Nutrients

N Nitrogen
P Phosphorus
K Potassium
Mg Magnesium
Ca Calcium
S Sulphur
B Boron
Cu Copper
Fe Iron
Mn Manganese
Mo Molybdenum
Zn Zinc

Potatoes - Dark green color

Symptoms
Shoots are upright and thin with dull, dark green leaves. Margins of leaves are cupped upward. Growth is stunted.

Reasons
Phosphorus deficiency (left)

Potatoes - Growth retardation

Symptoms
Lateral root development is inhibited. Tuber yield will be reduced.

Reasons
Phosphorus deficiency (right)

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

  • Increased number of tubers
  • Produces tubers of uniform size
  • Boosts bulking and increases the yield of tubers
  • Increases tuber dry matter content and starch levels
  • Improves storage potential of tubers and reduces storage diseases

Yara recommended fertilizers for Phosphorus

YaraVita MAGPHOS K

YaraVita MAGPHOS K

Potatoes: To increase tuber number, 10 l/ha at tuber initiation (when 50% of the tip swellings are twice the diameter of the rest of the stolon). To increase tuber size a minimum of 2 applications of 5 l/ha or 1 to 2 applications of 10 l/ha during tuber bulking (as soon as first formed tubers are 10 mm in diameter). Allow 10-14 days between applications. Water rate: 200 l/ha

Read more about YaraVita MAGPHOS K

YaraVita SENIPHOS

YaraVita SENIPHOS

Potatoes: Apply Seniphos at 15 l/ha in 200 litres of water, at the onset of tuber initiation. The application may be repeated at bulking, using 5 l/ha in 200 litres of water repeated at 2-3 week intervals.

Read more about YaraVita SENIPHOS

Other recommended products

YaraVita CROPLIFT PRO
Potatoes: 2.5 to 5 kg/ha. Repeat at 10 to 14 day intervals as necessary. Water rate: 200 l/ha.
YaraVita MAIZE BOOST
Potatoes: To increase tuber number: 10 l/ha at tuber initiation (when 50% at the tip swellings are twice the diameter of the rest of the stolon). To increase tuber size: a minimum of 2 applications of 5 l/ha during tuber bulking ( as soon as first formed tubers are 10mm in diameter) and following petiole analysis during tuber bulking. Allow 10 to 14 days between applications. Water rate: 200 l/ha.