1. Biological control of the insect
Today, already present in our experimental vineyards:
- CABERNET SAUVIGNON,
- VERMENTINO (ROLLE)
- TREBBIANO (UGNI BLANC)
Ecology was not the concern of our elders, almost always out of ignorance of what would happen in the next century. The chemical responses to Phylloxera were often very heavy (carbon sulphide, potassium sulfocarbonate, etc.), but especially economically unbearable by the entire “little people” winemaker.
Today, we do not imagine that we should be looking for a chemical response to the aphid, even if there are products, including hydrogen cyanide, not opposable to the ecological grafting techniques. Yet the chemical and carbon balance of grafting should be estimated, as it could reverse many prejudices and raise indignation.
It is not necessary to eradicate Phylloxera, but possibly to limit it, or to ensure that the vines of Vitis vinifera can coexist with it. A number of ways existed for a very long time, deserving to be rehabilitated as priorities, but new ones must be exploited.
Trapping techniques as they are practiced today especially against the worms of the cluster, which consist in counting the populations of the predators, to be able to treat them at the right time, are also tracks to be followed, on the winged stage of the Phylloxera reproductive cycle.
In the same way, repulsive techniques or the use of auxiliary predators deserve to be sought.
So the use of pathogenic fungi is a really interesting line of work. Methariziumhas been shown to be effective on several types of pests and aphids, but also against Phylloxera itself under laboratory conditions. It is especially necessary to obtain an administrative approval in order to be able to set up experimental field, though, lobbying contrary, it is undoubtedly the Homo politicus that we will first have to fight against or convince. The concerted action of the Association Les Vieilles Branches (AVB) and various stakeholders, could make this issue evolve favorably.
Beauvaria bassiana is already used effectively in biological control of various winged insects, such as mosquitoes, weevils and termites. A study conducted by the Research Institute - Development of Plant Protection in Bucharest (Romania) has already shown effective action on Phylloxera gallicole. This path deserves special attention, as do the sulphurous substances which have demonstrated their qualities in volcanic soils whose old free-standing vines are always free of Phylloxera.
Finally, how not to mention Amelia de Bompar who, in her booklet: «La vigne phylloxérée, sa guérison radicale par le fraisier» published in 1887, reported on her work and censuses in many vineyards, in France and Italy, showing that the strawberry-pineapple was a convincing remedy for Phylloxera. On the one hand because it is more palatable to the deadly aphid, but also because it harbors a mite (arachnid trombidium) which is a predator of aphids and their larvae. This path cannot be neglected by our contemporaries, simply because the patented researchers of the late nineteenth century viewed with a bad eye the encroachment of private initiatives on their self-imposed prorogatives. Let us at least learn this lesson from history.
The various biological insecticides available today, including natural cyanhydric acids (tobacco, bitter almonds, peach cores, cherry and cherry laurel leaves, cassava, sorghum etc.) even if they are toxic, could be evaluated with a specific objective.
Many plants, fungi or bacteria are used as insecticides, especially in agriculture. These products of natural origin are interesting in many respects (no residues, often selective action...), but they must be used with respect to the environment.
Pyrethrin is a natural insecticide extracted from the flower of a chrysanthemum, grown and harvested in Kenya. It is very effective in treating scale, aphids, caterpillars and many other warm-bolded animals, which allows it to be used in homes. It has the great advantage of deteriorating very quickly once it is applied, under the action of light.
Knowledge of Pyrethrin has led to the synthesis of neighbouring pyrethroids, which have the same characteristics of low toxicity to humans and low persistence, which are widely used as insecticides (e.g., permethrin). Its active ingredients are also used in medicine, for example in the treatment of lice.
There are many other natural insecticides, including:
• Rotenone, extracted from legume roots. • Nettle purées, consoude, ferns... which are well known to organic gardeners.
• Nettle purées, consoude, ferns... which are well known to organic gardeners.
Methods to support the plant’s immune defences (biodynamics, mycorrhizae, biostimulants, elicitors, etc.) must be studied.
Finally, we have basically planted flat and flood-prone plots in order to temporarily eliminate the insect by drowning, during the inevitable failures that will accompany our various experiments.
In the 21st century, man cannot scientifically abandon the field to a single insect, nor to the all-powerful chemistry, because of an imbalance that he himself caused, and whose consequences are immeasurable.