Searches

The sadness of citrus fruits


Sadness of citrus fruits: all information on the disease caused by the Citrus Tristeza Virus. Course, symptoms, remedies and prevention.

Theresadza of citrusit is a serious disease caused by the virusCitrus Tristeza Virus. There are no remedies for this disease, so we must play prevention. When a citrus is attacked by thesadnessit can only be eradicated: there are no natural remedies on the market, nor effective phytosanitary products to eradicate this disease.

Theresadness, better known asCitrus Tristeza Virusor CTV, is the most widespread and severe disease of citrus fruits. Therecauseof this citrus disease is the virus of the genusClosteroviruswhich leads the affected plants to rapid decline and death.

Symptoms of citrus tristeza

The first obvious symptom is thedecaybecause the virus attacks thephloem, that is, the tissue that carries the processed sap from the leaves (with photosynthesis) to the roots. With the death of the phloem, in times of stress caused by excessive heat or drought, the plants affected by the virus cannot sustain themselves and begin to wither. Some strains of the virus manage to cause the death of the plant within 1-2 weeks of the appearance of the first symptoms.

It is not possible to cure the symptoms. If the plant was fruiting, not only will the fruits appear deformed but will cease to grow or ripen, sticking to the dead plant. Other symptoms of thesadza of citruswe point out the pitting of the wood.

How to tell if the plant is attacked by the tristeza virus?

A) Lift a piece of bark in correspondence with the graft line. If there is a sort of punctiform alveolation on the cambial face of the rootstock bark, the virus is present. This alveolation manifests itself with many holes or rubber deposits. This is not an absolute diagnostic criterion because in many cases it is not present as well as the pitting, that is the grooves that can be observed on the trunk and branches, under the bark.

B) Apply a few drops of iodine tincture on the wood, at the graft point. If the dye turns purple, the virus is present. The color variation is dictated by the excessive accumulation of starch at the graft point.

Tristeza of citrus, remedies and prevention

When the first appearsymptomsof thesadza of citrusit is too late and nothing will be able to tear the plant from death. The only remedy is prevention.

How is citrus sadness transmitted?Transmission is vegetative (i.e. through grafting material) or through vectors, i.e. through insects that carry the virus from one plant to the other.

The carriers of theCitrus Tristeza Virusare several species of aphids, the most dangerous is theToxoptera citricidus, insect better known as brown citrus aphid. Fortunately this insect has not yet colonized the Italian citrus groves even if it has been present in Spain since 2005, so in the very near future it could arrive in our crops. In our country, the most dangerous vector aphid is the Aphis gossypii or cucurbit aphid.

Prevention is based on avoiding the risk of virus transmission, therefore:

  • For citrus fruit grafts, use only safe propagation material.
  • In the case of infected plants, remove the tree immediately! Avoid recovery attempts such as re-grafting or crown reduction with pruning.
  • Use virus resistant rootstocks such as trifoliate orange hybrids.
  • Follow the preventive prophylaxis used against the cucurbit aphid.

Keep in mind that bitter orange is a very good rootstock in our soil and climatic conditions, however it is very sensitive to the virus. Trifoliate Orange is the most suitable for grafting sweet orange, it is rustic and resists the cold well. It shows early, abundant and good quality fruiting. It cannot tolerate calcareous and brackish soils.



Video: benefits of citrus fruits for breakfast (December 2021).