Composition for the treatment and / or prevention of grapevine esca disease

Abstract

The object of the present invention is a new composition, comprising a glycol having from 2 to 4 carbon atoms, an alkaline and / or alkaline earth metal acetate, and optionally an antioxidant, that can be used both for the treatment and / or prevention of grapevine esca disease, and as a fertilizer.

Description

The object of the present invention is a new composition that can be used both for the treatment and / or prevention of grapevine esca disease, and as a fertilizer. Background of the invention Esca disease is a grapevine disease caused by a group of fungi that colonize the lymphatic vessels and the wood, compromising the translocation of water and nutrients from the roots to the aerial part of the plant. Numerous experiments have not yet identified an effective fungicide against esca disease; currently, the preventive agronomic interventions to be carried out in the field in order to reduce possible sources of inoculum are the following: • marking diseased plants at the end of the summer season; • pruning marked plants separately; • removing dead or severely damaged plants and old wood residues; • reducing the use of large pruning cuts; • disinfecting wounds and covering them with mastics. The technical problem addressed and solved by the present invention is the development of a new composition that can be used not only for the treatment and / or prevention of grapevine esca disease, but also as a fertilizer. Definitions Unless otherwise defined, all terms of the art, notations and other scientific terminology used herein are intended to have the meanings commonly understood by those skilled in the art to which this disclosure pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and / or ready reference; thus, the inclusion of such definitions in the present disclosure should not be construed to represent a substantial difference over what is generally understood in the art. Unless otherwise indicated, percentages are to be intended as by weight, based on the total weight of the claimed composition. The terms “comprising”, “having”, “including” and “containing” are to be intended as open-ended terms ( / .e., meaning “comprising, but not limited to”), and are to be considered as a support also for terms such as “consist essentially of”, “consisting essentially of”, “consist of”, or “consisting of”. The terms “consist essentially of”, “consisting essentially of” are to be intended as semi-closed terms, meaning that no other ingredients affecting the novel features of the invention are included (optional excipients may therefore be included). The terms “consists of”, “consisting of” are to be intended as closed terms; i.e., the sum of all the components represents 100% of the total. Figures Figure 1 shows the incidence and severity of esca disease in grapevines treated with the composition of the present invention, and in untreated grapevines. Figure 2 shows net photosynthesis (Pn) and carboxylation efficiency (iACE), parameters in grapevines treated with the composition of the present invention, and in untreated grapevines. Figure 3 shows transpiration (E) and stomatai conductance (gs) parameters in grapevines treated with the composition of the present invention and in untreated grapevines. Description of the invention It has now been surprisingly found that a chemical compound normally used as an antifreeze additive, i.e. a glycol having from 2 to 4 carbon atoms, can be effectively used as a fungicide, and has a particular efficacy in the treatment and / or prevention of grapevine esca disease; it has also been surprisingly found that said glycol also has fertilizing activity. An aspect of the present invention is therefore represented by the use of a glycol having from 2 to 4 carbon atoms in the aforementioned applications. A further aspect of the present invention is further represented by a specific composition based on said glycol, usable for the aforementioned applications. According to an aspect of the present invention, the glycol having from 2 to 4 carbon atoms is selected from propylene glycol and / or ethylene glycol, preferably propylene glycol. An aspect of the invention is further represented by a composition comprising from 71% to 81% of at least one glycol having from 1 to 4 carbon atoms, from 19% to 29% of at least one alkali and / or alkaline earth metal acetate, and optionally at least one antioxidant. According to an aspect of the invention, the composition comprises from 73% to 79% of said glycol, preferably from 74.5% to 77.5%, more preferably 75.9%. According to an aspect of the invention, the composition comprises from 21% to 27% of at least one alkali and / or alkaline earth metal acetate, preferably from 22.5% to 25.5%, preferably 24%. According to an aspect of the invention, the alkali and / or alkaline earth metal acetate is selected from potassium acetate and / or sodium acetate, preferably potassium acetate. According to an aspect of the invention, the composition may comprise at least one antioxidant; the preferred antioxidants are selected from phenolic antioxidants, such as for example vitamin E (a-tocopherol) or caffeic acid; carotenoids and vitamin A (ascorbic acid). Vitamin E is the preferred antioxidant. According to an aspect of the invention, the composition may comprise from 0.01% to 1% of said antioxidant, preferably from 0.05% to 0.5%, more preferably from 0.075% to 0.25%, even more preferably 0.1%. According to an aspect of the invention, said at least one glycol having from 1 to 4 carbon atoms, preferably propylene glycol, said at least one alkali and / or alkaline earth metal acetate, preferably potassium acetate, and said at least one antioxidant, preferably vitamin E, constitute 100% of the composition. According to a preferred aspect of the invention, the composition is comprised of 75.9% by weight of propylene glycol, 24% by weight of potassium acetate, and 0.1% by weight of vitamin E. According to an aspect of the invention, the above composition can be applied to grapevine in combination with at least one plant protection product, in particular in combination with a plant protection product against downy mildew and / or powdery mildew, such as sodium and potassium phosphonates, algae extracts, plant extracts, foliar fertilizers, kaolin, sulfur, copper, Oxathiapiprolin, Amisulbron, Dimetomorph, Folpet, Metalaxil-M, Zoxamide, Cimoxanil, Mandipropamid, Meptyldinocap, Azoxystrobin, Spiroxamine, Metiram, Zoxamide, Cyflufenamid and / or Proquinazid. According to a further aspect of the invention, the above composition can be applied to grapevine simultaneously, separately or sequentially with respect to the above at least one plant protection product. These and further aspects of the invention will be apparent from the following experimental section, which has an illustrative and non-limiting purpose only. Experimental section Protocol The following composition was used in an experimental protocol for the treatment of grapevine esca disease in three consecutive crop years (2021, 2022, 2023) in three different areas and with two varieties. Product AF5-E • 75.9% propylene glycol • 24% potassium acetate • 0.1% vitamin E (Irganox E 201) The dose used was 0.5 liters per hectare, for a total of 17 treatments starting 15-20 days after bud break, 12-15 days apart. In order to evaluate the effect of the product, fields already monitored for the presence of esca disease and with a uniform distribution of the disease were selected. Each field was divided into two plots of equal size (0.5 hectares) and monitored for the incidence and severity of the disease during the course of the season. Scoring of disease indices, i.e. incidence and severity, was carried out using the University of Adelaide’s Grape Assess mobile app; see for example Waters , Wine Australia: Have the wood on grapevine trunk diseases, W / ne & Viticulture Journal 34:10 (2019) or Giudice et al., Novel sustainable strategies to control Plasmopara viticola in grapevine unveil new insights on priming responses and arthropods ecology, Pest Management Science, Wiley Online Library (2022). Incidence represents the ratio of symptomatic observations to the total number of plants observed, while severity represents the symptomatic area of each plant as a percentage. For each company, the experiment was carried out on 1 hectare of extension divided in half, of which one half treated with the product AF5-E, incorporated in the usual plant protection products commonly used for the treatment of downy mildew and powdery mildew, and one half in which the product AF5-E was not used. The second half, not treated with AF5-E, was used for comparative purposes to observe the incidence of the disease without the application of the product. The test was repeated on different plots in the localities of Lonigo (Glera variety), Cozzuolo (Glera variety) and Fossalta di Portogruaro (Cabernet Sauvignon variety). The number of treatments indicated depends on the variable weatherclimate conditions of each year. This is because the AF5-E product is miscible with the usual plant protection treatments applied in wine-growing companies against downy mildew and powdery mildew, such as sodium and potassium phosphonates, algae extracts, plant extracts, foliar fertilizers, kaolin, sulfur, copper, Oxathiapiprolin, Amisulbron, Dimetomorph, Folpet, Metalaxil-M, Zoxamide, Cimoxanil, Mandipropamid, Meptyldinocap, Azoxystrobin, Spiroxamine, Metiram, Zoxamide, Cyflufenamid, Proquinazid. For this reason, the AF5-E product has been integrated into the composition of the usual treatments normally used by the wine-growing companies being tested. This practice appears to facilitate the application of the product since, by not having to carry out ad-hoc steps in the field for distributing the product, it results in savings for the companies. Furthermore, the AF5-E product has demonstrated a tackifier action that allows for better persistence of the other products that are applied at the same time. Disease indices In 2023, the months of May, June and July were characterized in northern Italy by high rainfall, which followed a dry winter period, causing an early onset of symptoms and a higher incidence than in previous years. In the month of August, average temperatures and sporadic rainfall were recorded which further favored the onset of esca disease symptoms. The results, reported in Figure 1, demonstrate that the application of the AF5-E product has a significant effect in reducing the incidence of symptoms and the incidence of esca disease compared to samples treated with plant protection products alone. In the Cozzuolo (Treviso) field, where the product was applied on the Glera variety suitable for Prosecco, esca disease had an incidence of 24.3% with a severity of 20.5% on the untreated half, while it had an incidence of 9.7% and a severity of 8.3% on the half treated with the AF5-E product, with a statistically significant difference for both disease indices. In Fossalta di Portogruaro (Venice), with application on the Cabernet Sauvignon variety, esca disease showed an incidence of 18.7% with a severity of 19.7% on the untreated half and 8.7% and 9.7%, respectively, on the half treated with the AF5-E product; indices show statistically significant differences also in this case. In Lonigo (Vicenza), where the product was applied on the Glera variety, the disease showed an incidence of 17.8% with a severity of 19.4% on the untreated half and 6.3% and 7.7%, respectively, on the half treated with the AF5-E product; both indices show statistically significant differences also in this case. Eco-physiological measures: leaf gas exchange analysis The results obtained on the AF5-E product effectiveness in containing the symptoms, and therefore avoiding apoplexy and loss of production, led to the decision to deepen the analysis and understand the mechanism of action of the product at multiple levels: eco-physiological of the plant, molecular and biochemical. At the eco-physiological level, IRGA (infrared photodiode leaf gas exchange analyzer), a tool that allows to measure the physiological performance of the plant measured in real time and is non-destructive, was used. In full vegetative season, end of August 2023, leaf gas exchanges were measured in at least 10 plants per treatment (2 leaves per plant, randomly selected in the middle of the leafage) and measuring leaves that did not show any obvious symptoms of esca: - untreated control plants with obvious symptoms of esca (Syn CTRL); - untreated asymptomatic control plants (As CTRL); - plants treated with AF5-E with obvious symptoms of esca (Syn AF5-E); - asymptomatic plants treated with AF5-E (As AF5-E). As reported in Figure 2, at the level of net photosynthesis (Pn) and carboxylation efficiency (iACE), a parameter related to photosynthetic efficiency), no significant differences are apparent within the treatments. As expected, the photosynthetic rate is slightly lower in plants that show symptoms, even if symptomatic plants treated with AF5-E show higher rates than Syn CTRL. Since non-symptomatic leaves were measured in each treatment, it is clear that the product has no effects on net photosynthesis, not compromising in any way the productive performance of the plant at a physiological level (in the figures, the asterisks indicate significant differences compared to Syn CTRL). As reported in Figure 3, transpiration (E), i.e. the water released by leaves into the atmosphere, results to be (even significantly) higher in grapevines treated with AF5-E. Very interestingly, Syn AF5-E have a very high E rate. Similar results were also observed in stomatai conductance (gs), a parameter that indicates the stomata opening degree for the release of water into the atmosphere and for the absorption of CO2 useful for the photosynthesis process. As can be observed, Syn CTRL show significantly lower levels of both E and gs than all other treatments. The Syn AF5-E treatment, instead, is significantly higher than Syn CTRL in both parameters; this is a very interesting aspect that allows us to hypothesize a so-called growth-defense trade-off phenomenon. That is, plants treated with AF5-E show much lower severity and incidence indices than CTRL, therefore the slight reduction in photosynthesis and the higher transpiration and stomatai conductance rates suggest that part of the energy resources are used for the defense and containment of esca pathogens. AF5-E probably triggers the activation of the plant’s endogenous defense systems useful for containing the symptoms, but to affirm this with certainty we will evaluate the grapevine defense pathways in the collected leaf samples at the molecular and biochemical level and will make various comparisons. Asymptomatic plants are similar, proving that AF5-E does not affect water metabolism and stomata regulation, essential aspects for plant physiology and, therefore, production. In summary, the application of the product does not disturb the physiological state of the plant and can therefore be applied without risks to the photosynthetic apparatus. In the presence of the typical esca symptoms, plants treated with AF5-E show an increase in the transpiration rate, which is synonymous with the use of the plant’s metabolic energy to contain its development, and therefore the symptoms, without significantly affecting photosynthetic efficiency. The data reported above therefore confirm that the composition object of the present invention, and more generally glycols having from 2 to 4 carbon atoms, can be used both for the treatment and / or prevention of esca disease, and as a fertilizing agent, in particular for grapevines. Qualitative analysis of grapes at harvest At harvest, bunches were sampled from at least 5 plants randomly selected in each condition. The must was obtained from the fresh samples, on which the following analyses were performed: sugars, total acidity and pH; the results are reported in the following table. Syis CTRL Sugai's (%) I5.li0.00a Total Acidity (%)' 7.5x0.09c pH 3.11x9.00b Yield per plant (Kg) 2...5i0.30a As CTRL 16.9±0.00c 6.5±0_00a s.isio.oic 5.2±0.50c Syn AF5-E 15.9±0.00b 7.5±0_00c 3.06i0.01a 3.5±9.40b As AF5-E 16 9x0 90r 7Tx0.00b S Hx{}{}:C 5.3i0.60c (DsfSereai letters m the cohmssi indicate that there are statistically significant differences between the cssiditioiis. Tukey HSD Test p < 0.05) Similarly to what was observed in the ecophysiological analysis, asymptomatic plants (As) CTRL and AF5-E behave the same, except for the total acidity which is slightly higher in the plants treated with AF5-E, suggesting a slight delay in technological maturation, a characteristic that can be appreciated in the light of climate change. In fact, following the increase in temperatures, the harvest time is increasingly anticipated. The increase in acidity is therefore a factor of extreme interest for winemakers. Confirming what was seen previously, the application of the AF5-E product does not disturb maturation and qualitative characteristics of the grapes during the harvest phase. In general, symptomatic plants (Syn) have, as expected, less sugars and a higher total acidity despite sugars being significantly higher in the plants treated with AF5-E, where the impact of the disease is reduced, as well as the yield, when compared to Syn CTRL. In fact, this confirms what was observed with the disease indices and demonstrates the effectiveness of the tested product in reducing the impact of esca syndrome on the yields and quality of the grapes produced.

Claims

1. Composition comprising from 71% to 81% by weight of at least one glycol having from 2 to 4 carbon atoms, from 19% to 29% by weight of at least one alkali metal and / or alkaline earth metal acetate, and optionally at least one antioxidant.

2. Composition according to claim 1, characterized in that it comprises from 73% to 79% by weight of said glycol, preferably from 74.5% to 77.5%, more preferably 75.9%.

3. Composition according to any one of the preceding claims, characterized in that said glycol is propylene glycol and / or ethylene glycol.

4. Composition according to any one of the preceding claims, characterized in that said glycol is propylene glycol.

5. Composition according to any one of the preceding claims, characterized in that it comprises from 21% to 27% by weight of said acetate, preferably from 22.5% to 25.5%, more preferably 24%.

6. Composition according to any one of the preceding claims, characterized in that said acetate is potassium acetate and / or sodium acetate.

7. Composition according to any one of the preceding claims, characterized in that said acetate is potassium acetate.

8. Composition according to any one of the preceding claims, characterized in that it comprises an antioxidant.

9. Composition according to any one of the preceding claims, characterized in that said antioxidant is selected from phenolic antioxidants, such as for example vitamin E (a-tocopherol) or caffeic acid, carotenoids, and vitamin A (ascorbic acid).

10. Composition according to any one of the preceding claims, characterized in that said antioxidant is vitamin E.

11. Composition according to any one of the preceding claims, characterized in that it comprises from 0.01% to 1% by weight of said antioxidant, preferably from 0.05% to 0.5%, more preferably from 0.075% to 0.25%, even more preferably 0.1%.

12. Composition according to any one of the preceding claims, consisting of 75.9% by weight of propylene glycol, 24% by weight of potassium acetate and 0.1% by weight of vitamin E.

13. Use of the composition according to any one of the preceding claims, as a fungicide.

14. Use of the composition according to any one of the preceding claims, for the treatment and / or prevention of grapevine esca disease.

15. Use according to claim 14, characterized in that said composition is applied to grapevine in combination with at least one plant protection product.

16. Use according to claim 15, characterized in that said plant protection product is against downy mildew and / or powdery mildew.

17. Use according to claim 15 or 16, characterized in that said at least one plant protection product is selected from sodium and potassium phosphonates, algae extracts, plant extracts, foliar fertilizers, kaolin, sulfur, copper, Oxathiapiprolin, Amisulbron, Dimetomorph, Folpet, Metalaxil-M, Zoxamide, Cimoxanil, Mandipropamid, Meptyldinocap, Azoxystrobin, Spiroxamine, Metiram, Zoxamide, Cyflufenamid, Proquinazid.

18. Use according to any one of claims 15, 16 and 17, characterized in that said composition is applied to grapevine simultaneously, separately or sequentially with respect to said at least one plant protection product.

19. Use of the composition according to any one of the preceding claims, as a fertilizer.

20. Use of a glycol having from 2 to 4 carbon atoms as a fungicide, in particular for the treatment and / or prevention of grapevine esca disease.

21. Use of a glycol having from 2 to 4 carbon atoms as a fertilizer.

22. Use according to any one of claims 20 and 21, characterized in that said glycol is propylene glycol and / or ethylene glycol, preferably propylene glycol.

Images