Any farmer dedicated to the production of vine and wine has had the plague phylloxera on his mind at some time in his life .
It has always been considered one of the pests with the highest incidence in vine cultivation and the one that has produced the most economic losses since its appearance many years ago.
This insect can be found in various phases of attack on the plant, although one of the most complicated is its “radicicultural” mode by which it attacks the roots of plants and sucks up all the cellular juice.
CHARACTERISTICS OF THE PHYLLOXERA OF THE VINE
Few pests currently exist with such a high incidence and rate of spread as phylloxera ( Daktulosphaira vitifoliae and also called Phylloxera vastratix ).
It was introduced in Europe at the end of the 19th century by ship from North America, and its expansion was international in a very short time.
The grape phylloxera is an insect pest that affects all type of vine varieties. It is considered a sucking hemiptera in full activity since the early 1800s.
In ancient times there was a lot of confusion because phylloxera can attack different parts of the plant, so each state was named in a different way.
For example, at the beginning of the plague in Europe, they named the form that attacks the root as R hizaphis vastatrix, and the galliform form ( Phylloxera vitifoli ).
Later it was decided to unify the classifications to the current one, such as Daktulosphaira vitifoliae or Phylloxera vastratix.
Read more: most important vine pests
YOUR ENTRY INTO SPAIN
The wine-growing relationship between Spain, Portugal and France allowed the rapid expansion of phylloxera throughout the cultivated territory.
The arrival of the plague in our country occurred in various ways and quickly.
Attempts to combat powdery mildew, one of the worst diseases of its time (and currently also) of the vine, led to different strains of more tolerant American varieties (such as “isabela”).
What they did not know is that they also brought the plague, and our European strains were extremely sensitive to this insect.
The first confirmed case of phylloxera in Spain occurred in the Málag area (1978), as a result of the importation of varieties that we have discussed.
When it comes to classifying it , phylloxera is the closest thing to an aphid, since its activity is based on the suction of cell juice from both the aerial part (mainly leaves) and the root, where it causes more damage.
THE RAPID SPREAD OF THE PLAGUE
The main problem of phylloxera on the vine is that the suction activity of this insect is slowly seen on the crop.
The attacks slowly weaken the plant , without knowing exactly what is the reason for the loss of vigor of our crop.
The vine acquires yellowish tones , lack of vigor, smaller and smaller fruits, etc., and we can attribute this problem to a lot of variables unrelated to the plague.
With the passage of time, if the sap extracted by the insects is greater than that manufactured, the plant collapses and dies . Depending on the presence of a greater or lesser volume of pest, it can happen in a short period of time.
The solution to the problem came from the very strains that caused the conflict. The American strains learned to live with the problem, and they were precisely the ones that were brought in, since they were tolerant to phylloxera attacks.
BIOLOGICAL CYCLE OF THE PEST
Phylloxera reproduction occurs in good weather conditions, especially in summer.
The laying is carried out on the trunk, with the well-known and denominated “winter eggs”. Take advantage of cracks in the bark and holes to protect them.
The hatching of these eggs occurs in the following year, in spring , forming aptera and parthenogenetic females that can remain in the leaves (chicken form) or in the subsoil (root form).
This female is capable of producing up to 3 molts during her juvenile phase (approximately in a period of 20 days). From here, it carries out the laying of up to 100 eggs that will form new parthenogenetic females.
The cycles are very fast, of 20 days, reason why the expansion of phylloxera takes place very quickly.
The most common form and the one that causes the greatest damage is the root phylloxera since the aerial forms do not usually reproduce or expand.
SYMPTOMS OF THE PRESENCE OF PHYLLOXERA
Phylloxera has a great ability to move between plantations, since the multiplication occurs due to its winged form .
The attacks carried out on the root, sucking the sap, create protrusions and deformations in said roots, reducing the flow of sap and obstructing the water and nutrient absorption channels.
In this way, the plant weakens quickly and collapses in a short time.
The aerial form (phylloxera gallicola) attacks the leaves, also creating protrusions that are very easy to detect on the beam.
In these galls, phylloxera spawns to increase its population volume in a short time.
The advance of the pest , under normal conditions, is usually not so fast.
The first season of phylloxera attacks are almost difficult to identify, since the crop is not overly weakened.
From the following season, when the vine is pruned and the shoots are removed, the plant cannot recover its energy and the plant collapses, with loss of production, chlorosis and absence of sprouting and development.
The most effective way to reduce the phylloxera problem was and is the grafting of European varieties on tolerant rootstocks .
In this way, although the problem is not eliminated, the majority of strains no longer die but simply their production is reduced.
To solve the problem definitively, it is necessary to resort to the winter and spring treatments with active ingredients that kill the phylloxera.
The main problem is that the phylloxera attack occurs in the subsoil, as it also occurs with the big-headed worm .
Therefore, treatments are needed that completely cover the rhizosphere and come into contact with the roots, either liquid treatments or in the form of gas (as carbon sulfide was used).
THE TYPE OF SOIL THAT CONDITIONS EVERYTHING
The phylloxera of the vine actively moves through the soil looking for new roots to suck up all the cell juice.
The greatest amount of sap movement in the root occurs during budding, since a lot of photoassimilates load is used for the construction of new roots .
In clay soils, phylloxera is able to create underground galleries very easily, since we are talking about a stable soil that conserves moisture very well.
However, in sandy soils , it is much more difficult to create galleries due to the phylloxera, so it often does not come into contact with the roots of the vine stock and the problem is limited.
SPRING AND WINTER TREATMENTS
There are some active ingredients that work very well against different soft-bodied insects, especially aphids.
- LAMBDA CIHALOTRIN 1,5% p/v
- ACETAMIPRID 20% SG