Fertilizer burn - Effect of excessive use of chemical fertilizers,

What is fertilizer burn?

The chemical fertilizers that we use for farming are hygroscopic in nature. When a farmer applies excess chemical nutrients and fails to water the plants sufficiently, the applied chemicals because of their “thirsty” nature starts absorb water particles not only from the soil but also from the plant roots.

This withdrawal of water from the plant tissues (dehydration) will cause ‘drying out’ of tender parts like roots and foliage. This injury will be visible very soon after the application of fertilizers like browning of part or all of the foliage. In some cases, severe injury will cause death of the entire plant. Since the symptoms in the leaf look like 'thermal radiation burn out' this is called “Fertilizer burn’.

Remember: “Over fertilizing is just as bad as under fertilizing”.

Fertilizers are normally soluble but some are highly soluble. The higher the solubility of a chemical fertilizer then higher the chances of “burn” if not used properly.

In most of the ‘burn out’ cases, it was found to be the application of excess nitrogen beyond the needs of the plant that caused the plant burn.

A case history:

Fertilizer burn may occur to plants that are provided with drip / fertigation system also.

Continuous fertigation, less water and hot climatic condition may cause ‘burn’ as happened to a Banana farmer who had applied 200gm of Single Super Phosphate and 100gm of Di Ammonium Phosphate as basal fertizers and after a week started to give daily dose of 1gm each of Ammonium Sulphate, Urea, Calcium nitrate, Potash and water soluble 19:19:19 (Total 6gm per Banana plant). The inevitable ‘burn’ happened one hot noon and the farmer was advised to stop fertigation and asked to irrigate the plant copiously.

Pictures taken on 01/09/2011 at his field (Uthamapalayam, Theni District, Tamilnadu) are published here above.

Remedy:

Irrigate copiously to leach (wash out) the excess chemicals from the soil.

Regards,
A.Vishnu Sankar

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Posted in: 38. Fertilizer burn - Effect of excessive use of chemical fertilizers

Effect of excessive dose of MKP and Urea when used them for banana bunch development

Dear reader,
 You are kindly requested to visit the link: 

 "Banana Bunch Care and procedures to maximize the bunch size", 

which is a must read article that covers all aspects of bunch care and proven methods to increase the bunch size, before commence reading the following article. Thank you.

A case of excessive dose of MKP and Urea when used them for banana bunch development and its detrimental effect:

The two pictures shown here under were taken at a field where the farmer was asked to spray 0.5% MKP (Mono potassium phophate) + 1% Urea on bunches for bunch development. This wrong selection and overdose of chemicals has resulted in total spoilage of the bunch due to abnormal elongation of fingers (11 to 12 inches) and very thin fingers with no scope for further development. (See the lesions in the peduncle). 

To avoid damage to the developing Banana bunch learn to use fertilizers judiciously.

At the banana bunch development stage the following fertilizers are  normally recommended to enhance the size of fruits / bunch: 

Option 1: Application of 2% (20gm / 1litre) Potassium sulphate (0:0:50) as foliar spray on bunches, two times with 15 days interval.

(OR)

Option 2: Application of 1% (10gm / 1litre) Potassium nitrate (13:0:45) as foliar spray on bunches, two times with 15 days interval.

(OR)

Option 3 (Considered as best since it addresses all nutritional deficiencies): Application of 0.5% (5gm / 1litre) Potassium nitrate (13:0:45) + 0.5% (5gm / 1litre) of foliar grade Micro nutrient mixture as foliar spray on bunches as first spray followed by a second application of 2% (20gm / 1litre) of Potassium sulphate (0:0:50) + Biozyme 2ml / 1litre after 15 days. Repeat the second one again as III application after 15 days interval.

Important Note 1: In all the above applications you can also add 0.2% Bavistin (Fungicide) for prophylactic control of fungal infections. Use wetting agents also. 

Important Note 2: Nowadays farmers are going for a minimum of four applications within a period of 60 days (4 sprays with 15 days interval between each spray) and are getting very good results. 

Precautions: 

• Care should be taken to spray the above fertilizers only after all the hands are fully opened and after sufficient extension of male flower bud in the rachis. 
• Do not apply any fertilizers or pesticides 15 days before harvest since there is a possibility of the unabsorbed chemical residues entering human food chain.
• Application of excess dosage of fertilizers, Enzymatic and synthetic Growth promoters and plant protection chemicals on bunches are to be strictly avoided.

Good quality bunches that were sprayed with SOP, Multi K, foliar grade M.N and Biozyme solution. Please visit the following links also:  "Banana Bunch Care and procedures to maximize the bunch size",  'Banana bunch care as recommended by ICAR'.

Regards,  A.Vishnu Sankar

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Posted in: 26 a. Banana Bunch care - Effect of excessive use of chemicals

Effect of excessive dose of Hexaconazole fungicide (Contaf) on Banana

Effect of excessive dose of Hexaconazole fungicide (Contaf) on Banana:

Hexaconazole is a systemic, broad-spectrum fungicide mainly used on banana. It is widely used to control rhizome rot, corm dry rot and root rot in banana and the application rate is 1ml to 1.5ml per plant for rootzone drenching. Application of the above fungicide @1ml in 200 ml of water for drenching around the plant is enough for a month old plant, 1.25 ml in 500 ml for 2 months old and 1.5 ml in1litre for plants above 3 months.

Here in the two pictures published here below, the injury caused to the the outer layers of the pseudo stem and the leaves is because of the root-zone application of Hexaconazole @ 6ml / 1litre for 3 month old plants by the farmer by mistake. Banana plants collapsed fully in places where he applied 2 litre of the above solution.

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Posted in: Injury due to Fungicide - Effect of wrong selection and excessive use of fungicide

Injury due to Gramoxone herbicide spray on Banana

Injury due to Gramoxone herbicide spray on Banana: 

The pictures published down here under show injury to banana plants due to spraying of Gramoxone herbicide without spray hoods. During herbicide application, whether it is Gramoxone or Glyphosate, the following precautions should be taken:

1. Use only recommended dose of herbicide. 
2. Use spray nozzles that are specially designed for weedicide / herbicide application. 
3. Apply them under low pressure. 
4. Do not speed. A slow move, slower than the normal leisurely walk is the ideal speed for herbicide application. 
5. Use spray hoods mounted on spray nozzles to prevent the herbicide product to escape and cause crop injury. 
6. During spraying the spray hood should be as close to the ground as possible make sure the hood is on the ground until it has fully moved past the plant. Raise the hood only after turning off the spray.
   Regards, 
   A.Vishnu Sankar

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Posted in: 42. Herbicide Injury - Effect of wrong selection and excessive use of Herbicide

Copper (Cu) deficiency symptoms

Copper (Cu) deficiency symptoms:

• Leaf mid rib and veins bend backwards resulting in umbrella shape appearance of the plants.
• Leaves appear yellow-bronze in colour.

Control Measures:

1. Spray copper sulphate @ 2g/l of water (neutralized with lime) at weekly interval for 2-3 weeks.

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Posted in: 37. Copper (Cu) deficiency symptoms

Zinc (Zn) deficiency symptoms

Zinc (Zn) deficiency symptoms:

• Narrow pointed and chlorite young leaves, bunchy top crowns are the symptoms of zinc deficiency which is often falsely identified as BBTV by the farmers.
• The young emerging leaves have high amount of anthocyanin pigment on the lower side of the leaves, which often disappears as the leaf unfolds.
• Leaves are narrow with yellow to white stripes between the secondary veins.
• Later on oblong, brown or necrotic patches develop on the yellow striped areas.
• The leaves of the young suckers may become distorted, comprising of mid-rib and serrated narrow lamina only.
• Bunches developing on such plants have twisted fingers with prominent light green tip.
• The characteristics symptoms appear in young leaves which become significantly smaller in size and more lanceolate in shape.

Control Measures:

1. Manual application of Zinc sulpahte @ 2g/plant.

                                                (OR)

2. Spray chelated Zinc @ 2-3 g/1 of water at 7-10 days interval till deficiency symptoms disappear.
3. For ratoon crop apply the above preparation 45 days after cutting the mother plant.

The bunchy top crowns shown in the picture below are the symptoms of zinc deficiency which is often falsely identified as BBTV by the farmers.

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Posted in: 36. Zinc (Zn) deficiency symptoms

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

Manganese (Mn) deficiency symptoms

Manganese (Mn) deficiency symptoms.

• Plants exhibit “comb-tooth” leaf chlorosis and the presence of fungus- Deightoniella torulosa in the chlorotic areas.

• The chlorosis starts from the leaf margins and spreads along the veins towards the midrib with interveinal areas remaining green, hence the comb-tooth appearance.

• Leaves desiccate prematurely causing poor fruit development.

• Normal size bunch is produced by the plant but the fruits are covered with black spots.

Control Measures:

a.      Spray Manganese sulphate @ 2 g/l of water ( Neutralized with lime)once a week for two weeks.

Photos courtasy: TNAU, Coimbatore, Tamilnadu, India.

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Posted in: 35. Manganese (Mn) deficiency symptoms

Calcium (Ca) deficiency symptoms

Calcium (Ca) deficiency symptoms:

• Young leaves show interveinal chlorosis near the margins and towards the tip. 
• When these chlorotic patches die they create a serrated necrosis along the leaf margin. 
• A temporary shortage of calcium causes the “spike leaf” symptoms in the field in which the lamina of new leaves is deformed or almost absent with thickened lateral veins near the mid-rib and deficient root system which is susceptible to rot. 
• Fruit quality is inferior and the peel splits when the fruit is ripe.

(Boron and Calcium deficiency symptoms tend to overlap. So see Boron deficiency pictures also).

Picture 1: Ca deficiency-Early foliar symptom - 
Yellow stripes parallel to leaf midrib.

         
Picture 2:  Ca deficiency-Early foliar symptom - 
Yellow stripes parallel to leaf midrib.

        Picture 3: Early foliar symptom of Calcium and Boron deficiency -           WRINKLED LEAF.

        

          Picture 4: Boron & Calcium deficiency - deformed and whitish heart leaf. 

        
Picture 5: Boron and Calcium deficiency - "SPIKE LEAF" (in which the        lamina of new leaves is deformed or almost absent). 

 

(Photos credit: ctahr, Hawaii)

Control Measures:

         

a.     Drip fertigation of Calcium Nitrate (CaNo3) @ 4 kg/1000 plants every 4^th day upto 5^th month.

                                                (OR)

b.     Manual application of Calcium nitrate (CN)) @ 40g/plant per month upto 5^th month and if necessary till finger development. Application of CN  provides calcium as well as nitrogen (15.5-0-0 + 19% Ca) to the soil, therefore quantity of nitrogen needs to be adjusted with the total nitrogen requirement of the soil.

The picture below shows a plant affected due to Calcium and Boron deficiency and the subsequent recovery after the remedial measures taken as under:

Step 1: Drenching the growing shoot (by applying inside the emerging unfurled funnel shaped leaf) with 100 ml of foliar grade boron rich micronutrient solution.

Step 2: Fertigation of Calcium Nitrate @ 20 gm / plant (in 2 split doses).

Note: If the deficiency is severe, 3 to 4 foliar applications of micronutrients have to be given to the crop up to 7 months along with fertigation of Calcium Nitrate @ 75 gm / plant in 5 to 7 split doses.

 

Sources of Calcium:

Lime

Soil amendment which is commonly used to raise the pH of the soil.

Calcium Carbonate

Approximately 38% Ca, depending upon its source

A common liming material, calcium carbonate also supplies calcium to the soil.

Dolomite

22% Ca and 12% Mg, depending upon the dolomite source

In addition to raising the pH, dolomite is a source of calcium and magnesium.

Gypsum

23% Ca and 19% S

Unlike liming materials, gypsum does not increase the soil pH.

In addition to providing calcium and sulfur, gypsum may be used to correct soil physical problems and/or aluminum toxicities.

Calcium nitrate

15% N and 20% Ca

Calcium nitrate is very soluble in water.

Superphosphates

Single (SSP)

18-21% Ca

SSP supplies both calcium and phosphate.

Triple (TSP)

12-14% Ca

Like SSP, TSP supplies both calcium and phosphate

Regards,
A.Vishnu Sankar

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Posted in: 30. Calcium (Ca) deficiency symptoms