Iron Deficiency

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Iron Deficiency

Iron Deficiency

Deficiency


In a Nutshell

  • Leaves show chlorosis and turn yellow.
  • Leaf veins stay green.
  • Whole leaf may turn whitish yellow with brown spots and necrotic patches at margins.

Hosts

Additional

Apple

Apricot

Bean

Cabbage

Capsicum & Chili

Carrots

Chickpea, Gram

Citrus

Cotton

Cucumber

Currant

Eggplant

Garlic

Grape

Lettuce

Maize

Mango

Onion

Ornamental

Papaya

Pea

Peach

Pumpkin

Raspberry

Red gram, Pigeonpea

Soybean

Strawberry

Sugarcane

Wheat

Zucchini

Symptoms

Symptoms of iron deficiency first appear in the youngest leaves. It is characterized by the chlorosis (yellowing) of upper leaves, with the midrib and leaf veins remaining clearly green (interveinal chlorosis). At later stages, if no measures are taken, the whole leaf turns whitish-yellow and brown necrotic spots start to appear on the leaf blade, often leading to the development of necrotic patches on the margins. Affected areas can easily be identified from a distance in the field. Leaf chlorosis and necrosis reduce chlorophyll content, inhibit the photosynthetic rate, retard growth and lower the yield potential of the plant.

Trigger

Iron deficiency can be a serious problem in leached tropical soils or in poorly drained soils, mostly under cool, damp springs. Sorghum, corn, potatoes and beans are the most severely affected crops whereas wheat and alfalfa are the least sensitive. The absorption of iron by the plant and the yield response seem to be directly related to the percentage of CaCO3 in the soil and its pH. Calcareous, alkaline soils (pH 7.5 or higher) derived from limestone make plants especially prone to iron deficiency. Iron is important for photosynthesis and for the development and maintenance of root nodules in legumes. Therefore, iron deficiency severely depresses nodule mass, nitrogen fixation and crop yield. The estimated critical level is around 2.5 mg/kg of plant dry tissue. The deficiency of iron also increases the uptake and accumulation of cadmium in plants.

Biological Control

Small holders may use a leaf fertilizer made of nettle slag and algae extract. Application of animal manures, peat and composts also add iron to the soil. Plant dandelions in proximity of your crops, since it makes iron available to nearby crops, especially trees.

Chemical Control

Fertilize with iron-rich fertilizers. Iron is an integral part of most complete fertilizers. The application of nitric oxide (NO) alleviates leaf interveinal chlorosis and improves plant growth in plants suffering from iron deficiency in calcareous soils. This compound can also make iron more available to the plant. An example of treatment in case of acute deficiency could be: Spraying ferrous sulphate (5 g/l) + citric acid (1g/l), diluted in water, two times with weekly interval.

Preventive Measures

Chose varieties that are less susceptible to iron deficiency.,Fertilizers that contain iron as trace element are recommended.,Plant dandelion nearby cultivated plants.,If possible, avoid planting susceptible crops in calcareous, alkaline soils.,Improve the drainage of the soils and do not over-water.,Do not lime since this will increase soil pH levels.