Prevent blossom-end rot with the right nutritional strategy

Blossom end rot (BER) is one of the most common physiopathologies in crops such as tomatoes and other solanaceae (e.g. bell pepper).

The physiopathology brings both morphological and chromatic malformations in the fruits. The damage normally appears in the form of a lesion in the distal apex of the fruit, due to the necrosis of the tissues, which makes the fruit non-marketable.

Blossom end rot in tomatoes is caused by a calcium deficiency, which is a low-mobile element in plants. The calcium is translocated with difficulty inside the fruit, both in its first developmental phases and after the beginning of veraison.

In order to prevent blossom end rot in tomatoes, Grenn Has Italia suggests the following nutritional strategy, on top of the agronomic_suggestions.

Foliar treatments

–  To increase the efficiency of the root apparatus, which plays a fundamental role for optimal transport of calcium.

   Algaren Twin to stimulate the constant regeneration of root capillitium and to increase setting.

–  To provide a high quantity of calcium directly to the fruit.

Foliar applications also directly on the fruit, starting from the setting of the first stage and every 8-12 days with Calboron, with a high content of readily-absorbable calcium (CaO 30%)          complexed by high quality carboxylic acids, guaranteeing its high bioavailability.


–  To integrate calcium and nutrients via the roots without creating vegetative excesses

Fertirrigation with the Calfon Line

From pre-flowering until the end of setting of the first stage use Calfon P, ideal in the first   developmental phases when there are no fruits, due to the presence of ammoniacal nitrogen   (2,5%) and of phosphorus, as support for the development.

Use Calfon until harvest of the first stage and subsequently Calfon K, both formulated   without   ammoniacal nitrogen to stimulate the absorption of calcium and its translocation in   the fruits.




For organic farming the containment of this physiopathology is based on indirect methods, since no calcium can be supplied to the fruits.

Green Has Italia recommends:

  • Algaren Twin associated with Borogreen L (via foliar application): at the beginning of flowering of each stage to stimulate the constant regeneration of root capillitium, to increase setting with the resulting number of seeds per fruit, in order to increase the translocation of calcium towards the fruits.
  • Vit-Org VG in fertirrigation. Its application acts directly against thermal and water stresses, stimulates the humification of the organic matter of the soil, creating the favourable conditions for a higher availability of all nutritional elements, therefore also of calcium, promoting the metabolic activities of the plant.