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Use of Potassium Silicate for the Control of Powdery Mildew [ Uncinula necator (Schwein) Burrill] in Vitis vinifera L. Cultivar Bacchus
Abstract and Figures
Bacchus (Vitis vinifera L.) vines trained to a vertical canopy were subjected in the 1991 to 1993 growing seasons to one of three spray materials for the control of powdery mildew: distilled water (control); Kumulus S (micronized sulfur; commercial control); and potassium silicate (K2SiO3). In 1991 infection on berries and shoots of K2SiO3-treated vines was equal to that on Kumulus S vines at veraison and mid-Stage III, but exceeded Kumulus S by harvest in 1991. In 1992 and 1993, both spray materials exceeded the control treatment in terms of mildew control, based upon harvest infection ratings; K2SiO3 equalled Kumulus S in 1992 but failed to provide the same level of control under heavy disease pressure in 1993. Triangle tests on 1991 and 1992 wines showed no aroma or flavor differences between Kumulus S and K2SiO3 treatments but tasters could distinguish between control wines and the other two treatments in the 1991 wines (tank samples and aged wines), and between 1992 control and Kumulus S wines. Yields were lowest in control plots in all three seasons, and control vines also produced lowest cluster weights and berry weights in 1993. No noteworthy differences were observed between treatments in terms of composition of berries, juices, or wines. Scanning electron microscopy and energy-dispersive X-ray analysis of the control and Kumulus S-treated berries showed large quantities of Si deposited near infection sites and hyphae, suggesting that grape berries may utilize endogenous Si to help fight disease. This suggests that exogenously applied silicates may act to augment the activity of their endogenous counterparts. At appropriate application intervals and concentration, K2SiO3 has potential as an alternative spray material to sulfur for powdery mildew control because: (1) material cost is lower; (2) risk of H2S in wines is reduced; and (3) it would potentially fall within guidelines for 'organic' winegrowers as a natural substance.
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... Applications of potassium silicate (K 2 SiO 3 ) on cucumber, muskmelon, zucchini squash, strawberry, wheat, and grape reduced the severity of powdery mildew, and only in a few cases had effects on plant growth and yield [24][25][26][27]. However, in some cases, potassium silicate applications on grapevines failed to provide adequate control under high disease pressure [28]. In numerous crops, foliar applications of silicic acid increased growth, yield, and quality parameters [29-31]. ...
... Therefore, positive results have been obtained with silicates and silicic acid in the disease control, vegetative growth, and plant yield of numerous crops. However, these compounds have not been much investigated on grapevine, and among the few investigated compounds, potassium silicate has not shown fully satisfactory results in the control of powdery mildew or improvement in grape yield [26,28]. The present study was carried out in organic vineyards at high risk for powdery mildew where a high amount of sulphur is frequently applied. ...
... It might be that the damage of fungal cells, the impairment of respiratory processes, the protein denaturation, and the formation of toxic compounds induced by sulphur can be further improved by the reinforcement of the cell wall and the induction of plant resistance through the action of silicon-based products [34,53,54]. The combination of the different mechanisms of action could therefore be the reason for the higher effectiveness of these mixtures in the control of powdery mildew, compared to what was found in studies carried out on vines with potassium silicate, which did not show satisfactory effects in the presence of high disease pressure [26,28]. However, the effectiveness of silicates and E. arvense is in line with the results obtained on different crops with foliar applications of other silicates or silicic acid [23]. ...
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.
... Anecdotal evidence suggests that the application of atmospheric silica (501) sprays may "strengthen" the plant through the thickening of cell walls and enhanced light assimilation of the plant, leading to better fruit and seed development with improved flavour, aroma, colour, and nutritional quality. Foliar sprays containing silicon have demonstrated the ability to enhance plant responses, including improved quality, yield, and resistance to pests and diseases (Bowen et al., 1992;Reynolds et al., 1996;Soylemezoglu et al., 2009;Laane, 2017). Silica application has been linked with increased cell wall and membrane thickness in leaves and in turn an increase in grapevine disease resistance (Rashad et al., 2021). ...
Consumer awareness of environmental sustainability and concern for food safety and quality is driving increased demand for organic and biodynamic (BD) produce. This is coupled with a more physically and economically challenging environment pushing producers to explore more sustainable management techniques. Biodynamic viticulture has both environmental and marketing benefits as drivers and involves the application of a series of nine preparations to soil and plants. Biodynamic preparation 501 is silica-based and has minimum yearly use requirements for certified growers. There are conflicting reports of silicon-based foliar sprays eliciting favourable plant reactions about improvements in quality, yield, and resistance against pests and diseases. Here, vine growth, yield components, berry and wine composition analyses, and sensory evaluations were conducted in two seasons to compare the effects of biodynamic and commercial silica treatments against a water control on Semillon and Cabernet-Sauvignon (Vitis vinifera L.) vines. In both seasons differences in yield and vine growth were observed. Generally, yield was greater with the application of biodynamic silica and potassium silicate. Basic berry compositional attributes pH, TA, TSS, and total anthocyanins and phenolics showed little to no differences. Sensory descriptive analysis of berries and wine indicated significant differences in attributes related to skin and seed tannins, implying that these analyses may better detect subtle yet important variations in the vineyard. The results of this study suggest a direct correlation between silicon and polyphenols, potentially influencing sensory mouthfeel characteristics through changes in skin thickness and/or structure. This study indicates that applying silica can positively impact vine performance and quality.
... Qin et al. (2016) found that Si can protect photosynthetic machinery from damage, enhancing the efficiency of photochemical reactions in photosystem II, and improve the salt tolerance of the grape by increasing the concentration of soluble sugars and starch. Several studies Lafos 1995;Reynolds et al. 1996) have demonstrated reduced powdery mildew incidence when Si is applied in greenhouse conditions, despite no significant varietal differences were found. Notably, Blaich and Grundhöfer (1997) observed substantial varietal variations in interspecific hybrid grape cultivars, with cv. ...
Silicon (Si) has emerged as a pivotal element influencing various aspects of plant growth and development. This review explores the multifaceted effects of Si on plants, encompassing both biotic and abiotic dimensions. Si, primarily absorbed by plants in the form of orthosilicic acid, demonstrates a diverse range of roles in enhancing plant resistance to environmental stresses. Biotic stresses, including pathogen attacks and insect infestations, are notably mitigated by the deposition of Si in plant tissues, fortifying cell walls and triggering defence mechanisms. Furthermore, Si plays a crucial role in alleviating abiotic stresses such as drought, salinity and metal toxicity, imparting resilience to plants in challenging environments. The interaction between Si and plant physiology involves intricate mechanisms, impacting nutrient uptake, photosynthesis and hormonal regulation. As research in this field advances, a comprehensive understanding of the nuanced effects of Si on plants emerges, paving the way for innovative agricultural practices and the development of stress-resistant crop varieties. This review delves into the contemporary knowledge surrounding the effects of Si on plants, underscoring its significance in promoting plant resilience and sustainable agriculture.
... Equisetum arvense decoction contains also various inactive compounds, together with the potential active components, like organic silicic acids. Several studies have also shown that silicic acids own antifungal activity (Reynolds et al., 1996;Fauteux, 2006). Horsetail decoction has long been used as a fungicidal extract. ...
Equisetum arvense is an herbaceous perennial plant traditionally used in human medicine (i.e. for organic silicon supplementation). It is an approved basic substance with fungicidal properties under Article 23 of agricultural EU pesticide regulation (EC) No 1107/2009 (Anonymous, 2009) since 2014 and in Organic Production since 2016. Currently, its approved uses are for arboriculture, horticulture, ornamentals and viticulture through initial approval and two use extensions granted in 2016 and 2017. Further use extensions to allow cereal use have been submitted to the EU Commission for evaluation in 2018.
Thus, fungicide usages for the cereals are being evaluated by the EU regulatory assessment organisation, with ESA outcome in 2020 and further discussion at Commission level since. Horsetail extract has recently been shown to have antibacterial, antifungal, antioxidant, analgesic, anti-inflammatory, antidiabetic, antitumor, cytotoxic and anticonvulsant activities. Initial main field trials to demonstrate its plant protection properties were coordinated in France by the “4P” project “Protection des Plantes Par les Plantes” (Plant Protection by Plants) between 2010 and 2013 but additional field trials were later collected.
We detail in this study the results obtained and all the uses of this decoction as a plant protection product. In addition, we describe the full approval processes for the basic substance Equisetum arvense and the extensions of use, covered by the Article 23 of the plant protection regulation in EU.
... Selection for cultivars with thicker cuticles appears to contribute some degree of resistance against infections from B. cinerea and seems to enhance resistance against sour rot Gabler et al. 2003). Moreover, it has been reported that grapevines sprayed with silicon had less severe powdery mildew (Bowen et al. 1992;Reynolds et al. 1996) but there is no report of silicon increasing plant resistance to grape rots. ...
Cluster rots can be devastating to grape production around the world. There are several late-season rots that can affect grapes including botrytis bunch rot, sour rot, black rot, phomopsis fruit rot, bitter rot and ripe rot. Tight-clustered varieties such as 'Pinot gris', 'Pinot noir', and 'Vignoles' are particularly susceptible to these cluster rots. Symptoms or signs for these rots range from discolored berries or gray-brown sporulation in botrytis bunch rot, to sour rot, which smells distinctly of vinegar due to the presence of acetic acid bacteria. This review discusses the common symptoms and disease cycles of these different cluster rots. It also includes useful updates on disease diagnostics and management practices including practical aspects of cultural practices and host resistance in commercial vineyards and future prospects for disease management. By understanding what drives the development of different cluster rots, researchers will be able to identify new avenues for research to control these critical pathogens.
... Previous studies showed that the supplement of silicon to grapevine can increase the efficiency of the photochemical reactions in photosystem II (Qin et al. 2016), whereas Liang et al. (2015) state that silicon might play an important role in protecting the photosynthetic machinery and improve salt tolerance. The studies of Bowen et al. (1992), Reynolds et al. (1996), and Lafos (1995) showed reductions of powdery mildew in response to silicon application in greenhouses but emphasised large differences between cultivars. Blaich and Grundhöfer (1997) showed significant varietal differences only for the inter-specific hybrid grape cv. ...
Replacing Bordeaux broth and synthetic fungicides by less invasive approaches of fungal disease control remains a challenge for both conventional and organic viticulture. Silicon (Si) application has been proposed as a viable alternative for the control of pathogens and other stresses in agriculture. In a three-year field trial, we tested the effect of foliar and soil application of colloidal silicon on its availability in vineyard soil and pants, the performance and quality of yield, and finally, the control of powdery mildew for grapevine cv. Grüner Veltliner. Soil application of colloidal silicon increased plant-available Si, but only foliar application increased the total silicon concentrations in leaves, yield, and cluster weight. Moreover, the wine produced from the silica-treated grapes were ranked better in sensory evaluations. Our findings provide evidence for the potential of at least partially replacing conventional fungicides, rendering viticulture more sustainable in terms of soil protection and biodiversity. Silicon applications are low in costs and comply with the principles of organic wine production.
Prispevek na podlagi širokega pregleda literature obravnava vlogo silicija pri rastlinah, od same pojavnosti silicija v tleh preko mehanizmov privzema in prenosa, do nalaganja in deleža silicija v rastlinah. Članek nadalje zajema evolucijski vidik pojavnosti silicija pri rastlinah ter izpostavlja njegove ključne vloge pri uspevanju rastlin in blaženju negativnih učinkov številnih stresnih dejavnikov ter njegovo uporabnost v kmetijstvu.
Basic substances are a group of substances that have recently been regulated to give legislative coverage to common products such as vinegar, beer, milk and sugar, traditionally used by farmers for crop protection, and which may also include foodstuffs. They are regulated by article 23 of Regulation (EC) N. 1107/2009 concerning the placing of plant protection products on the market. According to this article, basic substances are not predominantly used as plant protection products but may be of value for plant protection. They do not have an immediate or delayed harmful effect on human or animal health nor an unacceptable effect on the environment. This review analyses the process for approval for basic substances under current European rules. Furthermore, every approved basic substance in the EU, at the time of writing, is described in detail in relation to its activity in plant protection. Considering that the use of basic substances is particularly important for organic farming, basic substances authorized in organic production under current organic legislation and under the new Regulation (EU) 2018/848 on organic production that will apply from 1 January 2022 repealing Council Regulation (EC) N. 834/2007 are reported. Finally, the review highlights the positive aspects and critical issues of basic substances.
The efficacies of tebuconazole plus azoxystrobin/Reynoutria spp. extract, sulfur (S)/Reynoutria spp. extract, Reynoutria spp. Extract/S, KH2PO4 plus S, Na2SiO3 (moduli m2 and m3) plus S, and NaHCO3 against powdery mildew caused by Erysiphe corylacearum were investigated on the hazelnut cultivars Kara and Sarı. The study was carried out during the 2019 vegetation season in a hazelnut orchard in the Akçakoca district of Düzce, Turkey. The experiment was established in a randomized complete block design with three replications, and twelve plants in two plantings (ocaks) were used for each parcel. The data on different parameters were analyzed using Minitab® Statistical Software Release 19, and the mean values were compared by the Tukey multiple range test (P≤ 0.05). The alternation treatment program of tebuconazole plus azoxystrobin/Reynoutria spp. extract exhibited the highest efficacy (93.6%) against disease on the leaves of the Kara cultivar, followed by the other treatment programs with efficacies between 91.8% and 79.6%. On the leaves of the Sarı cultivar, the alternation treatment program tebuconazole plus azoxystrobin/Reynoutria spp. extract, with 96.2%, and the mixing treatment program KH2PO4 plus S, with 94.9%, showed the highest effectiveness, followed by the application programs Na2SiO3 (m3) plus S, Na2SiO3 (m2) plus S, and S/Reynoutria spp. extract, with efficacies of 92.5%, 92.2%, and 91.3%, respectively. Na2SiO3 (m3) plus S (100%), S/Reynoutria spp. extract (94.6%), and Na2SiO3 (m2) plus S (93.9%) were most effective against powdery mildew on the fruit clusters of the Kara cultivar, and Na2SiO3 (m2) plus S (98.7%), KH2PO4 plus S (97.8%), and Na2SiO3 (m3) plus S (94.9%) had the highest efficacies on the fruit clusters of the Sarı cultivar, followed by tebuconazole plus azoxystrobin/Reynoutria spp. extract and KH2PO4 plus S on the Kara cultivar, and tebuconazole plus azoxystrobin/Reynoutria spp. extract and S/Reynoutria spp. extract on the Sarı cultivar. Reynoutria spp. extract/S showed moderate efficacies between 65.0% and 79.6% against powdery mildew on the leaves and fruit clusters. While NaHCO3 had moderate or high efficacies on the leaves of both cultivars (80.4% on the Kara cultivar and 57.9% on the Sarı cultivar), its effects were the lowest than those of other all treatment programs on the fruit clusters. The treatment programs had no phytotoxic effects on the leaves or fruit clusters of either hazelnut cultivar. The present study has demonstrated that all spraying programs except NaHCO3 could be used effectively as eco-friendly spraying programs against powdery mildew in hazelnut.
Fungal diseases such as powdery mildew and bunch rots reduce yield and quality of grapes and affect chemical and sensory properties of wine. The effects of powdery mildew, downy mildew, botrytis bunch rot, and ripe rot on grape and wine quality are reviewed. Approaches to detection and quantification of fungal contamination are examined, including enzyme, immunological and DNA assays and spectroscopy. Such approaches offer efficient and or objective means of quantifying fungal contamination in the vineyard and at the winery to facilitate quality control and decisions about use of grapes. Alternatives to conventional fungicides for disease management and their effects on quality are examined also.
The effect of root or leaf applications of soluble Si on severity of grape (Vitis vinifera L.) powdery mildew [Uncinula necator (Schwein) Burrill] was determined. On potted plants, root-feeding at 1.7 m m Si had no effect on disease severity, but foliar sprays at 17 m m Si substantially reduced the number of mildew colonies that developed on inoculated leaves. Scanning electron micrographs showed that, on Si-sprayed leaves, hyphae did not develop in areas where thick Si deposits were present on the leaf surface; and where surface deposits were not present, Si was translocated laterally through the leaf and surrounded the appressoria. Leaves on plants that were fed Si via roots showed a similar deposition of Si surrounding the appressoria. On water-sprayed leaves and leaves from untreated plants, internal deposition of Si was more variable and generally less than on Si-sprayed or root-fed plants. Conidia germination and germtube development on agar media were weakly promoted by the presence of Si. Reduced severity of grape mildew by Si sprays may be partly due to a physical barrier to hyphal penetration and to a resistance response involving the lateral movement of Si and its deposition within the leaf at fungal penetration sites.
The effect of soluble potassium silicate applied to cucumber (Cucumis sativus L.), muskmelon (C. melo L.), and zucchini squash (Cucurbita pepo L.) on the severity of powdery mildew was examined. Application methods included amending nutrient solutions to a concentration of 1.7 m m Si and foliar sprays containing 1.7, 8.5, 17, and 34 m m Si. Untreated plants and plants sprayed with distilled water were used as controls. The leaves of all plants were inoculated with known concentrations of conidia of Sphaerotheca fuliginea (Schlecht.:Fr.) Poll. (cucumber and mu&melon) or Erysiphe cichoracearum DC.: Merat (zucchini squash) 1 day after the sprays were applied. Inoculated leaves on plants receiving the Si-amended nutrient solution or foliar sprays of ≥ 17.0 m m Si developed fewer powdery mildew colonies than those on control plants. Results of a separate experiment that included a potassium spray, indicated that the active ingredient of the potassium silicate sprays appears to be Si. Experiments to test the persistence of Si foliar sprays on cucumber demonstrated that a 17 m m Si spray applied 7 days before inoculation with S. fuliginea reduced mildew colony formation.
The distribution of silicon in the leaf epidermis of cucumber (Cucumis sativus L.) grown in hydroponic nutrient solutions supplemented with soluble silicates was examined using scanning electron microscopy and energy dispersive x-ray analysis. Silicon was found primarily in cells surrounding the bases of the trichome hairs. During infection by Sphaerotheca fuliginea (Schlecht.:Fr.) Poll., areas of host cell wall adjacent to the germinating hyphae showed altered surface morphology and high concentrations of silicon. Measurements of total hyphal length per colony showed the fungal colonies grown on silicate-treated plants were significantly smaller than fungal colonies grown on control plants. In the early stages of infection, the presence of high silicon surrounding colonies was correlated with lower fungal growth. Key words: silicon, x-ray analysis, hydroponics, Cucumis sativus, Sphaerotheca fuliginea.
Section I-Sampling, Fermentation, and Production Analysis.- 1 / Fruit Quality and Soluble Solids.- 2 / Alcoholometry.- 3 / Extract.- 4 / Hydrogen Ion (pH) and Fixed Acids.- 5 / Volatile Acids.- 6 / Carbohydrates: Reducing Sugars.- 7 / Phenolic Compounds and Wine Color.- 8 / Oxygen, Carbon Dioxide, and Ascorbic Acid.- Section II-Microbial Stability.- 9 / Sulftir Dioxide.- 10 / Sulfur Containing Compounds.- 11 / Other Preservatives: Sorbic Acid, Benzoic Acid, and Dimethyldicarbonate.- 12 / Wine Microbiology.- Section III-Chemical Stability.- 13 / Tartaric Acid and its Salts.- 14 / Copper.- 15 / Iron and Phosphorus.- 16 / Nitrogenous Compounds.- Section IV-Remedial Actions.- 17 / Fining and Fining Agents.- 18 / Correction of Tartrate Instabilities.- 19 / Removal of Copper and Iron-The Hubach Analysis.- Appendixes.- Appendix I /Chromatographic Techniques.- Appendix II /Laboratory Reagent Preparation.- Appendix III /Laboratory Media and Stains.
This laboratory demonstrates the operation of a wavelength-dispersive x-ray spectrometer (WDS) fitted to a scanning electron microscope (SEM) or electron probe microanalyzer (EPMA). The WDS has important advantages over the energy-dispersive spectrometer (EDS) in terms of the peak-to-background ratio, improved elemental sensitivity, and better energy resolution of characteristic x-ray peaks to avoid peak overlaps. Comparisons of the major characteristics of the WDS and EDS detectors will be made. More detailed background information may be found in SEMXM, Chapters 5–8.
Vitis vinifera L. cultivars Müller-Thurgau, Muscat Ottonel, Gewürztraminer, and Kerner were studied for 1 year to document changes in fruit terpene levels from berry stage to free-run and press-juice stages. Substantial amounts of free volatile terpenes (FVTs) and potentially volatile terpenes (PVTs) were lost between berry and juice stages. PVTs were higher in press juices of `Gewürztraminer' and `Muscat Ottonel' than in free-run juices. In another experiment, juices from `Miiller-Thurgau', `Muscat Ottonel', `Kerner', `Optima', `Pearl of Csaba', and `Siegerrebe', harvested 10 to 20 days after a designated initial harvest date, contained higher FVTs and PVTs than initially. A third experiment with `Kerner', `Müller-Thurgau', `Optima', and `Siegerrebe' found highest FVTs and PVTs in juices from grapes subjected to skin contact compared with grapes crushed and immediately pressed. Sensory evaluation showed aroma differences between wines from free-run and press juices of `Miiller-Thurgau' and `Muscat Ottonel', aroma and flavor differences due to harvest date for all cultivars except `Pearl of Csaba', and aroma and flavor differences due to skin contact for `Siegerrebe'.
