Avocado cultivation is highly technical and has currently reached a very high level, with very demanding quality and production standards.

The well-managed avocado tree is a highly productive crop and, at the same time, highly extractive in terms of nutrients.

For the apple tree to obtain high, quality and constant yields over time, it needs the supply of #microelements throughout its 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 beginning 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 make it difficult for the plant to absorb calcium. 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 fertilisation in terms of N-P-K, together with the supply of all the #microelements and essential elements (#FRpower), activates the primary and secondary metabolism, thus achieving higher calibres.
  • Production stability: The supply of #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 growing, there are four nutritional elements that are key to obtaining high yields.


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


Low sulphur contents in the soil lead to lower chlorophyll contents 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 crop’s correct nutrition, thus preventing both visible and 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.

Do you need more information?

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Ask our technical support.

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