Italian Zeolitites in the Control of Grey Mould and Sour Rot and Their Effect on Leaf Reflectance, Grape and Wine

Abstract: The activity of two zeolitites, differing in the presence of copper and their particle size, was assessed in a Trebbiano d’Abruzzo white berry cultivar, towards grapevine grey mould and sour rot, a serious problem in almost all grapevine-growing areas. In 2018 and 2019, zeolitites were applied before forecast of rainfalls, which likely induce infection. In 2019, further applications were carried out 10 or 2 days before harvest, regardless of the rainfall, in order to verify the effect of the zeolitite residue on leaf reflectance and composition of grapes and wines. Both zeolitites significantly reduced the infections. Only the vines treated 2 days before harvest, especially with copper zeolitite, showed a decrease in leaf reflectance. However, no differences in the yield composition related to the time of zeolitite application, as well as a decrease of yield quality, were ever recorded. Furthermore, analysis of samples collected from vines treated with zeolitites showed increases in grape soluble solids and in wine alcohol content. Our results suggest the use of zeolitites against grapevine rots as a possible effective alternative to the application of synthetic fungicides in the development of environmentally friendly control strategies

Control of Grapevine Downy Mildew by an Italian Copper Chabasite-Rich Zeolitite

Abstract: The progressive reduction in the quantities of copper regulated by the European Union is focusing the research on new formulations with a reduced copper content but equally effective. In this regard, the activity of an Italian copper chabasite-rich zeolitite, which proved to be effective against grapevine grey mold and sour rot, was assessed against downy mildew. A two-year study was carried out in the Abruzzo region, Italy, in a cv. Montepulciano vineyard. The applications of the copper zeolitite showed the same good results obtained by a standard integrated/conventional strategy based on contact and systemic fungicides. At harvest, in both trial years, the plants with infected bunches in the untreated control ranged from 86.25% to 100%, compared to 15–30% of the treated plants. Furthermore, infected bunches and berries of the untreated control vines were 70–100% while treated ones never exceeded 2.32%. Furthermore, an increase in the polyphenol content and color intensity in wines made from vines treated with copper zeolitite was confirmed and appeared to be particularly evident in hot and dry seasons. The activity of copper zeolitite towards downy mildew, the potential use against grey mold and sour rot and the protection of grapes from high temperatures indicate that this product is a promising tool for a viticulture environmentally friendly control strategy

Nutritional status of vines affected with esca proper

A<span class="s3"> </span>vineyard of the cv. Trebbiano d’Abruzzo located in Abruzzo, Italy,<span class="Apple-converted-space">  </span>was monitored for more than ten years to distinguish healthy vines not only from vines with the visual leaf symptoms of esca, but also from those vines that were esca-infected but did not produce any visual symptoms for one or more growing seasons. In the period 2004–2006, leaves and berries were collected at four phenological growth stages from three groups of vines: healthy vines, infected vines showing esca symptoms, and infected vines that did not show symptoms. The macro and micro-elements of the leaves and berries, and the quality parameters of the must were determined. Esca did not seem to affect nutrient uptake in the vines. Nevertheless there were some differences in the nutrient levels of the leaves between healthy and diseased vines consistent with the degradation of the leaf blade caused by esca. Berries from symptomatic vines were less ripe at the time of harvesting and therefore had higher levels of mineral elements. These berries also had higher levels of nitrogen, which are thought to be associated with the defence response of diseased vines to esca, as are higher levels of iron in the leaves of diseased vines. The study confirmed earlier findings that fruit composition did not differ greatly between healthy and diseased-but-asymptomatic vines. In the three-year study period there were differences in the incidence of leaf symptoms and differences in nutrient levels attributable to fertiliser applications and rainfall. These differences suggested that the amount of mineral nutrients affected the onset of esca symptoms: a higher availability of nutrients in a growing season increased the proportion of diseased vines with symptoms and lowered the proportion of diseased vines without symptoms, whereas in a growing season with the lower levels of<span class="Apple-converted-space">  </span>water and potassium, the yield was reduced, but this was accompanied by an increase in the proportion of diseased vines without symptoms. It is suggested that a higher availability of nutrients for diseased vines lowers the resistance of these vines and, by improving the nutrition not only of the vines themselves but also of the esca fungi, increase fungal virulence, as a result of which there is a greater incidence of diseased vines showing leaf symptoms

Effect of Different Foliar Fertilizer Applications on Esca Disease of Grapevine: Symptom Expression and Nutrient Content in the Leaf and Composition of the Berry

Abstract: Esca disease, the most common grapevine wood disease in Europe, causes yield losses correlated with the foliar symptoms’ expression. In two vineyards located in the Abruzzo Region of Italy, each of which were investigated for esca symptoms after 1994, different applications of macro- and microelements were performed in two consecutive growing seasons. The main aim of the work consisted of verifying the effects of the fertilizer applications on the foliar symptoms’ expression, in order to deepen knowledge of the nature of the symptom, which is still unclear. For each treatment, in each year, the leaf content of macro- and microelements and the composition of berries and musts were assessed. The effects of these applications on vegetative growth and yield quantity were also verified. The trials were carried out on symptomatic, asymptomatic and apparently healthy vines. All applications, in particular those with microelements, increased the foliar symptoms’ expression, and a greater vegetative growth was detected only in vines treated with NPK fertilizers. The symptoms’ increase was always associated in the leaf with a decrease of calcium, and to a lesser extent, magnesium, reinforcing the hypothesis of the plant’s hypersensitive reaction in the development of foliar symptoms, given the role of calcium in the defense response. The vineyards were in nutritional balance regardless of the fertilizer applications. The general increase in foliar symptoms and the decrease in sugars in the musts of asymptomatic treated vines underlined the importance of the vegetative-productive balance, in Esca infected vineyards especially, in order to limit the symptoms’ expression and the decrease in yield

Italian Zeolitites in the Control of Grey Mould and Sour Rot and Their Effect on Leaf Reflectance, Grape and Wine

The activity of two zeolitites, differing in the presence of copper and their particle size, was assessed in a Trebbiano d’Abruzzo white berry cultivar, towards grapevine grey mould and sour rot, a serious problem in almost all grapevine-growing areas. In 2018 and 2019, zeolitites were applied before forecast of rainfalls, which likely induce infection. In 2019, further applications were carried out 10 or 2 days before harvest, regardless of the rainfall, in order to verify the effect of the zeolitite residue on leaf reflectance and composition of grapes and wines. Both zeolitites significantly reduced the infections. Only the vines treated 2 days before harvest, especially with copper zeolitite, showed a decrease in leaf reflectance. However, no differences in the yield composition related to the time of zeolitite application, as well as a decrease of yield quality, were ever recorded. Furthermore, analysis of samples collected from vines treated with zeolitites showed increases in grape soluble solids and in wine alcohol content. Our results suggest the use of zeolitites against grapevine rots as a possible effective alternative to the application of synthetic fungicides in the development of environmentally friendly control strategies.</jats:p

First Results of Management of Powdery Mildew in Grapevine Using Sulphur, Silicate and Equisetum arvense Formulations

The management of grapevine from diseases is now particularly focused on the development of environmentally friendly strategies. Although sulphur is not in itself a toxic substance, its extensive use in powdery mildew, in organic vineyards especially, may cause environmental problems and plant phytotoxicity and affect the health and safety of viticultural workers. The activity of sulphur applied at doses reduced up to 50% in tank mixtures with silicates or in Equisetum arvense-based products was assessed on powdery mildew in grapevine. Two-year trials were carried out applying the products every 7–10 days in the period of greatest risk for disease infections, in two organic vineyards in the Abruzzo region, Italy. In both vineyards throughout all trial years, at harvest, disease incidence and severity on leaves and bunches in the silicon + sulphur treatments were generally significantly lower compared to both the sulphur at full dose and to the control. In all trials, in both vineyards, a strong activity of silicon + sulphur mixtures towards disease on leaves was observed. This effect could be decisive in lowering the potential inoculum in the following season. In the Ari vineyard, vines treated with the mixtures always increased yield quantity and quality, given the higher contents of soluble solids and lower levels of total acidity. In the Cellino vineyard, probably due to the young age of the vines, increases in yield quantity were observed, with lesser effects on quality. The promising activity of the mixtures needs further studies to confirm these positive results. Furthermore, in both vineyards, the source of primary inoculum of the pathogen was observed as chasmothecia on the leaves

Application of Kaolin and Italian Natural Chabasite-Rich Zeolitite to Mitigate the Effect of Global Warming in Vitis vinifera L. cv. Sangiovese

High temperatures and the anomalous distribution of rainfall during the growing season may have a negative impact on grapevine yield and berry composition. In recent years, many studies have focused on the application of agronomical techniques to reduce the negative impact of heat waves on secondary metabolites such as phenols. In particular, treatments with kaolin have shown positive effects on reducing canopy temperatures, enhancing the accumulation of anthocyanins. In regard to the above, three treatments were evaluated: untreated control (C), kaolin (CAO), and chabasite-rich zeolitites (ZEO) applications on cv. Sangiovese in order to verify the cooling effects on leaves and bunches, and the impact on gas exchange, yield parameters, berry composition, and on both chemical and sensory notes of wine. Minerals were sprayed twice around the veraison on the entire canopy at a 3% concentration. The results showed that the application of the minerals was able to reduce the berry temperatures in both years of the trial as compared to the untreated control (C), without affecting vine gas exchange, yield, and soluble solid accumulation. Furthermore, the cooling effect determined an increase in anthocyanin on both the grapes and the wine. At testing, CAO and ZEO wines stood out regarding greater color intensity and were preferred by the judges.</jats:p