Toxicity effects of excessive use of ferrtilisers in Banana crop

                                     

 

Nitrogen  :

Excess vegetative growth, Crop less hardy, leaves dark green, root growth less.

Delayed maturity, bunches break prematurely, leaf lamina burn if moreurea sprayed.

 

Phosphorous  :

Deficiency of Zn, Fe, Mn  as well as Ca and Mg.

 

Potash :

Due to imbalance of cations deficiency of Ca and Mg.

In banana imbalance of K and Mg ratio gives Ca and Mg deficiency.

 Crop looks bluish green.

 

Calcium :

   Normally  Ca toxicity do not appear but excess Ca gives K and Mg deficiency.

 

Magnesium :

Like Ca the toxicity of Mg also do not appear but due to imbalance in K, Ca and Mg levels crop growth is reduced if Mg is high.

 

Sulphur :

Reduced leaf size, stunted growth, leaf lamina looks scorched and  leaves show yellowing in middle part.

 

 

In case of toxicity of micronutrients untimely yellowing, scorching of leaves, leaf drop, reduced root growth and less uptake of nutrients are seen.

 

Manganese :

Deficiency of Zn and Fe. Leaves yellowish, new growth yellow, leaves look rusted, brown, dark orange colored.Growth rate and vigor less. Mn toxicity is seen more in acidic soils.Mn quantity if comes to 76,000 ppm, Ca absorption is reduced by 30 %, Mg absorption is reduced by 40 % and Zn absorption is reduced by 20 %. Fruits ripening is imbalanced  and do not show uniform ripening.

 

Zinc :

Yellowing of crop. Induce Fe deficiency, saplingsmortality.

 

Iron :

Fe do not exhibit toxicity but it induces Zn toxicity.

Small brown spots are seen on leaves.

Excess use of  Fe chelates is harmful to crop.

Hence care must be taken while giving fertilizers.

 

Copper :

Induced Fe deficiency, root growth is stunted. Reduced branching ,yellowing.  Rootsshow dark colour and become thick, stunted plant growth.

 

Boron :

Tips of leaves yellowish and leaves show necrosis.

 

Molybdenum :

Discoloration of leaves (light colour).Leaves lamina and tips show scorching, leaves become yellow, torned, reduced size of leaves.Crop growth rate is reduced, stunted growth of suckers and no proper filling of fruits.

 

Sodium  :

Nutrients imbalance if Na is high.If irrigation water has high Na and Mg then K absorption is reduced even if K is adequate in soil.Micronutrients absorption also get affected.Banana crop is more sensitive to excess of salts and sodium. When soil has chloridemore than 500 ppm then adverse effects of salt  are seen. Under such cases the use of Agriplex OA is beneficial.