient crop.

(Photo by Dr Prakash Kumar.)

1. Maize is highly sensitive to nitrogen deficiency. Deficiency symptoms appear even in mild deficiency conditions. Nitrogendeficient plants are stunted with thin, spindly stems and pale green to yellow leaves. Deficient plants produce hardly one small ear per plant and the ears have hardly any grains with reduced kernel size, resulting in a drastic reduction in crop yield.

2. Nitrogen is mobile in plants and under short supply conditions it is easily mobilized from older to younger leaves. The deficiency symptoms appear first and become more severe on older leaves (Plate 23).

3. If deficiency occurs during the young stage of the crop, the whole plant appears uniformly pale green to yellow (Plate 24). In later stages of the crop, older leaves become pale yellow while young leaves remain green.

4. If deficiency persists or occurs in a more mature crop stage, a pale yellow chlorosis develops at the tip of old leaves and proceeds towards the leaf base along the midrib in a V-shaped pattern

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Cotton (Gossypium hirsutum Linn.)

Kumar, P.; Sharma, M.K. CAB International PDF

COTTON (Gossypium hirsutum Linn.)

NITROGEN (N) DEFICIENCY

Symptoms

Plate 584. Entire plant appearing light green and stunted. (Photo by Dr Prakash Kumar and Dr Manoj Kumar Sharma.)

1. Deficient plants appear stunted with short, thin stems.

2. A bright red pigmentation often develops on the lower parts of the stem.

3. The entire plant exhibits a light green appearance (Plate 584).

4. Younger leaves become smaller in size and the number of branches is reduced.

5. Nitrogen is a mobile nutrient in plants and it is rapidly moved from older to younger parts of the plants when its supply is reduced.

6. The deficiency symptoms appear primarily on older leaves and become more severe with time (Plates 583 and 585).

7. Initially, old leaves become pale green, then yellow and finally develop brown necrosis, usually in interveinal regions.

8. Eventually, the affected leaves die and fall off early.

Developmental stages

Stage I: In mild deficiencies, the entire plant appears uniformly light green in colour (Plate 584).

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Barley (Hordeum vulgare (L.) emend. Bowden)

Kumar, P.; Sharma, M.K. CAB International PDF

BARLEY (Hordeum vulgare (L.) emend. Bowden)

NITROGEN (N) DEFICIENCY

Symptoms

Plate 184. Close-up of chlorotic leaves. (Photo by

Dr Prakash Kumar and Dr Manoj Kumar Sharma.)

1. Being a fast-growing grass species, barley is very sensitive to nitrogen deficiency. Deficiency symptoms appear even in mild deficiency conditions.

2. Nitrogen-deficient plants are stunted with thin stems and pale green foliage. Affected plants lack vigour and produce small heads with few grains. In acute deficiency conditions, many young tillers fail to develop heads and die before maturity.

3. Nitrogen is mobile in plants and under short supply conditions it is easily mobilized from older to younger leaves. The deficiency symptoms appear first and become more severe on older leaves.

4. In mild deficiency conditions or during the young stage of the crop, the entire plant becomes pale green to yellow.

5. If deficiency persists and becomes more severe, a pale yellow chlorosis develops at the tip of older leaves and advances in a broad front towards the leaf base.

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