Nutritional Deficiencies/Disorders of Fennel

Nitrogen

Pale or yellow green leaves (chlorosis) symptoms appear fi rst in the older leaves. Reddish tints gradually appear at the leaf margins spread toward the midrib or central vein. Leaves are small. Overall growth is markedly reduced.

Correction measure: Foliar spray of urea 1% or DAP 2% twice at weekly intervals.

Phosphorus

Slow plant growth, leaf colour may intensify, browning or purpling in foliage in some plants, thin stems, reduced lateral breaks, loss of lower leaves.

Correction measure: Soil application of recommended dose of phosphorous should be applied at the time of sowing or planting.

Potassium

Since potassium is very mobile within the plant, symptoms only develop on young leaves in the case of extreme deficiency. Reduced growth, shortened internodes, marginal burn or scorch (brown leaf edges), necrotic (dead) spots in the leaf, reduction of lateral breaks and tendency to wilt readily.

Sulphur

Stunted plant growth, leaves turn to pale yellow. The leaves show a general overall chlorosis. Under severe deficiency, the yellowing is much more uniform over the entire plant including young leaves.

Correction measure: Foliar spray of K₂SO₄ or CaSO₄ @ 1% twice at fortnightly interval.

Magnesium

Symptoms appear on the older leaves. Older leaves may fall off, or they develop a triangular arrowhead at the base of the leaf, near the stalk. Reduction in growth, marginal chlorosis, interveinal chlorosis (yellow between the veins) in some species, eventually the whole leaf becomes yellow.

Correction measures: Foliar spray of magnesium sulphate @ 0.5 % ( 5g MgSO₄ dissolved in 1 lit of water) in the interval of 15 days on the foliage till the symptoms disappear.

Manganese

Symptoms occur on new growth. Leaves appear mottled, light green to yellow green in-between the veins.

Correction measure: Foliar spray of MnSO₄ @ 0.5% twice at weekly interval.

Iron

The deficiency of iron shows up first in the young leaves of plants, which develop interveinal chlorosis and it progresses rapidly over the entire leaf. In severe cases, the leaves turn completely white.

Correction measure: Soil application of FeSO₄ at 12 Kg/acre followed by foliar spray of FeSO₄ @ 0.5% during 3rd, 4th and 5th months.

IPM for Fennel

To know the IPM practices for Fennel, click here.

Source: NIPHM and Directorate of Plant Protection, Quarantine & Storage