With the rains the parasites return. But hatred for GMOs blocks possible solutions

After two dry spring seasons in our country 2023 was instead characterized by a significant amount of rainfall. Naturally, this could not fail to cause inconvenience to our agriculture: not so much, or not only, due to the excessive quantity of water in certain flooded areas, but above all because parasites that we had forgotten about in the previous two years, with the increased humidity rate are back in the limelight.

This is the case of the different parasites that cause the various types of downy mildew, and particularly the grape downy mildewwhich, introduced in the second half of the 19th century from America, causes both the appearance of the classic powdery “mold” on the underside of the leaves and, above all, serious damage to the bunches, especially when the berries are attacked by the so-called “larvated” form ”, without external manifestations, but with the complete destruction of the internal tissue.

Attilio Scienceprofessor of Viticulture and Oenology at the University of Milan, e Richard Cotarellapresident of Assoenologi, were clear: we risk serious damage to this year’s productionwith losses that could even reach over a third of the harvest in Puglia, Abruzzo and Basilicata, but with widespread damage also in Lazio, Umbria, Sicily, Veneto and Lombardy, particularly in the case of so-called organic vineyards, given that the treatments admitted by the disciplinary are much less effective than the conventional ones. “It is necessary to intervene with plant protection products”, declares prof. Science; and he is echoed by Cotarella, who in turn declared: “The diseases have not disappeared but above all there are still no viable alternatives to chemicals.”

And why, why are there no viable alternatives? Is it possible that research has failed to offer new means of containment, and that, faced with the failure of organic farming in times of parasitosis and plant diseases, one must necessarily resort to synthetic agents of various kinds?

Before answering this question, let me cite an example, just to demonstrate an important point: research has identified the solutions and how, and the problem does not lie in the scientific community. Less than a month ago, a work was published concerning an important cultivated plant, certainly not like the vine, but with its own specific niche in the food market: basil. A large group of Italian researchers, using CRISPR/Cas9they have edited the genome of this plant to obtain its resistance against downy mildew through the selective modification of a single gene. To do this, they inserted the appropriate “molecular tubes” into the plant through infection with an old acquaintance, the bacterium Agrobacterium tumefaciens, used for a long time and well before modern technologies to obtain genetically modified plants. Yield was high, because nearly 85 percent of the seedlings were modified, and the modifications were found to be transmissible to the offspring.

One specific strain among those obtained was found to be resistant to the infection of a classic downy mildew agent (the protist Peronospora belbahrii), thus demonstrating the success of the implemented genomic modification strategy; not all the transformed plants resulted equally resistant, due to the fact that the starting susceptibility of the seedlings used is probably different and (perhaps) also due to editing errors due to the method used.

Furthermore, the aromatic profile – i.e. the most important organoleptic characteristic of basil – was examined for all genetically modified seedlings, and was found to be independent of the experimental procedure implemented, and instead linked to the intrinsic variability of the seeds used by the researchers. In the future, they conclude, the progeny derived from these plants will have to be tested in field trials to evaluate their potential compared to current cultivarsto then create new lines of mildew-resistant sweet basil.

It is therefore demonstrated how the scientific community, and particularly the Italian one, when faced with a plant disease is perfectly capable of giving definitive answers which are not based on the massive and periodic use of chemical agents; but the demonization of plant biotechnology in Italy, with the cry of “no GMOs”, has made it impossible up to now to do what would have decreased environmental pollution, increased yields and made farmers’ work easier as regards multiple crops.

Now, behind the linguistic screen of the Teas, genetically modified plants can be tested in the field, but only until December 31, 2024, an impossible deadline for obtaining useful information in most cases where something to plant is not already available (and we hope that with basil we will succeed). It is no coincidence that with regard to downy mildew, Cotarella also stated: “We need to speed up the search for resistant varieties and work with genome editing to create new and more performing ones. But this takes time. It is not by setting a tight deadline that solutions will be found”. Already, it takes time to research: that time that up to now has been denied, and that more and more, with the worsening of the conditions of our planet, is becoming short, so that we can find those solutions that for so long have wanted to demonize.