Calcium for the Commercial Grower

The Importance of Calcium

Grower’s have long realised the importance of Calcium availability at relevant growth stages, to achieve the crop’s maximum potential by increasing the health of the plant and the quality of the fruit. Calcium dense produce is firmer and crunchier with improved storage quality and shelf life.

Many plant diseases are associated with low Calcium status, and many physical disorders of crops can be attributed to Calcium deficiency. This usually causes visible abnormalities in growing parts of plants and can cause hidden issues with dieback of roots.

Roots Shoots & Fruits specialise in plant mineral nutrition and biological organisms, working closely with NZ growers to analyse their leaf tissue tests and prescribe plant nutritional programs to improve crop health and production.

The supply of calcium may be limited to your plant during a critical growth phase, for a few reasons; Stressful conditions such as drought and very hot weather, winds that dry out plant tissue, soil that contains an abundance of magnesium or potassium which calcium competes for uptake with, excess nitrogen or plants that simply grow too fast for the roots to keep up with the calcium supply. And of course, maybe there simply isn’t enough calcium in the soil. For these reasons foliar adjunctive calcium applications are critical in horticulture.

Listed below are some common disorders widely seen in calcium-deficient crops:

  • Fruit pitting in Kiwifruit
  • Blossom end rot of tomatoes and capsicum
  • Albeda breakdown in citrus
  • Bitter pit in apples
  • Hollow Heart, known as ‘Browning’ in potatoes
  • Fruit splitting and cracking – especially after rainfall
  • Dieback of growing shoots and roots
  • Irregular cropping is also caused by calcium deficiency
  • Poor post-harvest ‘keeping quality’ of fruit, primarily the fruit skin quality
  • Plants susceptible to pests and disease due to weaker cells from a lack of calcium.

RSF believe that taking plant tissue samples for Balanced Analysis early in the season, three weeks pre-flower for most crops where possible, is essential in horticulture before beginning any foliar fertiliser program. This allows growers to best ascertain the current levels of elements and the nutrient requirements of the crop ensuring correct allocation of funds for a return on investment.

Calcium is usually applied after fruit set because, as a high growth phase, it will assist in the cell division process and reinforce the fruit cell membrane–encouraging firm, thick celled fruit.

Comprehensive trials (on Apples, Grapes, Berry crops, Stonefruit, Kiwifruit etc) have been conducted over the last two decades in NZ and other countries,  comparing the use of various Calcium fertiliser treatments and the impact they have on the calcium levels in the fruit and the ROI for the growers. View a library of research papers at http://www.rd2.co.nz/trials/

Are all Calcium products equally effective?

Biomin Calcium has come out favourably in most instances when compared to generic calcium applications and the reason is clear. Calcium is naturally a very immobile element. Plants find it hard to absorb without a lot of work, and then find it hard to move throughout the plant’s system.

Biomin Calcium is completely soluble and highly bio-available. This is because the Calcium molecules are ‘chelated’ with Glycine. Glycine is the smallest amino acid and what plants themselves are made of, therefore plants recognise and absorb the Glycine chelated molecules readily sending it to areas of need within the plant. In Kiwifruit trials, the fruit treated with Biomin Calcium had a 15% increase in residual Calcium levels, showing that Glycine chelated Calcium is highly systemic as well as mobile through the fruit cuticle, a characteristic not present in other calcium formulations in the marketplace.

The advantages are numerous; lower application rates and fewer applications of the fertiliser is needed, because the plants uptake the mineral more effectively resulting in higher quality fruit and plants more resistant to pests and disease. Biomin calcium is non-phytotoxic whilst chloride applications are, this means Biomin can be applied at higher rates if required without the worry of burn, so less tractor runs. Biomin is totally absorbed by plants within a few hours of application, creating a great rain window for grower operations. The added bonus is that Biomin fertiliser is organically certified through Biogro, meaning safe applications that are beneficial for the environment and the microorganisms present in our soils.

Foliar spray Biomin Calcium  during cell division or at times of plant growth and notice:

  • Less disease and deficiency symptoms as listed above, PLUS
  • Juicier and more colourful fruit
  • Less fruit splitting after a heavy rain
  • Crunchier fruits such as grapes and apples with stronger plant parts
  • Calcium also acts as a detoxifying agent by binding up the toxic compounds it comes across.