Chicory or radicchio ( Cichorium intybus ) is part of the Compositae family and is a species of European origin, so spontaneous varieties are very easily found in the meadows, which are those with blue-violet flowers.
The term chicory is mainly used to refer to chicory that is used as salads, and whose first part of the fleshy root (primary root) can also be eaten, while it is not used for Catalonia, which is called “catalog chicory”. “.
Chicories are botanically biennials, but are managed as annuals in cultivation because the vegetative part of them is harvested before going to seed. Normally chicory is taken from the head, in the case of chicory to cut the leaves. There are many varieties of chicory, the result of careful selection, which gave rise to the famous sour salads often referred to by their town of origin: for example, red chicory from Treviso, variegated chicory from Castelfranco or white chicory from Mantua. They are the classic winter salads, hardy and easy to grow, cold hardy and able to offer generous yields. They adapt perfectly to organic farming, so they are highly recommended both for small private gardens and for professional productions.
Spontaneous chicory flowers
But although radicchio is resistant to pests and diseases compared to other more delicate vegetables, sometimes it happens that it is also affected by certain adversities. Many diseases are favored by humidity, so the first rule of thumb is to avoid overhead irrigation, preferring a drip irrigation system. In a small garden, it is also very good to use the watering can, but wetting only the soil at the base and not the plumes. However, humidity is also linked to the season, since after the first summer period in which chicory transplants are carried out, cultivation continues in autumn-winter, when in many places in Italy the night humidity is high.
In particular, let’s see what diseases can affect chicory and what ecological remedies we can use to contain them. Some are real diseases because they are caused by pathogenic organisms such as fungi or bacteria, while others are non-parasitic in nature and are therefore called physiopathies.
Diseases of royal chicory
Diseases are real pathologies, in the case of chicory they are mainly caused by fungi or bacteria.
mushrooms like Pythium and the verticillium cause this disease, which occurs mainly in winter, both outdoors and in greenhouses. Symptoms begin with the outermost leaves of the lettuce wilting, rotting and dropping, then progressing to the neck, the tissues of which rot. When cutting the stem of the plant, you can notice the darkening of the internal vascular tissues, caused by the mycelium of the fungus.
The plumes thus affected, very obvious compared to the healthy ones, must be removed immediately to avoid contamination of other plants, and a product based on one or more antagonistic fungi of the genus Tricoderma must be distributed on the ground, capable of counteracting effectively the spread of tracheomycosis.
Pseudomonas cichorii Pseudomonas cichorii can damage chicory, especially near harvest. Bacterial rot in this salad is manifested by small dark brown internal spots, which are initially located at the edge of the leaf flap, and under conditions of high humidity they join together and give rise to extensive necrotic areas. The head rots by disintegration of the tissues and if the rot also affects the heart of the head, when the disease attacks in this way there is nothing left to recover.
Bacteria are retained in the soil and crop residues, so it is essential to rotate and compost all residues rather than letting them decompose in the garden.
Cercosporosis, a fungal disease, begins on the outer leaves of the head with isolated spots, which then enlarge but remain circumscribed by a reddish halo. The central tissues of the altered parts dry out and the flap remains perforated. It is a pathology typically favored by hot-humid weather.
The best prevention to limit the incidence is surely to transplant the chicory plants at adequate distances, carefully avoiding thickening them too much. Only in exceptionally severe cases is it best to treat them with copper-based Sigatoka products, always reading all the information on the label of the commercial product purchased.
The mushroom Puccinia cichorii it is responsible for rust, a pathology that appears towards the end of summer on the outer leaves of chicory, and is recognized by the classic rusty pustules that release spores, which further spread the disease among crops. After overwintering, in the spring, the fungus begins to attack spontaneous endives present in the environment, and from these it moves on to cultivated endives.
Again, rotations are the best form of prevention and ideally you should wait at least two years before repeating chicory cultivation in the same beds. In severe cases, treatment with copper products is possible.
Chicory Dietary Physiopathy
As expected, the pathophysiology is not really a disease, it is a state of suffering of the plant which manifests itself by symptoms suggesting a pathogen. In fact, if you understand the causes, you can intervene by providing the chicory plant with the right conditions to grow to their fullest and thereby remedy the situation.
This alteration causes a significant internal cavity in the lettuce root, and is caused by water imbalances, i.e. periods of plenty of water before periods of water scarcity. The outer tissues of the primary root grow rapidly, causing stretching of the tissue which leads to the appearance of this cavernousness.
In chicory, the hollow root is particularly damaging because not only the head but also the first part of the root is harvested for consumption, and if the plants are affected early by this anomaly, the plumes that form have a reduced vegetative development.
To avoid the appearance of hollow roots, the only strategy is prevention, which in this case translates into regular irrigation interventions in the first periods of summer growth, thus avoiding prolonged drought.
In fact, this is another pathophysiology, which mainly affects lettuce, but can also occur with chicory, when grown 5-6 times in a row in the same soil. The primary root does not develop properly, it remains reduced and of a corky consistency and, therefore, the plume cannot reach the potential size of the variety to which it belongs. Therefore, rotations are the best way to avoid this inconvenience.