Atal Bianco

Class

Monocotyledons

Division

Angiospermae

Family

Amaryllidaceae

Order

Asparagales

Genus

Allium

Species

porrum

Description

A herbaceous plant cultivated for its leaves with a characteristic intense flavour and taste similar to onions but more delicate, appreciated in the culinary field to add a unique accent to typical Italian dishes, particularly during the autumn-winter period.

Relatively easy to grow, it requires exposure to full sun or afternoon sun in soil free of waterlogging as well as balanced fertilisation.

Variety description

Leek variety with a very early cycle. The length of the edible white part of the 'stem' is remarkable, easily reaching 30-40 cm, however, with successive pruning. The diametral calibre of the stem is among the highest compared to the varieties on the market. In temperate zones it is sown in late winter-spring for summer-autumn harvesting. The variety has a low cold hardiness. The leaves are a soft green colour, not very bright. Maturation is uniform. The flavour is pleasant, delicate and fine.

Curiosities and special features

Like other species belonging to the Allium genus, the leek contains the odourless amino acid alliin, which, when the leaves are cut, by the action of the enzyme alliinase is transformed into allicin, a molecule with antibacterial and antifungal properties and a characteristic intense odour.

Leek leaves also contain antioxidants such as vitamin C, vitamin A, carotenoids and polyphenols.

Origin and distribution

The leek is an ancient crop whose progenitor species, Allium ampeloprasum, is native to the eastern Mediterranean and the Middle East, later spread by the ancient Romans throughout much of Europe and the British Isles; today the numerous varieties are cultivated throughout Italy, especially in the centre-north.

Flower size

Flower individually is Medium in size.

Leaf

The intensely flavoured Leafs have shower-folded, embracing or amplexicaule laminae.

Fruit

The leaf is elongated and seedless, varying in size from 3 to 5 cm in width and diameter, while the length ranges from 20 to 30 cm; the weight ranges from 150 to 350 g and the texture is medium. The colouring is two-tone. The aroma is strong and penetrating, being intensely perfumed, while the flavour is characteristic, aromatic and intense, with a strong, decisive taste. The skin is not edible. The ripening period is from summer to autumn. The variety is characterised by good organoleptic characteristics, with marked sweetness and a rather vigorous plant with leaves that are always well stretched, resulting in an overall good quality.

Flowering period

Flowering occurs the year following the year of cultivation, from mid-spring to early summer.

Inflorescence

Inflorescence umbrella.

Leaf colour

Multicoloured, bicoloured shades.

Plant height

The height of the plant varies from 0.4 to 0.6 m.

Lifespan

Cultivated as an annual cycle plant.

Where to plant

In view of its bearing and planting density, it can be cultivated in beds, open field

Stem

The stem is herbaceous.

Flower

The flower has a simple, medium-sized shape and single-coloured petals. It is arranged in medium-sized umbel inflorescences. It flowers from mid-spring to late summer, with a flowering period of 20 to 30 days. It is attractive to bees and bumblebees.

Growth

The variety shows determined growth reaching a specific final size.

Plant habit

The bearing is typically erect.

PH

The ideal pH of Soil/medium ranges from slightly acidic to neutral, with values between 6.5 and 7.5.

Soil preparation

Before transplanting in spring, it is very important to prepare the soil correctly, by means of the following operational phases: spade the soil about 20/30 cm deep, eliminating any weeds and residues of previous crops, then fertilise the soil and, with the help of a hoe, break up the clods. In order to obtain correct drainage of excess water, thus avoiding harmful water stagnation, proceed by creating a raised flowerbed by ballasting the soil, then carefully level the surface using a rake, preparing the postarelle for transplanting.

During the cultivation cycle, remove the first 2/3 cm of soil by weeding or hoeing to remove any weeds present and break up any surface crust. In most cases it is advisable to carry out one or more ridging in the months preceding the harvest to encourage the stem whitening process.

Read more on the Joyflo blog

Sun exposure

Suitable for wind-sheltered , full sun exposure in the afternoon.

Ideal climate and temperature

The ideal temperature is between 15 and 25 °C.

Use

Variety cultivated and appreciated in

Agribusiness

Hardiness

Its rusticity is medium to high; it does not require any special cultivation care by ensuring regular and balanced fertilisation as well as taking care in the constant removal of adjacent weeds.

Soil

The ideal soil condition for leeks is medium-textured or sandy, structured, well-draining soil with organic matter.

Difficulty

Varieties whose cultivation is fairly easy with a medium level of management effort required.

Growing tips

Here are some tips and cultivation aspects aimed at obtaining the best production results:

Balanced fertilisation Avoid over-watering Require little but regular fertiliser

Intercropping/combination

Intercropping/combination with basil, cress, lettuce and radish is recommended.

Planting

In order to obtain an abundant final production, an average planting density of 18 plants per square metre is recommended in view of the size of the plant.

Transplanting should only be carried out when the seedling has 4/6 true leaves, ensuring that the root system is intact and not necrotized. Transplanting should also be carried out at the bottom of a furrow at least 10/15 cm deep to allow one or more ridges to be made later on, thus favouring the elongation of the edible part of the stem (whitening).

Read more on the Joyflo blog

Pruning

When harvesting, make a clean cut in the basal part of the plant to remove the root system; in addition, with reference to the leaf part, it is advisable to remove the outer leaves and cut off the terminal part of the fresh ones that have been left by means of a precise cut.

Propagation

Reproduction is by sowing in containers or in the open field; the leek is a biennial species if you intend to let it flower and then harvest the seed.

Watering

Use rainwater, or alternatively canal or aqueduct water with an optimal neutral pH, intervening manually or with a sprinkler system, using a perforated hose or through furrows, i.e. distributing the water in channels made between the rows. During the transplanting phase, assist the plant that may be more exposed to water stress in the new site, avoiding dry spells and maintaining a constant humidity without exceeding the quantities applied. Subsequently allow the soil or substrate to dry slightly between one watering and the next, also do not water the aerial part of the plant during the late afternoon/evening to prevent the spread of phytopathologies. In general, the water supply must be proportionate to the availability of water in the soil and the needs of the plant, particularly when sunshine and temperatures are high.

For eventual sowing, moisten the seed to allow it to germinate, after it has been completely buried and covered with a layer of substrate and inert material keep the soil wet until the sprout emerges.

Read more on the Joyflo blog

Fertilising

During pre-transplant soil preparation, carry out basic fertilisation by burying organic or chemical fertiliser. Then apply specific water-soluble fertiliser for horticultural crops to the Soil/medium, particularly with a higher nitrogen content in the growth phase, to be diluted in the irrigation water according to the dosages and frequencies indicated on the information label of the product purchased. Take care to meet the needs of the plant according to its stage of development by increasing the frequency of distribution during the period of intense vegetative growth.

Read more on the Joyflo blog

Edibility for humans

Leafs are edible.

Tip

It is essential to manage weeds correctly by eliminating them promptly through mechanical operations or the use of specific authorised herbicides. From the end of September to mid-November and from mid-March to mid-May there are ideal conditions for the development of the particularly harmful Liliaceae fly (Napomyza gymnostoma). In the summer period, on the other hand, it is the thrips that proliferate particularly on the young shoots, severely damaging the leaves. In all periods, downy mildew of the Liliaceae is dangerous. The three main pests must be adequately controlled when the minimum thresholds of presence are exceeded (downy mildew before symptoms appear). For a good harvest it is very important to fertilise with fertiliser with a high Phosphorus content in the post-transplant period, Nitrogen during the growth period and with a prevalence of Potassium during the pre-harvest period.