Nutrients

N Nitrogen
P Phosphorus
K Potassium
Mg Magnesium
Ca Calcium
S Sulfur
B Boron
Fe Iron
Mn Manganese
Zn Zinc

Banana - Chlorosis

Symptoms
Slow, stunted growth with 'rosetting' appearance. Thin and woody stems; petioles break easily. Broad longitudinal chlorotic bands with necrotic spots may occur on both sides of the midrib or along the leaf edge. Marginal necroses on oldest leaves coalesce, resulting in premature senescence. Younger leaves may show bluish to purple tint, especially on backside.

Reasons
Phosphorus deficiency. Excess nitrogen fertilization also leads to a blue-green color of the leaves. Manganese deficiency also causes marginal necrosis, but these have a darker color.

Banana - Growth retardation

Symptoms
Slow, stunted growth with 'rosetting' appearance. Thin and woody stems; petioles break easily. Broad longitudinal chlorotic bands with necrotic spots may occur on both sides of the midrib. Marginal necroses on oldest leaves coalesce, resulting in premature senescence. Younger leaves may show bluish to purple tint, especially on backside.

Reasons
Phosphorus deficiency

Banana - Chlorosis

Symptoms
Slow, stunted growth with 'rosetting' appearance. Thin and woody stems; petioles break easily. Broad longitudinal chlorotic bands with necrotic spots may occur on both sides of the midrib. Marginal necroses on oldest leaves coalesce, resulting in premature senescence. Younger leaves may show bluish to purple tint, especially on backside.

Reasons
Phosphorus deficiency

Banana - Discolouration

Symptoms
Slow, stunted growth with 'rosetting' appearance. Thin and woody stems; petioles break easily. Broad longitudinal chlorotic bands with necrotic spots may occur on both sides of the midrib. Marginal necroses on oldest leaves coalesce, resulting in premature senescence. Younger leaves may show bluish to purple tint, especially on backside.

Reasons
Phosphorus deficiency

Phosphorus deficiency made worse by

  • Acidic or very alkaline (calcareaus) soils
  • Low organic matter
  • Cold or wet conditions
  • Crops with a poorly developed root system
  • Soils with low P reserves
  • Soils with a high phosphate capacity
  • Iron rich soils

Phosphorus is important for

  • Part of nucleic acids, phospholipids and energy storing and transferring systems in plants
  • Important for root growth, flower development and fruit set