Nutrients

N Nitrogen
P Phosphorus
K Potassium
Mg Magnesium
Ca Calcium
B Boron
Fe Iron
Mn Manganese
Zn Zinc
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Grapevines - Number reduced

Symptoms
P deficiency reduces fertility and fruit setting considerously, resulting in poor yield.

Causes
Phosphorus deficiency

Grapevines - Discolouration

Symptoms
P deficiency results in reduced growth and dark green leaves, often with some bronzing to purple lesions on the leaf blades. Discoloration starts at the margins and spreads over the interveinal areas. The leaves become hard and stiff. Dormant buds contain only small flower primordia what reduces the performance of the vines.

Causes
Phosphorus deficiency Phosphorus deficiency occurs rather seldom in the fields.

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

  • Healthy green foliage
  • Improved fruit set
  • Improved quality

Yara recommended fertilisers for Phosphorus deficiency

YaraVita FOLIAR POTASH

YaraVita FOLIAR POTASH

Grapevines (Wine Grapes only): 3 to 5 l/ha at fruit set, pea-sized berries and first colour softening. Water rate: 200 to 500 l/ha.

Read more about YaraVita FOLIAR POTASH

YaraVita SENIPHOS

YaraVita SENIPHOS

Grapevines: 10 l/ha at fruit set and repeated 2-3 times at 10-14 day intervals. Water rate: 500 l/ha.

Read more about YaraVita SENIPHOS

Other recommended products

YaraMila COMPLEX
YaraMila COMPLEX
Grapevines: 100 kg/ha applied as a top dressing after at start of Spring regrowth. For more detailed advice on rates and timings contact a Yara fruit specialist.