Healthier vegetables with targeted fertilization

The high level of specialization that characterizes horticultural companies involves a series of technical and cultural peculiarities that make land management an important and focal element in horticulture. At the same time, fertilization also plays a leading role due to the need to properly nourish various crops. Combining adequate soil management with targeted fertilization has positive effects on product quality and plant health, resulting in the decreased use of pesticides, benefits for the environment and fewer residue issues.

According to Ismea, in 2019 in Italy horticultural crops were grown over an area of approximately 450,000 hectares. The tomato (for fresh-consumption and industrial use), the potato and the artichoke form the lion’s share in our country, followed by numerous other species (grown in much more limited areas) such as lettuce, cauliflower, fennel, carrot, melon…

In reality, the world of horticultural crops is extremely varied and broad, characterized by very different needs in terms of cultivation technique and qualitative characteristics required by the market.

Horticultural crops can in fact be divided as follows, according to the edible part of the plant:

• seeds: bean, pea, chickpea;
• roots: carrot, potato, onion;
• stems: fennel, celery;
• leaves: spinach, radicchio, lettuce, salads
• flowers: asparagus, artichoke, cauliflower, broccoli;
• fruit: cucumber, courgette, tomato, bell pepper, melon.

Whether they are intended for fresh consumption or processing, horticultural crops must comply with qualitative parameters that will set the placement price range on the market and consequently profitability. These parameters are extremely variable depending on the type of vegetable.

Some examples?

If consistency, colour, transport resistance and dry matter are of primary importance with industrial tomatoes, with fresh-consumption tomatoes an added salient feature is flavour. In the case of potatoes, in addition to the size and uniformity of the shape of the tuber, the dry matter content and reduction of sugars is also important, as well as the greater or lesser predisposition to enzymatic browning. Furthermore, in the case of melon, in addition to the uniformity of size, other characteristics pursued include adequate sweetness and consistency of the pulp and aromatic intensity, as well as the content of carotenoids and polyphenols, by virtue of their appreciated antioxidant properties.

On the other hand, the need to comply with the European standards on MRLs, or Maximum Residue Limits of active substances contained in pesticides, has a more general value for horticultural crops.

Annex I of Regulation 396/2005 – which has undergone several updates over time – reports the official list of food products which the MRLs apply to.  It goes without saying that the presence of any chemical residues in vegetables is closely linked to the defense strategy adopted.

There are numerous biotic adversities that can cause quantitative and qualitative damage to horticultural crops, attacking both the aerial (leaf system and fruits) and the hypogeal (tubers, bulbs, taproots) parts of the plants.

Among the main ones are:

• fungal diseases such as downy mildew, botrytis, powdery mildew, alternaria, septoriosis, fusariosis, verticilliosis, rhizottoniosis, cladosporiosis… ;
• bacterial diseases such as cancers, rot, brown spot, speckling… ;
• viruses such as the mosaic virus in tomatoes, zucchinis, cucumbers…

The mentionable among the parasites instead, are insects belonging to numerous families such as Aphids, Rhynchota, Lepidoptera, Hymenoptera and Coleoptera, but also Acarus (like small spiders) and Nematodes.

Finally, abiotic adversities should not be underestimated, such as specific physiopathies linked to nutritional imbalances, like apical rot (tomato and zucchini), splits and micro-element deficiencies.

As with all agricultural crops, proper agronomic management, both in the open field and in covered crops, also plays an essential role with horticultural crops in guaranteeing quality and yields, but especially in preventing serious phytopathological problems.

Crop rotation is among the most important agronomic practices (without exhausting the subject) for containing the spread of pests and diseases, since it demotes the proliferation of pathogens and parasites.  The use of any crop covers serves the same purpose, which can also positively influence the soil’s endowment in organic matter and nutrients and counteract the development of certain harmful microorganisms (as is the case with Brassicaceae) and weeds, thus reducing the need for external inputs for fertilization, defense and weeding.

The porosity of soil, closely linked to organic matter content and sometimes put to the test by frequent passages with machines and equipment, also plays a fundamental role in creating an environment conducive to the health and efficiency of hypogeal systems, as well as in promoting a microbiological biodiversity that reduces the possibility of giving pathogens the upper hand.

Fertilization must take into account not only generic nutritional needs (nitrogen and magnesium, for example, which are essential for a good production of leafy vegetables), but also potentially specific needs: sulphur, for example, is a central element in the nutrition of garlic, onion, cauliflower, cabbage and asparagus.

With three products from the Terrapiù line, Agribios meets the efficient and sustainable management needs of horticulture, with the objective of preserving and/or creating better soil conditions that welcome vegetable, and that positively influence the nutritional as well as the phytosanitary state of plants.

AGRI BIO AKTIV is a soil regenerator that, in addition to providing organic matter and nutrients, promotes and directs the proliferation in the soil of microorganisms useful for the development of plants. Its particular microbial composition, rich in Trichoderma, acts on the soil and the roots, limiting, via antagonism, the development of pathogens responsible for certain diseases affecting the root system.

BIOSINERGY: suitable for use on medium-long cycle vegetables, this organic fertilizer activates the root system, containing humified organic matter, bacteria from the rhizosphere and inocules of mycorrhizal fungi. In addition to providing humified organic matter and nutrients, it promotes the formation of mycorrhizal symbiosis and the development of the root system. Its particular composition, rich in humic acids, stimulates the rooting and symbiosis between the root system and mycorrhizal fungi.

SUBLISAN FR: is a fluid organic fertilizer made with brown algae, able to preserve the spores of bacilli very useful for plants, such as Bacillus subtilis and  Bacillus amyloliquefa ciens. These bacilli, present at a concentration of 6×10¹⁰ uf.c./g, exert a natural biostimulating effect on plants and fruits, as well as strengthening their natural defenses. The organic nitrogen and organic potassium contained in Sublisan FR invigorate the plant, promoting enzymatic activities.