Boron (B) deficiency symptoms

Boron (B) deficiency symptoms:

• Symptoms include marginal leaf curing and deformation, and most commonly white stripes appear perpendicular to the veins on the young emerging leaves.
• The new leaves may have an incomplete lamina similar to sulphur and calcium deficiency with thickening of secondary veins.
• Inhibition of root and flower formation is also observed in the affected plants.
• Boron and Calcium deficiency symptoms tend to overlap. See Calcium deficiency pictures also. 
• Once a plant shows of signs of deficiency, take immediate remedial steps suggested here below, since the plants will not fully recovery once the damage is already happened.

Control Measures:

a.  Apply 10g Borax/plant in 3^rd month or when deficiency occurs, once only. 
                                                (OR)

b.  Spray Boric acid @ 1g/litre of water 2-3 times, weekly.
                                                (OR)
c. Spray Solubor @ 1g/litre of water 2 times in a month. (Excess application will harm the plant).
                                                (OR) 
d. Apply Sodium tetraborate @ 25 gms per plant and irrigate immediately.

Picture 1: Boron deficiency symptom:

(The central new leaves have incomplete lamina).

Picture 2: Boron deficiency symptom:

(The central new leaves have incomplete lamina).

Picture 3 Boron deficiency symptom:

(The central new leaves have incomplete lamina).

Picture 3 Calcium + Boron deficiency symptom: Deformed and whitish heart leaf. 

Picture 4: Early foliar symptom of calcium + boron deficiency - Wrinkled leaf.

Picture 5: Early foliar symptom of calcium + boron deficiency- Spike leaf in which the lamina of new leaves is deformed or almost absent). 

 

 Picture 6: Boron deficiency symptom: Deformed leaves and improper filling and cracking of fruits.

Regards,

A.Vishnu Sankar

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Posted in: 34. Boron (B) deficiency symptoms

IRON (Ferrous-Fe) deficiency symptoms

IRON (Ferrous-Fe) deficiency symptoms:

• Leaves exhibit white/yellow chlorosis of the entire lamina and green band along the margin and mid-rib.
• The chlorosis is more acute in spring and autumn than in summer, and is more evident under dry conditions.
• Plants are generally stunted and the fruits are smaller in size.

Control Measures:

   a.   Manual application of ferrous sulphate @ 20g/ plant.

                                      (OR)

   b.   Spray chelated Ferrous salt @ 2g/l of water weekly once for 2-3 weeks.

Photo courtesy: TNAU, Tamilnadu, India.

Very severe stage of Ferrous deficiency

Ferrous deficiency in early stage

Iron (Fe) deficiency in calcareous soil

Iron deficiency is common and one of the most difficult deficiencies to correct in calcareous soils. A calcareous soil contains a high concentration of calcium carbonate and has a pH of about 8.3.

The symptom of Fe deficiency is known as “iron chlorosis” and is called “lime-induced chlorosis” when it occurs on calcareous soils. Deficiency symptoms occur on young leaves, which appear light yellowish to white in color, with the veins greener than the remainder of the leaf.

Ferrous deficiency symptoms in calcareous soils

Iron deficiency can be induced by high levels of P and Cu in the soil and commonly associated with Zn and Mn deficiencies.

Ferrous sulfate does not provide sufficient available iron when applied to either acid or alkaline soils because it quickly transforms to iron oxide.  Foliar application of Fe is not recommended due to lack of effectiveness and the most reliable means of correcting Fe chlorosis is by soil application of iron chelates.

Regards,

A.Vishnu Sankar

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Posted in: 33. IRON (Ferrous-Fe) deficiency symptoms