Apple tree cultivation has currently reached a very high technification level, with highly demanding quality standards.

For apple trees to obtain high, quality and constant yields over time, they need the supply of #microelements throughout their cycle. Especially in order to accumulate enough reserves to overcome winter dormancy.

INPROG develops specific fertilisers for apple trees, which provide them with a balanced nutrition to be able to produce in terms of quantity and quality without alternate bearing.


Bitter pit

One of the biggest challenges in apple growing is the reduction or elimination of BITTER PIT.

The keys to reduce this disease are as follows:

  • Controlling vigour throughout the cycle, especially at the end of winter, helps the calcium absorbed by the plant to be allocated to the fruit. Thus, we reduce the incidence of bitter pit.
  • Antagonistic cations: Unbalanced soils in terms of potassium, magnesium, sodium or iron hinder calcium absorption by the plant. Structured and balanced soils facilitate good calcium absorption.     
  • Available calcium: Most of the calcium contained in the soil is not available to the apple tree. FORTEC and NUBIECOL contain calcium bound to organic matter, which improves root uptake.

FORTEC and NUBIECOL contain calcium bound to organic matter, which improves root uptake. Moreover, their organic nitrogen content naturally regulates the vigour of the tree, hence improving calcium absorption.


These three parameters are sought after in apple orchards:

  • Calibre increase: A balanced N-P-K fertilisation, together with the supply of all #microelements and essential elements (#FRpower), activates the primary and secondary metabolism, resulting in higher calibres.
  • Production stability: The supply of the #microelements sulphur and extended-release organic nitrogen increases the tree's reserves for winter dormancy. These reserves have a direct impact on ensuring fruit set and preventing flower and fruit drop. 
  • Strengthening of natural defences: These defences depend on the supply of #FRpower #microelements and essential elements, which stimulate and activate the compounds that act as natural defences. Healthy nutrition.  

Key nutrients

In apple tree growing, four nutritional elements are key to high yields:


Low calcium contents cause the appearance of bitter pit and have an impact on fruit firmness.


Low sulphur content in the soil leads to lower chlorophyll content and reduced fruit colour (polyphenol production).


Zinc deficiency reduces the crop’s yield potential. Low levels considerably reduce the production capacity of complex sugars as well as calibres.


One of the key nutrients for the correct nutrition of apple trees is potassium, which also impacts Brix levels and colour.

The FORTEC-FR and NUBIECOL ranges naturally contain a large amount of these 4 elements, thus providing an easy, direct and efficient solution for apple tree fertilisation.

Prevention of nutritional deficiencies

In most cases, nutritional deficiencies become visible when the condition is severe. Prior to this, the crop has already undergone stress, which has a direct impact on the yield. It is very important that the most scarce or least available nutrients are always available from the onset of the vegetative cycle.

In the case of apple trees, these are the following:

  • Calcium
  • Iron
  • Zinc
  • Manganese
  • Sulphur
  • Silicon

The annual supply of FORTEC-FR and NUBIECOL fertilisers guarantees the correct nutrition of the crop, thus preventing visible or non-visible nutritional deficiencies. The annual supply of all the essential minerals bound to a stable organic matter of noble origin (#multifem) is crucial.

Cumulative effect

The supply, year after year, of the FORTEC-FR and NUBIECOL products improves production both in terms of calibres and kg/ha. This is the conclusion obtained in a trial at IRTA-Mas Badia.

This increase is due to the accumulation of #microelements and essential elements available to the plant. This allows the plant to regulate itself and produce more and better.

Fertiliser benefits

For cultivation

  • Reduction of alternate crop
  • Prevention of
    nutritional deficiencies.
  • Increased fruit set.
  • Decrease in
    bitter pit condition.
  • Vigour regulation.

For the farmer

  • Reduction
    of pruning time.
  • Incorporation of
    assimilable calcium.
  • We provide a large amount
    of #microelements and
    essential minerals. #FRpower
  • We facilitate the management of
    N-P-K fertilisation.

For harvesting

  • Higher calibres.
  • Easier to obtain a
    better colour.
  • Increase in Brix degrees.
  • Increased firmness.

Related products

F-FR Vipo

Organomineral fertiliser for apple and vine growing. It is a single-application fertiliser according to the quantities applied.

F-FR Complet

Organomineral fertiliser for crops with high potassium and sulphur requirements, together with calcium, microelements and organic matter.

F-FR Standard

Organomineral fertiliser for crops with high potassium requirements, together with calcium, microelements and organic matter.

F-FR Alfa

Organomineral fertiliser specially formulated and designed for the supply of complexed potassium, microelements and organic matter.


Organomineral fertiliser intended for the implantation of all types of crops, especially fruit and woody crops.


Premium organic fertiliser made from a selection of manures to obtain a superior product.

Verfor basic

Organic fertiliser from composting manure from controlled and selected farms.

Verfor basic+s

Organic fertiliser from the ripening of our #starter with bicalcium phosphate.


Organic amendment from composting cattle manure.

Nubiecol orgánico

Group of organic fertilisers formulated and designed for crops with high potassium requirements.

Nubiecol C

A family of organic fertilisers formulated and designed to achieve high-yield organic crops.

Organic composted manure

Ecological organic fertiliser manufactured as the base of our developed ecological fertilisers. #ECOstarter


Ecological organic fertiliser. From composting cattle manure, it is suitable for all crops.

Do you need more information?

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Ask our technical support.

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