Benzothiadiazole enhances resveratrol and anthocyanin biosynthesis in grapevine, meanwhile improving resistance to Botrytis cinerea

Pre-harvest multiple treatments of grapevine (cv. Merlot) with the plant activator benzothiadiazole (BTH, 0.3 mM) enhanced trans-resveratrol content in berries by about 40%. An even more striking effect was observed on anthocyanin synthesis, particularly on malvidine 3-glucoside, malvidine 3-(6-O-acetyl)glucoside and malvidine 3-(6-O-p-coumaroyl)glucoside, whose amounts were more than doubled. These data were obtained with a novel and time-saving HPLC method, set up for the simultaneous detection of stilbenes and anthocyanins, using an RF-10Axl fluorimetric detector instrument, with excitation at 330 nm and emission at 374 nm, and a SPD-Avp UV detector with absorption at 520 nm. Furthermore, BTH treatments induced systemic acquired resistance in grapevine, as assessed by inoculating clusters from treated and untreated plants with Botrytis cinerea. Disease severity, estimated according to the percentage of infected berries per cluster, was significantly reduced in grapes from BTH-treated plants. These results indicate that BTH treatments, besides improving the content of two important classes of nutraceuticals, with their well-known antioxidant, antitumoral, and phytoestrogenic activities, could be exploited in vineyard to protect grape against gray mould infection, thereby limiting an excessive use of fungicides     

Induction of resistance to gray mold with benzothiadiazole modifies amino acid profile and increases proanthocyanidins in grape: primary versus secondary metabolism

Field treatments of grapevine (cv. Merlot) with the plant activator benzothiadiazole (BTH, 0.3 mM) induced resistance against gray mold caused by Botrytis cinerea. Both incidence and severity of the disease were reduced. The resistance was associated with an increase of total polyphenols in berry skins, in particular, the proanthocyanidin fraction, that increased up to 36%. The amino acid profile of leaves was also modified by treatments, particularly lysine, that augmented 4-fold. Other amino acids involved in resistance mechanisms to either biotic or abiotic stress increased as well. These results indicate that BTH treatments can be used to control gray mold, thereby limiting an excessive use of fungicides, and could be exploited to increase the content of micronutrients of high nutritional value, arising from both primary and secondary metabolisms.     

Saskatoon and wild blueberries have higher anthocyanin contents than other Manitoba berries

Studies have shown that anthocyanins present in berry fruits have some beneficial health effects such as reducing age-associated oxidative stress and possessing anti-inflammatory properties. Therefore, six Manitoba berries (wild blueberry, Saskatoon berry, raspberry, chokecherry, strawberry, and seabuckthorn) were studied for their anthocyanin compositions (mg/100 g) on dry weight basis. Saskatoon berry and wild blueberry showed a high content of total anthocyanins (562.4 and 558.3 mg/100 g, respectively) that were not significantly (P>0.05) different from each other. The corresponding values for other berries: raspberry (365.2 mg/100 g), chokecherry (177.39 mg/100 g), and strawberry (97.5 mg/100 g) were significantly different from each other (P<0.05), and the total anthocyanin content of seabuckthorn was negligible (0.84 mg/100 g). Fifteen major anthocyanins were isolated from Manitoba berries. Saskatoon berry and wild blueberry contained higher amounts of delphinidin 3-glucoside (Dp-3-glc), malvidin 3-glucoside (Mv-3-glc), and malvidin 3-galactoside (Mv-3-gal). Dp-3-glc was 263.8 (mg/100 g) in Saskatoon berry and 84.4 (mg/100 g) in wild blueberry, whereas the corresponding values for Mv-3-glc in these berries were 47.4 and 139.6 (mg/100 g), respectively. Raspberry, strawberry, and chokecherry contained higher amounts of cyanidin 3-glucoside (Cy-3-glc), cyanidin 3-rutinoside (Cy-3-rut), and pelargonidin 3-glucoside (Pg-3-glc). The total anthocyanin content of Manitoba fruits followed the order: Saskatoon berry and blueberry (high anthocyanin berries), raspberry and chokecherry (medium anthocyanin berries), strawberry (low anthocyanin berries), and seabuckthorn (negligible anthocyanin berries). This study demonstrated that Saskatoon berries and wild blueberries have high potential value for fruit growers as well as the food and nutraceutical manufacturers because of their high anthocyanin contents.     

Ectopic expression of anthocyanin 5-o-glucosyltransferase in potato tuber causes increased resistance to bacteria

The principal goal of this paper was to investigate the significance of anthocyanin 5-O-glucosyltransferase (5-UGT) for potato tuber metabolism. The ectopic expression of a 5-UGT cDNA in the tuber improved the plant's defense against pathogen infection. The resistance of transgenic lines against Erwinia carotovora subsp. carotovora was about 2-fold higher than for nontransformed plants. In most cases the pathogen resistance was accompanied by a significant increase in tuber yield. To investigate the molecular basis of transgenic potato resistance, metabolic profiling of the plant was performed. In tuber extracts, the anthocyanin 3,5-O-substituted level was significantly increased when compared to that of the control plant. Of six anthocyanin compounds identified, the highest quantity for pelargonidin 3-rutinoside-5-glucoside acylated with p-coumaric acid and peonidin 3-rutinoside-5-glucoside acylated with p-coumaric acid was detected. A significant increase in starch and a decrease in sucrose level in transgenic tubers have been detected. The level of all other metabolites (amino acids, organic acids, polyamines, and fatty acids) was quite the same as in nontransformants. The plant resistance to bacterial infection correlates with anthocyanin content and sucrose level. The properties of recombinant glucosyltransferase were analyzed in in vitro experiments. The enzyme kinetics and its biochemical properties were similar to those from other sources.     

Influence of vine vigor on grape (Vitis vinifera L. Cv. Pinot Noir) anthocyanins. 2. Anthocyanins and pigmented polymers in wine

The relationships between grapevine (Vitis vinifera) vigor variation and resulting wine anthocyanin concentration and composition and pigmented polymer formation were investigated. The study was conducted in a commercial vineyard consisting of the same clone, rootstock, age, and vineyard management practices. Vine vigor parameters were used to designate vigor zones within two vineyard sites (A and B) to produce research wines (2003 and 2004) and conduct a model extraction experiment (2004 only) to investigate the vine-fruit-wine continuum. Wines and model extracts were analyzed by HPLC and UV-vis spectrophotometry. For the model extractions, there were no differences between sites for pomace weight, whereas juice volume was higher for site A. This was not related to a larger berry size. Site A had a higher anthocyanin concentration (milligrams per liter) in the model extracts than site B specifically for the medium- and low-vigor zones. For anthocyanin composition in the model extraction, site B had a greater proportion of malvidin-3-O-glucoside and less of the remaining anthocyanin glucosides (delphinidin, cyanidin, petunidin, and peonidin) compared to site A. In the wines, there was a vintage effect, with the 2003 wines having a higher anthocyanin concentration (milligrams per liter) than the 2004 wines. This appears to have been primarily due to a greater accumulation of anthocyanins in the fruit. In general, the medium-vigor zone wines had higher anthocyanin concentrations than either the high- or low-vigor zone wines. There was also vintage variation related to anthocyanin composition, with the 2003 wines having a higher proportion of delphinidin and petunidin glucosides and lower malvidin-3-O-glucoside compared to 2004. In both years, there were higher proportions of delphinidin and petunidin glucosides in wines made from low-vigor-zone fruit. Wines made from low-vigor zones showed a greater propensity to form vitisin A as well as pigmented polymers. Low-vigor-zone wines had a approximately 2-fold increase in pigmented polymer concentration (milligrams per liter) over high-vigor-zones wines. There was a strong positive relationship between pigmented polymer concentration, bisulfite bleaching resistant pigments, proanthocyanidin concentration, and color density in wines. Overall, differences found in the wines magnified variation in the fruit.     

Solar UV-B and ABA are involved in phenol metabolism of Vitis vinifera L. increasing biosynthesis of berry skin polyphenols

It has been previously found that abscisic acid (ABA) participates in the activation of grapevine leaf tissue defense against potentially damaging effects of solar ultraviolet-B radiation (UV-B), apparently by triggering biosynthesis of phenols that filter the harmful radiation and act as antioxidants. The present work studies the effect of solar UV-B and exogenously applied ABA on berry growth, sugar accumulation, and phenol (anthocyanin and nonanthocyanin) profiles across berry development and ripening of Vitis vinifera L. cv. Malbec in a vineyard at 1450 m of altitude. The grapevines were exposed to relatively high UV-B irradiation (normal sunlight; +UV-B) and also to a reduced UV-B treatment (filter exclusion; -UV-B). These two UV-B treatments were combined with weekly spray applications to the leaves and berries of 1 mM ABA (+ABA) or H(2)O (-ABA). Reduction of UV-B delayed berry development and maturation, whereas the +UV-B and +ABA combined treatment hastened berry sugar and phenol accumulation. +UV-B/+ABA treatments also reduced berry growth and decreased sugar per berry without affecting sugar concentration (°Brix) at harvest. Berry skin ABA levels were higher in the +UV-B and +ABA combined treatment, which also hastened the onset of ripening up to 20 days. Berry skin ABA levels then decreased toward harvest, implying a possible role for ABA in the control of ripening in this nonclimacteric fruit. Under both +UV-B and +ABA treatments berry skin phenols were additively increased with a change in anthocyanin and nonanthocyanin profiles and increases in the proportion of phenols with high antioxidant capacity.     

Carotenoid compounds in grapes and their relationship to plant water status

The aim of this work was to study the relationship between carotenoid contents in grapevine berries and plant water status. For this purpose, a black grapevine variety, Vitis vinifera L. cv. Touriga Nacional, was studied. The experiments were carried out in the same Douro vineyards, with plants of the same age, in two different water retention soils. A higher water retention capacity soil, soil A, and a lower water retention capacity soil, soil B, were both in a 1.2 m deep silt-loam schist-derived soil. The training system was the double cordon trained and spur pruned. A first range was nonirrigated (NI) and a second one was irrigated (I), 60% of evapotranspiration (ET(0)). For soil B, a 30% of ET(0) treatment was also applied. The plant water status was estimated by predawn leaf water potential. The effects of plant water status on berry growth were studied by measurement of the berry weight and total soluble solids (degrees Brix). The carotenoid profile was quantitatively determined by high-performance liquid chromatography/diode array. Carotenoids determined were beta-carotene, lutein, neoxanthin, violaxanthin, and luteoxanthin. The comparison between irrigated and nonirrigated grapes was followed from 2 weeks before veraison until the ripe stage. Results showed that at harvest time, berries exposed to the NI had a lower weight than those exposed to the irrigated treatment (60% of ET(0)), 0.89 vs 1.36 g/berry and 0.94 vs 1.34 g/berry, for soils A and B, respectively. The irrigated treatment contributed to a higher sugar concentration in both soils. However, depending on the soil water retention capacity, the carotenoid contents were different in soils A and B. For soil A, the total carotenoid content was similar for both NI and I treatments. However, with regard to soil B, in irrigated treatment, levels of carotenoids were approximately 60% lower than those found for the NI. It seems to be possible to produce higher weight berries (with higher sugar levels) with similar carotenoid contents. On the other hand, soil characteristics had a larger influence than irrigation on the concentration of carotenoids in grapes, resulting in an important viticultural parameter to take into account in aroma precursor formation.     

苯并噻二唑(BTH)诱导小麦对条锈病抗性的研究

小麦条锈病是小麦生产中的重要病害之一,为了明确苯并噻二唑(Benzothiadiazole,BTH)对小麦条锈病的诱导抗性作用,分别以BTH处理后的苗期和成株期小麦为试验材料,诱发接种小麦条锈菌后调查小麦的发病情况及防治效果。温室苗期试验结果表明,与对照相比,不同浓度BTH处理后,小麦抗锈性明显提高,病情指数降低29.69~49.77,防治效果可高达90%左右,不同浓度处理之间有一定差异,但与对照相比差异极显著;BTH诱导的最佳浓度为0.3 mmol·L-1,BTH喷雾处理后6~7 d小麦诱导抗锈性表达最强,诱导抗性的持久期在15 d以上。田间成株期试验结果表明,不同浓度处理诱导的小麦抗锈性无明显差异,浓度为0.3 mmol·L-1的BTH诱导处理小区小麦的产量最高,千粒重最重,为42.21 g,增产最高达19.3%。小麦在分蘖期、拔节前期和分蘖期+拔节前期喷施BTH,都能诱导小麦抗条锈性增强,病情指数显著降低,防治效果分别为43.07%、47.43%和50.01%,增产13.4%~16.9%。综上所述,BTH可以诱导小麦产生抗锈性,对小麦条锈病防治起到积极作用。     

水氮处理对荒漠绿洲区酿酒葡萄光合特性与产量的影响

研究水氮耦合对葡萄树光合、果实品质及产量变化的影响,对于发展葡萄产业具有科学指导意义。本研究利用Li-6400便携式光合仪,在葡萄浆果成熟期对不同水分亏缺及施氮水平下的酿酒葡萄进行了光合日变化测定,同时对可溶性固形物及产量进行测定。结果表明,土壤水分亏缺会导致气孔导度、蒸腾速率及光合速率的下降,而施氮量的增加能消减下降趋势。低氮条件下,轻度和重度水分亏缺分别使葡萄产量降低32.2%和49.9%,使浆果可溶性固形物含量分别提高6.9%和13.9%;氮素充足条件下,尽管存在水分亏缺,但葡萄产量无显著降低,且浆果可溶性固形物含量提高16.2%。该研究对于认识葡萄水肥耦合关系、指导水肥管理实践提供了理论依据。     

Berry phenolic extracts modulate the expression of p21(WAF1) and Bax but not Bcl-2 in HT-29 colon cancer cells

Previous studies have shown that anthocyanin-rich berry extracts inhibit the growth of cancer cells in vitro. The objective of this study was to compare the effects of berry extracts containing different phenolic profiles on cell viability and expression of markers of cell proliferation and apoptosis in human colon cancer HT-29 cells. Berry extracts were prepared with methanol extraction, and contents of the main phenolic compounds were analyzed using HPLC. Anthocyanins were the predominant phenolic compounds in bilberry, black currant, and lingonberry extracts and ellagitannins in cloudberry extract, whereas both were present in raspberry and strawberry extracts. Cells were exposed to 0-60 mg/mL of extracts, and the cell growth inhibition was determined after 24 h. The degree of cell growth inhibition was as follows: bilberry > black currant > cloudberry > lingonberry > raspberry > strawberry. A 14-fold increase in the expression of p21WAF1, an inhibitor of cell proliferation and a member of the cyclin kinase inhibitors, was seen in cells exposed to cloudberry extract compared to other berry treatments (2.7-7-fold increase). The pro-apoptosis marker, Bax, was increased 1.3-fold only in cloudberry- and bilberry-treated cells, whereas the pro-survival marker, Bcl-2, was detected only in control cells. The results demonstrate that berry extracts inhibit cancer cell proliferation mainly via the p21WAF1 pathway. Cloudberry, despite its very low anthocyanin content, was a potent inhibitor of cell proliferation. Therefore, it is concluded that, in addition to anthocyanins, also other phenolic or nonphenolic phytochemicals are responsible for the antiproliferative activity of berries.     

Novel benzo-1,2,3-thiadiazole-7-carboxylate derivatives as plant activators and the development of their agricultural applications

Plant activators are a novel kind of agrochemicals that could induce resistance in many plants against a broad spectrum of diseases. To date, only few plant activators have been commercialized. In order to develop novel plant activators, a series of benzo-1,2,3-thiadiazole-7-carboxylate derivatives were synthesized, and the structures were characterized by (1)H NMR, IR, elemental analyses, and HRMS or MS. Their potential systemic acquired resistance as plant activators was evaluated as well. Most of them showed good activity, especially, fluoro-containing compounds 3d and 3e, which displayed excellent SAR-inducing activity against cucumber Erysiphe cichoracearum and Colletotrichum lagenarium in assay screening. Field test results illustrated that compounds 3d and 3e were more potent than the commercial plant activator, S-methyl benzo[1,2,3]thiadiazole-7-carbothioate (BTH) toward these pathogens. Further, the preparation of compound 3d is more facile than BTH with lower cost, which will be helpful for further applications in agricultural plant protection.     

Improving grape phenolic content and wine chromatic characteristics through the use of two different elicitors: methyl jasmonate versus benzothiadiazole

Benzothiadiazole (BTH) and methyl jasmonate (MeJ) have been described as exogenous elicitors of some plant defense compounds, polyphenols among them. The objective of this study was to determine whether the application of BTH or MeJ to grape clusters at the beginning of the ripening process had any effect on the accumulation of the main flavonoid compounds in grapes (anthocyanins, flavonols, and flavanols) and the technological significance of these treatments in the resulting wines. The results obtained after a 2 year experiment indicated that both treatments increased the anthocyanin, flavonol, and proanthocyanidin content of grapes. The wines obtained from the treated grapes showed higher color intensity and total phenolic content than the wines made from control grapes. The exogenous application of these elicitors, as a complement to fungicide treatments, could be an interesting strategy for vine protection, increasing, at the same time, the phenolic content of the grapes and the resulting wines.     

Different polyphenolic components of soft fruits inhibit alpha-amylase and alpha-glucosidase

Polyphenol-rich extracts from soft fruits were tested for their ability to inhibit alpha-amylase and alpha-glucosidase. All extracts tested caused some inhibition of alpha-amylase, but there was a 10-fold difference between the least and most effective extracts. Strawberry and raspberry extracts were more effective alpha-amylase inhibitors than blueberry, blackcurrant, or red cabbage. Conversely, alpha-glucosidase was more readily inhibited by blueberry and blackcurrant extracts. The extent of inhibition of alpha-glucosidase was related to their anthocyanin content. For example, blueberry and blackcurrant extracts, which have the highest anthocyanin content, were the most effective inhibitors of alpha-glucosidase. The extracts most effective in inhibiting alpha-amylase (strawberry and raspberry) contain appreciable amounts of soluble tannins. Other tannin-rich extracts (red grape, red wine, and green tea) were also effective inhibitors of alpha-amylase. Indeed, removing tannins from strawberry extracts with gelatin also removed inhibition. Fractionation of raspberry extracts on Sephadex LH-20 produced an unbound fraction enriched in anthocyanins and a bound fraction enriched in tannin-like polyphenols. The unbound anthocyanin-enriched fraction was more effective against alpha-glucosidase than the original extract, whereas the alpha-amylase inhibitors were concentrated in the bound fraction. The LH-20 bound sample was separated by preparative HPLC, and fractions were assayed for inhibition of alpha-amylase. The inhibitory components were identified as ellagitannins using LC-MS-MS. This study suggests that different polyphenolic components of fruits may influence different steps in starch digestion in a synergistic manner.     

Soil properties,but not plant nutrients (N,P, K) interact with chemically induced resistance against powdery mildew in barley

Chemically induced resistance is a promising method of plant protection against diseases, which can be triggered by systemically acting chemical inducers such as BTH (benzo(1, 2, 3)thiadiazole‐carbothioic‐acid‐S‐methylester). BTH is commercially distributed as a 50 % formulation, called Bion®. The uncertain success of Bion® application in controlling infection by powdery mildew is a major obstacle in using induced resistance for plant protection in agriculture. This study aimed to investigate the effect of soil properties, selected macronutrients (N, P, and K), and addition of organic matter on induced resistance and to identify possible factors responsible for the high variability of BTH effect under field conditions. A pot experiment under open‐air conditions was set up using the pathosystem Hordeum vulgare cv. Ingrid / Blumeria graminis f. sp. hordei race A6. The different soils strongly affected the resistance of barley plants against powdery mildew after BTH treatment. The infection of barley by powdery mildew was lower than on all other soils when grown on an acid forest soil which was limed up to pH 4.9, even after BTH treatment. A reproducible induction of pathogen resistance by BTH was shown only on a mineral soil (Kleinlinden) with a negligible C content. Application of N, P, and K did not consistently affect the induction of resistance by BTH. The addition of green manure and compost led to an enhanced variability of resistance induction on the soil “Kleinlinden”. Possible effects of soil microflora on resistance induction are discussed.     

A multivariate approach for the ampelographic discrimination of grapevine (<Emphasis Type="Italic">Vitis vinifera</Emphasis>) cultivars: application to local Syrian genetic resources

Due to its unique historical and geographical emplacement, grapes have been cultivated in the Syrian Arab Republic for more than 5000 years, so the characterization of its local genetic resources is paramount for understanding grapevine natural diversity. In this work, different local Syrian table grape cultivars were characterized for 42 traits related to plant phenology, shoot, leaf, cluster, berry and juice composition. A series of multivariate analyses were sequentially performed, and five highly-discriminant traits were identified as the most discriminant ones (shoot internode length, berry weight, berry elongation, 100-seed weight and juice titratable acidity). The clustering of the cultivars according to these five traits revealed that some local Syrian cultivars share similitude with some worldwide grown cultivars, suggesting their potential as new genetic resources for the development of new high-quality table grape varieties, and indicating the needing of specific preservation programs aimed to avoid the loss of endangered genetic local resources. Besides, the statistical multivariate pipeline followed in this work is proposed as an efficient one for the selection of ampelographic traits for the discrimination of grapevine cultivars.     

BTH诱导番茄耐番茄斑萎病毒(TSWV)研究

番茄斑萎病毒(Tomato Spotted Wilt Orthotospovirus,TSWV)是番茄生长过程中发生严重的病毒病之一,严重威胁世界各地番茄的安全生产。为了研究植物诱导抗性在番茄抗TSWV中的防御作用,本研究以矮番茄为研究对象,使用苯并噻二唑(BTH)前处理番茄植株,研究BTH诱导的TSWV抗性,并分析BTH处理番茄植株后的发病严重度、病毒含量、植株抗氧化能力、质膜稳定性、细胞的解离情况,以及SlMAPK1、SlMAPK2和SlMAPK3的表达量。结果表明,0.1 mmol·L^-1BTH前处理番茄植株能够诱导丝裂原活化蛋白激酶级联信号通路关键基因SlMAPK1、SlMAPK2和SlMAPK3的表达,提高细胞抗氧化酶活性及质膜稳定性,并减轻病毒对细胞的破坏,从而增强番茄植株对TSWV耐性,抑制TSWV在番茄植株中的复制,BTH前处理植株发病的严重度显著低于对照。本研究为诱导植物抗病毒研究奠定理论基础。     

Champagne wine polyphenols protect primary cortical neurons against peroxynitrite-induced injury

White wines are generally low in polyphenol content as compared to red wines. However, Champagne wines have been shown to contain relatively high amounts of phenolic acids that may exert protective cellular actions in vivo. In this study, we have investigated the potential neuroprotective effects of Champagne wine extracts, and individual phenolics present in these extracts, against peroxynitrite-induced injury. Organic and aqueous Champagne wine extracts exhibited potent neuroprotective activity against peroxynitrite-induced injury at low concentrations (0.1 microg/mL). This protection appeared to be in part due to the cellular actions of individual components found in the organic extracts, notably tyrosol, caffeic acid, and gallic acid. These phenolics were observed to exert potent neuroprotection at concentrations between 0.1 and 10 microM. Together, these data suggest that polyphenols present in Champagne wine may induce a neuroprotective effect against oxidative neuronal injury.     

BTH诱导番茄耐番茄斑萎病毒(TSWV)研究

番茄斑萎病毒(Tomato Spotted Wilt Orthotospovirus,TSWV)是番茄生长过程中发生严重的病毒病之一,严重威胁世界各地番茄的安全生产。为了研究植物诱导抗性在番茄抗TSWV中的防御作用,本研究以矮番茄为研究对象,使用苯并噻二唑(BTH)前处理番茄植株,研究BTH诱导的TSWV抗性,并分析BTH处理番茄植株后的发病严重度、病毒含量、植株抗氧化能力、质膜稳定性、细胞的解离情况,以及SlMAPK1、SlMAPK2和SlMAPK3的表达量。结果表明,0.1 mmol·L^-1BTH前处理番茄植株能够诱导丝裂原活化蛋白激酶级联信号通路关键基因SlMAPK1、SlMAPK2和SlMAPK3的表达,提高细胞抗氧化酶活性及质膜稳定性,并减轻病毒对细胞的破坏,从而增强番茄植株对TSWV耐性,抑制TSWV在番茄植株中的复制,BTH前处理植株发病的严重度显著低于对照。本研究为诱导植物抗病毒研究奠定理论基础。     

Wachstum und Reife der Weinbeere

Growth and ripening of berry grapes Berry enlargement shows a characteristical double-sigmoid curve. It can be shown that there was an increase up to a maximum in the amount of endogenous auxin and cytokinin during the period of the first berry growth and a sudden decrease after having attained a short stop of berry growth. Accumulation of sugars in the fruits begins during period I1 of growth enlargement, at the same time the content of ABA increases. Possible relations between phytohormonal regulation of berry growth and the role of plant hormones as to translocation of carbohydrates from the leaves into the berries are discussed.     

Effects of Foliar Fertilization on Incidence of Berry Shrivel and Bunch Stem Necrosis in Vitis vinifera L. CVS ‘Pinot Blanc’ and ‘Zweigelt’

Berry shrivel and bunch stem necrosis are the economically most important physiological disorders of grapevine. The nutritional status of the plant is considered as one of the main elicitors for the occurrence of these disorders. For foliar fertilization trials, two vineyards that had previously been affected by both diseases were selected in Southwest Germany, one with the variety ‘Zweigelt’ and one with Pinot Blanc. By the use of potassium, magnesium, and calcium foliar fertilizers, a rapid increase of different nutrients in the plants should be caused and the effects on the diseases observed. In 2010, no significant differences in the fertilization treatments were found for both varieties. In ‘Pinot Blanc’, significantly more berries were affected by berry shrivel in 2011 in plots treated with calcium fertilizer compared to those treated with potassium and magnesium. Plots with magnesium fertilizer showed significantly less berries affected by berry shrivel than the untreated control.