Potato Review Group

Contents

Background

Uptake of calcium

Influence of calcium in reducing stress to plants

Application of calcium

Further information:

Calcium notes

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Background

  1. Calcium is required during early stages of tuber formation and a deficiency may restrict the number of tubers formed. More …
  2. Calcium deficiency results in loss of membrane integrity and cell necrosis (as internal rust spot in tubers); other internal tuber necrotic disorders may also result from calcium deficiency and tubers are more susceptible to rotting diseases.
  3. Calcium has little mobility in phloem or from cell to cell and concentrations in tubers are very low.
  4. The concentration of calcium in tubers declines throughout the season.
  5. Calcium can be transported out of tubers more easily than in to tubers and there may be loss of calcium from tubers under dry conditions, when water may be lost from tubers to foliage.

Use this link for more information on mobility of calcium and influence on internal rust spot.

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Uptake of calcium

  1. High rates of potassium application may reduce total uptake of calcium by potatoes but there appears to be little influence on the concentration of calcium in tubers.
  2. The rate of calcium uptake declines as tubers grow, unlike other nutrients which may show a “peak” rate of uptake during rapid canopy growth. More …
  3. Application of calcium to foliage generally has little affect on the concentration in tubers and thus on internal rust spot. However, application of calcium may reduce loss of calcium in stress situations.

Use this link for more information on calcium uptake and interaction with other nutrients.

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Influence of calcium in reducing stress to plants

  1. Calcium is suggested to mitigate stress in plants.
  2. Application of calcium has been shown to reduce damage to potato leaf cell membranes during heat stress.
  3. Tuber calcium concentration may decline when plants are drought stressed but increase again when water becomes available. More …
  4. A reduction in water loss during drought stress has been shown to:
    • increase the concentration of calcium in potato tubers.
    • reduce the incidence and severity of internal necrosis of potato tubers (see Internal rust spot)

Use this link for further information on calcium and stress reduction.

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Application of calcium

  1. Calcium may be applied as lime (CaCO3) to increase pH in low pH soils.
  2. However the optimum pH for potatoes is about pH 5 – 5.5.
  3. Increasing soil pH can increase the risk of common scab infection.
  4. Therefore lime should not be applied before potatoes.
  5. Foliar application of calcium products such as phosphite + calcium can help to maintain foliar calcium in stress conditions and reduce loss of calcium from tubers.

See also Calcium chemistry.

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Further information

Calcium notes

Calcium and magnesium 2018 (Measurement of calcium in soil; importance for soil structure; interaction with other nutrients)

Cytokinins, calcium and tuberisation 2015 (Calcium nutrition during stolon development is important for tuber formation)

Calcium phosphite application 2012 (Calcium physiology; further experiments on calcium phosphite application to foliage)

Foliar nutrient applications 2011 (Includes experiment showing beneficial effects of calcium phosphite application to foliage)

Nutrient interactions 2010 (Includes: calcium physiology; interactions between calcium and other nutrients in soil)

Calcium content of tubers 2001 (Movement of calcium into and out of tubers)

Internal rust spot 2000 (Calcium may be lost from tubers in stress conditions)

Internal rust spot 1998 (Low concentration of calcium in tubers increases the risk of internal rust spot)

 

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