Fact-checked by Grok 2 weeks ago

Uncinula necator

Uncinula necator, currently classified as Erysiphe necator, is an ascomycete fungus responsible for powdery mildew, a major disease that infects grapevines (Vitis species) and impacts viticulture worldwide.^[1]^[2] This pathogen, native to North America, has spread globally and thrives in warm, humid conditions, causing significant economic losses through reduced yields, berry quality degradation, and off-flavors in wine.^[2]^[3] The fungus produces white, powdery mycelial growth on infected tissues, including leaves, shoots, flowers, and berries, which can lead to distorted leaves, cracked or shriveled fruit, and premature defoliation.^[1]^[3] Unlike some fungal diseases, it does not require free water for infection but spreads via airborne conidia under high humidity (40–100%) and temperatures between 59°F and 90°F, with optimal growth at 68–77°F.^[2]^[3] E. necator overwinters primarily as dormant cleistothecia—small, reddish-black fruiting bodies—in bark crevices or on canes, releasing ascospores in spring triggered by rain (as little as 0.1 inch) and temperatures above 50°F.^[2]^[3] During the growing season, it produces chains of conidia on conidiophores, enabling rapid secondary spread within vineyards, particularly in shaded, dense canopies.^[2]^[3] Susceptible varieties such as Chardonnay, Merlot, and Cabernet Franc are especially vulnerable, with even 3–5% infected berries at harvest compromising wine quality.^[2]^[3] Management relies on cultural practices like canopy management for better airflow and sunlight exposure, alongside fungicide applications (e.g., sulfur or demethylation inhibitors) timed from early shoot growth through bloom, with rotation to prevent resistance.^[2]^[3] The fungus is sensitive to high temperatures above 32°C and alkaline pH over 8.0, which can inform non-chemical controls.^[1] Ongoing research emphasizes integrated pest management to mitigate its impact on global grape production.^[2]

Taxonomy and Nomenclature

Classification

Erysiphe necator (synonym Uncinula necator) belongs to the kingdom Fungi, phylum Ascomycota, class Leotiomycetes, order Erysiphales, and family Erysiphaceae.^[4] This placement situates it among the powdery mildew fungi, a group of obligate biotrophic ascomycetes characterized by their specialized parasitic adaptations. The genus Erysiphe is the largest in the Erysiphaceae, encompassing numerous species that infect a wide range of plants, with E. necator specifically adapted to Vitis hosts.^[5] Historically classified in the genus Uncinula, E. necator was reclassified into Erysiphe following phylogenetic studies based on nuclear ribosomal DNA internal transcribed spacer (ITS) sequences. These analyses revealed close genetic and morphological similarities between Uncinula species and the core Erysiphe clade, leading to the recognition of Uncinula as a section within Erysiphe rather than a distinct genus.^[5] The reclassification emphasized the monophyletic nature of the group, resolving earlier taxonomic ambiguities rooted in morphological criteria alone.^[5] The evolutionary origin of E. necator traces to North America, where phylogeographic analyses show the highest genetic diversity among populations, suggesting it co-evolved with wild Vitis species over an extended period. This co-evolution is evidenced by the pathogen's adaptation to native grapevines, with genetic bottlenecks observed in non-native regions indicating historical introductions.^[6] Introduced populations in Europe and elsewhere exhibit reduced variability, consistent with a single or few migration events from the native range.^[6] Diagnostic traits of E. necator include its ectoparasitic growth habit, in which hyphae develop superficially on host surfaces without penetrating cell walls for colonization, and the formation of haustoria that invaginate epidermal cells to facilitate nutrient uptake. Additionally, it produces dense, powdery masses of conidia on infected tissues, contributing to its characteristic white, effuse appearance and aiding in dispersal. These features distinguish it within the Erysiphales and underscore its obligate biotrophic lifestyle.^[7]

Synonyms and Reclassification

The fungus was originally described as Uncinula necator by Lewis David von Schweinitz in 1832, based on specimens collected from grapevines (Vitis spp.) in North America, with the formal publication appearing in 1834.^[8] This name reflected the distinctive uncinulate (hooked) appendages on the ascomata, a key morphological feature at the time.^[9] Several synonyms arose in the 19th century due to incomplete knowledge of the fungus's life cycle and morphology. Notably, Oidium tuckeri Berk. was proposed in 1847 for the anamorphic (asexual) stage observed on grapevines in England, while Uncinula americana Howe and Uncinula spiralis Berk. & Curt. described similar forms in North America, all later recognized as conspecific with U. necator.^[9] These synonyms highlighted early confusion between sexual (teleomorph) and asexual (anamorph) states, common in powdery mildew fungi before integrated taxonomic approaches.^[10] In 2002, a comprehensive taxonomic revision reclassified Uncinula necator as Erysiphe necator, integrating it into the genus Erysiphe as section Uncinula based on molecular phylogenetic analyses. This shift was driven by sequence data from the internal transcribed spacer (ITS) regions and 28S rDNA, which demonstrated that Uncinula species formed a monophyletic clade within Erysiphe, closer to other Erysiphe lineages than to traditional Uncinula boundaries defined by appendage morphology alone. The revision emphasized evolutionary relationships over superficial traits, resolving long-standing uncertainties in powdery mildew taxonomy. Despite the reclassification, Uncinula necator persists in much of the viticulture literature due to historical precedence and familiarity among practitioners, particularly in applied disease management contexts.^[11] However, Erysiphe necator is the officially accepted name by major mycological authorities, including Index Fungorum, as of 2025, reflecting consensus on its phylogenetic placement.^[8] The nomenclature of E. necator was further influenced by debates surrounding teleomorph-anamorph naming under the 2011 International Code of Nomenclature for algae, fungi, and plants (ICN). The code's amendments, stemming from the Amsterdam Declaration, abolished dual nomenclature for pleomorphic fungi, requiring a single name per species regardless of reproductive state and prioritizing the earliest legitimate teleomorph name.^[12] For E. necator, this resolved potential conflicts between Uncinula (teleomorph) and Oidium tuckeri (anamorph), standardizing Erysiphe necator and simplifying research across fungal taxonomy.^[13]

Morphology and Reproduction

Asexual Phase

The asexual phase of Uncinula necator (syn. Erysiphe necator) involves the production of conidia from superficial hyphae on infected host tissues, enabling rapid clonal propagation during the growing season. Conidiophores emerge erect and perpendicular from the mycelium, typically measuring 10–400 µm in height and becoming multiseptate as they mature. These structures bear chains of hyaline, barrel-shaped to cylindro-ovoid conidia, each approximately 27–47 µm long and 14–21 µm wide, with 1–2 large vacuoles that form cyclically over 24 hours.^[7] The conidia are released singly or in short chains, particularly under still air conditions, contributing to the characteristic white, powdery appearance of mildew colonies that manifest as circular, felt-like patches ranging from a few millimeters to over 1 cm in diameter on leaves, shoots, and berries.^[7] Conidia serve as the primary inoculum for secondary infections, dispersing primarily by wind over short and long distances to initiate new outbreaks within vineyards. Upon landing on susceptible host surfaces, conidia germinate rapidly, often within hours, by producing a single germ tube that terminates in a lobed appressorium for direct penetration of the epidermis, or occasionally via direct hyphal emergence.^[7] Germination is optimal at temperatures of 20–25°C and relative humidities between 40% and 100%, with reduced efficiency under direct sunlight or UV exposure due to desiccation.^[14] This process allows the fungus to colonize new tissues efficiently, forming visible colonies within 5–9 days post-inoculation.^[15] The polycyclic nature of the asexual phase drives epidemic development, with conidial production enabling multiple infection cycles per season—typically 10 or more generations under favorable conditions in temperate climates. Each cycle amplifies disease severity through repeated dispersal and colonization, underscoring the phase's central role in the pathogen's epidemiology.^[16]

Sexual Phase

The sexual phase of Uncinula necator (syn. Erysiphe necator) involves the formation of chasmothecia, also known as pseudothecia or cleistothecia, which develop late in the growing season on the surface of infected grapevine tissues, typically from mid-August to mid-November in temperate regions.^[17] These structures initiate as white, immature bodies that mature through yellow and brown stages to become spherical, dark brown to black fruiting bodies, anchored initially by hyphae that degrade upon maturity.^[17] Chasmothecia measure 80-130 μm in diameter and feature a peridium composed of interwoven hyphae, with 20-40 hooked (uncinate) appendages arising from the equatorial region, which are septate, brownish, and 1-6 times the length of the chasmothecium; these appendages, responsible for the original genus name Uncinula, aid in attachment to host debris.^[9]^[18] Each chasmothecium contains multiple asci (typically 1-5), with each ascus producing up to 8 ascospores through meiosis, though commonly 2-4 ascospores per ascus are observed; the ascospores are hyaline, elliptical to ovoid, and measure approximately 20–25 μm in length by 11–15 μm in width.^[9]^[19]^[20] The onset of the sexual phase is triggered by environmental cues such as shortening photoperiods and declining temperatures in late summer to autumn, promoting the differentiation of hyphae into chasmothecia under conditions of high disease pressure on senescing tissues.^[21] Maturation of ascospores within chasmothecia requires accumulation of approximately 153 degree-days (base 10°C) post-bud break, with about 34% containing mature ascospores before leaf fall and the remainder maturing overwinter.^[17] These chasmothecia overwinter on fallen leaves, bark, or vine debris, serving as primary survival structures.^[17] Ascospore release occurs primarily in spring, from bud break through bloom, initiated by rainfall events exceeding 2 mm or prolonged wet periods of at least 3.5 hours, which cause the chasmothecia to rupture and discharge ascospores ballistosporically over distances of several centimeters.^[17]^[22] The fungus is heterothallic, requiring compatible mating types (groups A and B) for chasmothecium formation, and meiosis during ascospore production enables genetic recombination, generating diverse progeny that can introduce variability in traits such as fungicide resistance, including mutations like A495T in the CYP51 gene associated with demethylation inhibitor (DMI) resistance.^[23]^[24] This recombination contributes to the evolution of resistant strains, with sexual reproduction observed in up to 20% of chasmothecia populations in some regions.^[23]

Hosts and Disease Symptoms

Host Range

Uncinula necator, now classified as *Erysiphe necator_, primarily infects Vitis vinifera, the European grapevine cultivated for wine production worldwide. This species serves as the main host, with the fungus causing significant economic losses in viticulture regions due to its high susceptibility. ^[9] The pathogen also affects wild Vitis species native to North America, such as V. labrusca (fox grape) and V. rupestris (sand grape), which can harbor infections and contribute to disease reservoirs in non-cultivated areas. ^[6] The host range of E. necator is restricted to the Vitaceae family, with natural infections primarily on Vitis; infections outside Vitis are rare and limited to specific reports in other genera such as Cissus. ^[25] ^[9] Natural infections have been reported on Cissus rhombifolia, for example in the Czech Republic, though these underscore the pathogen's specificity to Vitaceae. ^[9] Experimental inoculations have demonstrated limited infections on related genera like Parthenocissus and Ampelopsis, but natural occurrences remain unconfirmed for these. ^[26] Susceptibility varies markedly among Vitis cultivars and species. V. vinifera varieties are generally highly vulnerable, particularly on young tissues, leading to widespread disease in commercial vineyards. ^[27] In contrast, certain American rootstocks, such as those derived from V. riparia, exhibit partial resistance due to polygenic traits and specific loci like RUN1, which originates from V. rotundifolia (muscadine grape) and triggers hypersensitive responses limiting fungal growth. ^[28] Recent research has identified additional susceptibility loci, such as SEN2, contributing to variation in resistance among Vitis species.^[29] These genetic factors enable partial tolerance in hybrid rootstocks, though complete immunity is rare. ^[30] Originally native to North America, E. necator was introduced to Europe in 1845, likely via infected plant material, and rapidly spread to viticulture areas. ^[9] Its current global distribution aligns closely with temperate grape-growing regions, from Europe and North America to Asia and Australia, where suitable hosts and climates sustain populations. ^[31]

Symptoms and Pathological Effects

Uncinula necator, the causative agent of powdery mildew in grapevines, produces distinctive external signs characterized by a white, powdery growth of mycelium and conidia on infected tissues. This superficial fungal mat appears on the upper and lower surfaces of leaves, young shoots, and berries, often starting as small colonies that expand under favorable conditions. As the infection progresses, the powdery appearance may turn grayish or dusty, particularly on older lesions, due to the accumulation of conidia and mycelial remnants.^[32]^[33]^[34] On grape leaves, symptoms include chlorotic spots on the upper surface corresponding to areas of powdery growth below, leading to distorted growth in young foliage and premature leaf drop in severe cases. Infected shoots exhibit dark brown to black feathery lesions, while berries develop a white coating that causes surface scarring, cracking, and eventual shriveling or rot. These symptoms arise from the fungus's haustoria, which penetrate host cells to extract nutrients, impairing photosynthesis and overall plant vigor.^[32]^[34]^[33] Physiologically, U. necator infection reduces photosynthetic capacity through nutrient diversion and tissue damage, resulting in stunted vine growth and significant yield losses in susceptible varieties under unmanaged conditions, with potential for complete crop loss in severe epidemics.^[35] Berry composition is altered, with decreased soluble solids and increased acidity, which compromises ripening and leads to off-flavors in wine, including a characteristic fungal aroma from volatile compounds like 1-octen-3-ol.^[34]^[36]^[37] Secondary effects include weakened tissues that predispose grapes to infections by other pathogens, such as Botrytis cinerea causing bunch rot, particularly when berry cracking occurs from as little as 3-5% mildew incidence at harvest. This exacerbates quality degradation and post-harvest spoilage.^[2]^[33]^[2]

Life Cycle and Epidemiology

Infection Process

Uncinula necator, now classified as Erysiphe necator, initiates infection when conidia or ascospores land on the surface of susceptible host tissues, such as grapevine leaves or berries. Upon attachment, the spores germinate rapidly, producing a primary germ tube that differentiates into a lobed appressorium within 12-24 hours under favorable conditions. The appressorium generates turgor pressure, facilitating the emergence of a penetration peg that breaches the host's epidermal cell wall and cuticle without causing mechanical wounding. This direct penetration mechanism allows the fungus to enter the epidermal cells, establishing initial intracellular contact.^[38]^[39] Once inside the host cell, E. necator forms globose haustoria, specialized intracellular structures that invaginate the plant's plasma membrane and form an extrahaustorial matrix for nutrient exchange. These haustoria absorb essential nutrients, including hexoses and amino acids, from the host while secreting effector proteins that manipulate host physiology to sustain biotrophy. Concurrently, the fungus develops ectoparasitic mycelial growth on the leaf surface, with hyphae spreading superficially (4-5 µm in diameter) and producing additional appressoria to colonize adjacent cells. This superficial hyphal network supports colony expansion without deep tissue invasion.^[38]^[26]^[39] The latency period, from spore inoculation to the appearance of visible symptoms like white mycelial patches, typically spans 5-7 days at temperatures of 20-25°C, though it can extend to 25 days at cooler temperatures around 9°C. During this asymptomatic phase, the pathogen establishes a functional haustorial network while actively suppressing host defenses; for instance, haustorial effectors inhibit salicylic acid signaling pathways, preventing effective immune responses and promoting successful colonization. This manipulation ensures the fungus maintains a compatible interaction with the host, delaying necrosis and supporting prolonged nutrient acquisition.^[39]^[38]

Dispersal and Spread

Uncinula necator primarily spreads within and between vineyards through airborne dispersal of its conidia, the asexual spores produced abundantly on infected surfaces. Wind currents serve as the main vector, with dispersal initiated at speeds as low as 2.3 m s⁻¹ and increasing with higher velocities, allowing conidia to travel considerable distances across landscapes. Secondary local spread occurs via rain splash, where light precipitation (approximately 2 mm) dislodges conidia from colonies, and through mechanical transmission by vineyard machinery, pruning tools, or high-pressure pesticide applications that generate disruptive air currents.^[40]^[41]^[42] Long-distance propagation of U. necator has been facilitated by human activities, particularly the international trade of infected planting material. The pathogen was inadvertently introduced to Europe from North America in the mid-19th century, likely via imported rootstocks and cuttings, leading to its rapid establishment and spread across viticultural regions by the 1850s. This historical event exemplifies how global commerce can enable intercontinental dissemination, resulting in widespread epidemics where the fungus was previously absent.^[31]^[43]^[44] Epidemiological models describe U. necator dynamics as monocyclic for the initial infection phase driven by ascospores released from overwintering cleistothecia, transitioning to polycyclic cycles fueled by repeated conidial production and dispersal, which amplify disease severity under conducive conditions. These models highlight the pathogen's high reproductive potential, underscoring the risk of rapid epidemic buildup. Once conidia reach susceptible hosts, they initiate the infection process detailed in related sections.^[7] At the vineyard scale, dispersal patterns create distinct infection gradients, with disease severity increasing downwind from primary inoculum sources due to prevailing wind directions facilitating conidial deposition. Canopy density further modulates these gradients by altering airflow and creating microhabitats of elevated humidity that enhance spore survival and secondary infections, particularly in dense foliage that limits penetration of dry, dispersive winds.^[42]^[45]

Environmental Factors

Abiotic Influences

The development and infection success of Uncinula necator (syn. Erysiphe necator), the causal agent of grapevine powdery mildew, are profoundly influenced by abiotic factors such as temperature, humidity, and light exposure. These non-living environmental conditions dictate the pathogen's growth, sporulation, and dispersal, often determining epidemic potential in viticultural regions. Understanding these influences is essential for predicting disease outbreaks and implementing targeted management strategies. Temperature plays a pivotal role in fungal growth and conidial viability. U. necator exhibits growth across a range of 6–32°C, with optimal conditions for mycelial development and sporulation occurring between 20–25°C.^[46]^[47] Conidial germination is favored at 24–25°C, but viability declines sharply below 5°C, where metabolic processes slow, and above 35°C, where thermal stress inhibits germination and leads to conidial death after prolonged exposure.^[7]^[9] These thresholds explain the pathogen's prevalence in temperate growing seasons and its limitation in extreme heat or cold events. Relative humidity (RH) is another critical driver, with U. necator thriving at 40–100% RH without requiring free water for infection, distinguishing it from water-dependent pathogens like downy mildew (Plasmopara viticola).^[9] High humidity, particularly at night, facilitates ascospore release from overwintering cleistothecia, as rain events (as little as 0.1 inch or >2 mm) providing wetting durations exceeding 2.5 hours, combined with temperatures above 10–11°C, trigger dehiscence and dispersal.^[48]^[49] Light and ultraviolet (UV) radiation exert inhibitory effects on conidial germination and survival. Direct sunlight and UV-B exposure reduce germination rates by damaging conidial walls and DNA, with shaded environments within dense grapevine canopies promoting disease by minimizing these suppressive effects.^[50]^[7] This microclimatic preference underscores the pathogen's adaptation to humid, low-light interiors of foliage. Climate change is anticipated to exacerbate U. necator epidemics through warmer temperatures and altered humidity patterns in major viticulture zones. Projections indicate increased disease pressure by 2050, as rising global temperatures (up to 1.5–2°C) and more frequent humid conditions expand suitable niches for the pathogen, potentially leading to higher infection rates and yield losses in regions like Europe and North America.^[51]^[52]

Biotic Interactions

Uncinula necator, now classified as Erysiphe necator, engages in various biotic interactions that regulate its populations in vineyard ecosystems. Antagonistic organisms play a key role in suppressing the pathogen through direct parasitism or predation. The hyperparasitic fungus Ampelomyces quisqualis (syn. Ampelomyces spp.) is a prominent natural enemy, colonizing and lysing the intracellular mycelium of E. necator, thereby reducing conidial production and disease incidence. This mycoparasite has been commercialized as a biocontrol agent, such as AQ10, demonstrating efficacy in field applications against powdery mildew on grapes. Predatory mites, including mycophagous species like Anthoseius spp., feed on E. necator conidia and hyphae, providing biological control by limiting fungal spread; their populations are enhanced in minimally pruned vineyards with reduced pesticide use.^[53]^[54]^[55]^[56] Synergistic interactions with other organisms can exacerbate E. necator infections. Co-occurrence with Botrytis cinerea, the causal agent of gray mold, on grape berries often leads to compounded damage, where powdery mildew weakens berry skin integrity, facilitating B. cinerea invasion and increasing bunch rot severity. Arbuscular mycorrhizal fungi (AMF) form associations with grapevine roots, indirectly bolstering host resistance to E. necator by improving nutrient uptake and physiological stress tolerance, which enhances overall plant defense responses.^[57]^[58] Genetic interactions between E. necator and its hosts underpin resistance dynamics, resembling gene-for-gene models where pathogen avirulence factors match host resistance genes. In Muscadinia rotundifolia, the REN1 locus encodes a TIR-NB-LRR protein that triggers a hypersensitive response, restricting E. necator colonization upon recognition of specific pathogen effectors; this resistance is durable but can be overcome by virulent strains. Such dynamics highlight evolutionary arms races, with E. necator populations adapting via mutations in avirulence genes to evade host immunity.^[59]^[26]^[28] Microbial communities in vineyard soils and the grapevine phyllosphere modulate E. necator disease severity through competitive and antagonistic effects. Phyllosphere bacteria, such as Pseudomonas and Bacillus spp., can inhibit fungal germination via antibiotic production or nutrient competition, with elicitor applications shifting community composition to favor suppressive consortia. Soil microbiomes, including AMF and beneficial rhizobacteria, influence aboveground disease by enhancing root vigor and systemic resistance, often predicting powdery mildew incidence more effectively than foliar communities alone. These interactions underscore the potential of microbiome engineering for integrated disease management.^[60]^[61]^[62]

Management and Control

Cultural Practices

Cultural practices form a cornerstone of integrated pest management for Erysiphe necator in vineyards, emphasizing proactive measures to create unfavorable conditions for the pathogen's establishment and spread without relying on synthetic chemicals. These techniques focus on optimizing vineyard microclimates, disrupting the fungus's life cycle, and promoting vine health to minimize infection risks. By enhancing airflow, increasing sunlight exposure, and reducing humidity, growers can significantly lower disease pressure, particularly during vulnerable growth stages.^[63] Canopy management is essential for mitigating E. necator infections, as dense foliage creates humid, shaded microenvironments conducive to fungal growth. Practices such as shoot thinning—removing excess shoots early in the season (e.g., when vines reach 3-6 inches of growth)—and leaf removal in the fruit zone improve air circulation and UV penetration, which naturally suppress spore germination and pathogen viability. Shoot positioning on trellises, such as vertical shoot positioning, further opens the canopy to maintain balanced light distribution and reduce cluster humidity, with studies showing reduced infection rates in well-ventilated vineyards. These methods not only limit disease but also enhance spray coverage if supplemental controls are needed later. Additionally, avoiding excessive nitrogen fertilization prevents succulent growth that attracts infections, as balanced nutrition supports denser, more resistant tissues.^[63]^[64]^[65] Sanitation practices target the overwintering stage of E. necator, where chasmothecia form on infected debris and release ascospores in spring. Removing and destroying old canes, leaves, and fruit clusters at the end of the growing season—or through flail mowing and disking into the soil—breaks this cycle by limiting primary inoculum sources. Selecting grape varieties with partial resistance, such as certain Vitis hybrids or loose-clustered cultivars like Syrah, integrates sanitation with genetic tolerance, reducing overall debris infectivity. While intercropping or cover crops are sometimes used to improve soil health, their role in sanitation is indirect, primarily by enhancing biodiversity to dilute pathogen reservoirs.^[66]^[65]^[64] Timing of cultural interventions is critical to preempt E. necator outbreaks, particularly during the pre-flowering to fruit-set period when berries are most susceptible. Delayed or methodical winter pruning—spacing spurs appropriately and avoiding early cuts that expose wounds—minimizes premature ascospore release from overwintering structures. Post-budbreak, early shoot thinning aligns with rapid growth phases to prevent canopy closure, while nutrient adjustments (e.g., monitoring soil tests to limit excess vigor) are applied before bloom to curb lush foliage. Integrating these with disease forecasting models, such as temperature-based indices, allows precise timing, ensuring interventions coincide with high-risk windows without unnecessary disruption.^[66]^[64]^[67] Organic approaches complement cultural practices by providing preventive barriers, with sulfur dusting applied as a fine powder or wettable formulation during early shoot growth to inhibit spore germination on leaf surfaces. This method, effective at rates of 2-5 pounds per acre, leverages sulfur's disruptive effect on fungal metabolism and is often rotated with oils like stylet oil for broader coverage in certified organic systems. Monitoring tools, including phenology models that track degree-days and humidity thresholds, enable targeted applications, reducing overall input while maintaining efficacy. These strategies link to abiotic benefits by sustaining lower humidity levels in the canopy, as referenced in environmental factor discussions.^[63]^[64]^[67]

Fungicide and Biological Methods

Fungicides remain a cornerstone in managing Erysiphe necator, the causal agent of grapevine powdery mildew, with sulfur serving as a foundational non-systemic, multi-site protectant that exhibits no reported resistance due to its broad-spectrum mode of action (FRAC code M02).^[68] Sterol biosynthesis inhibitors, particularly demethylation inhibitors (DMIs; FRAC 3) such as myclobutanil, were widely adopted in the 1980s but have faced resistance since the early 1990s, with initial detections in California vineyards linked to mutations like Y136F that confer quantitative resistance.^[68] Similarly, quinone outside inhibitors (QoIs; FRAC 11), exemplified by azoxystrobin, and succinate dehydrogenase inhibitors (SDHIs; FRAC 7), such as boscalid, have encountered widespread resistance through mutations like G143A in QoIs and H242R in SDHIs, necessitating their integration into rotation programs to maintain efficacy.^[68] Biological control agents offer sustainable alternatives or complements to chemical fungicides, with Trichoderma species acting as mycoparasites that parasitize E. necator hyphae and induce plant defenses, achieving up to 70% disease reduction in integrated field trials when combined with sulfur.^[69] Bacillus subtilis strains similarly function through antagonism and volatile compound production, demonstrating comparable efficacy of up to 70% in multi-location trials against powdery mildew on grape leaves and clusters.^[69] Effective application of both fungicides and biological agents relies on timing aligned with the pathogen's life cycle, including protectant sprays initiated pre-bloom during early shoot growth to prevent ascospore germination and curative applications post-infection up to veraison, after which ontogenic resistance in berries reduces the need for intervention.^[49] Resistance management follows Fungicide Resistance Action Committee (FRAC) guidelines, emphasizing rotation among FRAC groups and limiting DMI use to no more than 50% of the seasonal spray program to curb selection pressure.^[70]^[71] Emerging strategies include spray-induced gene silencing (SIGS) via RNA interference, where double-stranded RNA targets essential E. necator genes like CYP51 to disrupt pathogen development; as of 2025, this remains in experimental stages with promising vineyard trials showing reduced disease severity comparable to conventional fungicides, though commercial deployment is pending regulatory approval.^[72]

Economic Importance and Research

Agricultural Impact

Uncinula necator, the causal agent of powdery mildew in grapevines, causes substantial yield reductions in untreated vineyards, ranging from 20% in moderate infections to up to 100% in severe cases under high disease pressure.^[73]^[74] These losses stem from reduced berry size, scarring, and premature defoliation, which collectively diminish cluster weight and overall production. The disease imposes significant economic burdens on global viticulture, with management costs alone exceeding $200 million annually in regions like California as of 2015, and broader impacts including yield shortfalls and quality degradation.^[75] In addition to quantitative impacts, the pathogen degrades grape quality by impairing berry development and composition, leading to reduced sugar accumulation in early infections and altered flavor profiles in resulting wines.^[76] Infected berries can exhibit off-flavors, with some studies reporting fungal odors that compromise wine aroma and sensory appeal.^[37] These quality defects can render harvests unsuitable for premium winemaking, further amplifying economic repercussions. The disease is particularly severe in key viticultural regions like California, Bordeaux, and Australia, where favorable climates promote rapid spread and require intensive management.^[77]^[78] Quarantine measures are implemented to prevent introductions of resistant strains or exacerbate existing pressures in these hotspots. Historically, 19th-century epidemics of U. necator, introduced to Europe around 1845, contributed to vineyard devastation and later compounded with the phylloxera crisis to reshape global viticulture.^[9] Management costs, including fungicide applications, add to the burden but are essential for mitigating these impacts as outlined in control strategies.^[68]

Ongoing Research Directions

Recent advances in molecular studies of Erysiphe necator (syn. Uncinula necator) have centered on genome sequencing efforts to uncover its genetic basis for host manipulation. A chromosome-scale genome assembly completed in 2023 spans 81.1 Mb and consists of 34 scaffolds (11 representing complete chromosomes), identifying 234 candidate secreted effector proteins that likely facilitate the pathogen's biotrophic lifestyle by suppressing host defenses.^[79] These effectors, enriched in duplicated gene regions, provide insights into how E. necator evades grapevine immunity, informing strategies for targeted resistance. Complementing this, CRISPR/Cas9 editing has been applied to grapevine genes such as VvMLO7 to engineer immunity against E. necator, with edited lines demonstrating reduced susceptibility in phenotypic assays conducted as recently as 2024.^[80]^[81] Research on fungicide resistance mechanisms has identified point mutations in the CYP51 gene as key contributors to demethylation inhibitor (DMI) insensitivity, particularly the Y136F substitution (A495T), which alters sterol biosynthesis and reduces azole binding efficacy.^[23] This mutation, often co-occurring with CYP51 overexpression, has been detected in field populations across multiple regions, driving the need for integrated management. Monitoring tools like quantitative real-time PCR (qPCR) assays enable rapid genotyping of these variants directly from infected samples, facilitating resistance surveillance and timely fungicide rotation.^[82]^[83] Climate change investigations model shifts in E. necator overwintering survival, predicting higher viability of mycelium in dormant buds under warmer winter scenarios, which could extend primary inoculum sources and intensify epidemics in temperate viticulture zones.^[84] Adaptive genomic variations, including structural changes in repetitive regions, suggest evolving pathogen populations may enhance resilience to fluctuating environmental stresses.^[85] Addressing knowledge gaps, current studies emphasize incomplete understanding of microbiome interactions, where grapevine phyllosphere bacteria and mycoparasites like Ampelomyces quisqualis could modulate E. necator colonization, though functional mechanisms remain underexplored.^[61] Sustainable integrated pest management (IPM) and novel biopesticides, such as RNA-based interventions and biofungicide formulations, are under field trials in 2024–2025 to reduce reliance on synthetics amid rising resistance pressures.^[86]^[87] These efforts tie to ongoing economic losses from powdery mildew in grape production, with significant annual costs in major viticultural regions.^[75]

References

[1]
Erysiphe necator | Viticulture and Enology - UC Davis
Superficially, the fungus creates white, powdery like spots on the top side of the leaves, and on the berries. Erysiphe necatoralso has reddish-black resting ...<|control11|><|separator|>
[2]
Grape Powdery Mildew | New Mexico State University
Powdery mildew disease, caused by the fungus Erysiphe necator (formerly Uncinula necator), afflicts grape-growing regions worldwide, including New Mexico.
[3]
Powdery Mildew of Grape - Ohioline
Apr 15, 2016 · The powdery mildew fungus can infect all green tissues of the vine. Small, white or grayish-white patches of fungal growth appear on the upper ...
[4]
Erysiphe necator (UNCINE)[Overview] - EPPO Global Database
Phylum Ascomycota ( 1ASCOP ) ; Subphylum Pezizomycotina ( 1PEZIQ ) ; Class Leotiomycetes ( 1LETOC ) ; Order Erysiphales ( 1ERYSO ) ; Family Erysiphaceae ( 1ERYSF ).
[5]
[PDF] Phylogeny of Erysiphe, Microsphaera, Uncinula - Zobodat
Erysiphe (Microsphaera) alphitoides, Erysiphe ( Uncinula) necator, etc. ... 1998: Phylogenetic analysis and predicted secondary structures of the rDNA ...
[6]
Phylogeography and population structure of the grape powdery ...
Sep 1, 2010 · Genetic diversity in eastern US and introduced populations. We obtained 146 isolates of E. necator from diverse wild and cultivated Vitis ...Missing: fossil | Show results with:fossil
[7]
Grapevine powdery mildew (Erysiphe necator) - PubMed Central - NIH
Jun 20, 2011 · Shoots arising from these buds may be heavily coated with fungal growth, stark white in colour and stand out like white flags in the vine, ...
[8]
Names Record - Index Fungorum
Record Details: Erysiphe necator Schwein., Trans. Am. phil. Soc., New Series 4(2): 270 (1832) [1834]. Typification Details: Typification: Schweinitz 2495
[9]
Erysiphe necator (grapevine powdery mildew) | CABI Compendium
Mar 28, 2022 · This datasheet on Erysiphe necator covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Natural Enemies, ...
[10]
One stop shop IV: taxonomic update with molecular phylogeny for ...
Sep 24, 2020 · This is a continuation of a series focused on providing a stable platform for the taxonomy of phytopathogenic fungi and fungus-like organisms.
[11]
The Perfect Stage of Powdery Mildew of Grapevine Caused by ...
Apr 10, 2012 · Grapevine powdery mildew caused by Erysiphe necator (Schwein.) (formerly Uncinula necator [Schw.] Burr.; anamorph Oidium tuckeri) is currently ...Missing: synonyms | Show results with:synonyms
[12]
The Amsterdam Declaration on Fungal Nomenclature - IMA Fungus
Jun 7, 2011 · The Amsterdam Declaration on Fungal Nomenclature was agreed at an international symposium convened in Amsterdam on 19–20 April 2011.Missing: Uncinula necator
[13]
The impacts of the discontinuation of dual nomenclature of ...
Jun 21, 2012 · All anamorph-typified genera are younger than the corresponding teleomorph-typified genera (except for Oidium) and hence will be younger ...
[14]
https://doi.org/10.1094/PHYTO-97-10-1356
[15]
[PDF] investigations in asexual development in erysiphe ecator ...
Following inoculation, Erysiphe colonies grow in a purely vegetative state for a period of 5-9 days.
[16]
Linkage Disequilibrium and Spatial Aggregation of Genotypes in ...
The LD observed in these populations is most likely the result of asexual reproduction; E. necator typically has ≥10 asexual generations per year. Clones ...
[17]
Dynamics of ascospore maturation and discharge in Erysiphe ...
Uncinula necator), the causal agent of powdery mildew of grape (Vitis vinifera L.), is a heterothallic fungus (3,42,44). Once initiated, the chasmothecia mature ...
[18]
Uncinula necator - cleistothecium with uncinate (hooked) appendages
Uncinula necator - cleistothecium with uncinate (hooked) appendages. Files: Uncinula_necator_cleistothecium_with_uncinate_hooked_appendages.jpg (286.21 KB)
[19]
(PDF) Initiation and development of Erysiphe necator chasmothecia ...
Aug 6, 2025 · Microscopic examination showed that chasmothecia contained 1–5 (usually three) asci with 1–4 (usually three) ascospores in each asci, and 65.6% ...
[20]
Occurrence of Erysiphe necator Chasmothecia and Their Natural ...
5. Development of chasmothecia of Erysiphe necator on leaves in an untreated vineyard in S. ... were 11.5 to 14.5 µm in length (major axis) and 2.5 to 3.5 µm in.
[21]
A model for the development of Erysiphe necator chasmothecia in ...
Sep 20, 2013 · Preventing infections caused by ascospores in one season requires treatments that prevent formation or maturation of chasmothecia during the ...
[22]
Release of Erysiphe necator Ascospores and Impact of Early ...
Aug 1, 2014 · Burr (syn. Uncinula necator), threatens the sustainable production of grapes in vineyards irrespective of climate or locale (Pearson 1988).Missing: reclassified | Show results with:reclassified
[23]
Comprehensive analyses of the occurrence of a fungicide resistance ...
Sep 13, 2023 · Comprehensive analyses of the occurrence of a fungicide resistance marker and the genetic structure in Erysiphe necator populations.Missing: generations | Show results with:generations
[24]
[PDF] ms 2741 Sawant.indd
Sexual reproduction provides more chances of genetic recombination which results in development of new strains with attributes like enhanced fungicide ...<|control11|><|separator|>
[25]
Variation in Pathogenicity and Aggressiveness of Erysiphe necator ...
Brewer, M. T., and Milgroom, M. G. 2010. Phylogeography and population structure of the grape powdery mildew fungus Erysiphe necator from diverse Vitis species.Missing: Muller | Show results with:Muller
[26]
Mechanisms of powdery mildew resistance in the Vitaceae family
Vitis vinifera is highly susceptible to the powdery mildew pathogen Erysiphe necator. However, other species within the Vitaceae family have been reported to ...
[27]
Phenotyping for QTL identification: A case study of resistance to ...
Vitis vinifera is the most widely cultivated grapevine species. It is highly susceptible to Plasmopara viticola and Erysiphe necator.
[28]
RUN1 and REN1 Pyramiding in Grapevine (Vitis vinifera cv ...
May 11, 2017 · Our results reveal that RUN1REN1 grapevine plants display a robust defense response against E. necator, leading to unsuccessful fungal establishment.
[29]
Vitis rupestris B38 Confers Isolate-Specific Quantitative Resistance ...
Aug 10, 2015 · Vitis rupestris B38 is a North American grapevine resistant to the major pathogen of cultivated grapevines, Erysiphe necator.
[30]
Phylogeography and population structure of the grape powdery ...
Sep 1, 2010 · The grape powdery mildew fungus, Erysiphe necator, was introduced into Europe more than 160 years ago and is now distributed everywhere that ...
[31]
Powdery Mildew / Grape / Agriculture - UC IPM
Initial symptoms of powdery mildew appear on leaves as chlorotic spots on the upper leaf surface. Signs of the pathogen appear a short time later as white, ...Missing: Uncinula pathological
[32]
[PDF] Grapevine Powdery Mildew - Cornell eCommons
The PM fungus can infect all green tissues of the grapevine. On leaves, it appears as a white or grayish-white powdery covering of the upper and lower surfaces ...
[33]
[PDF] Powdery mildew of grapes - GRAPEVINE DISEASES - Virginia Tech
Symptoms and signs: All succulent green tissues of the vine are susceptible to infection at some time in their development. The fungus penetrates only the ...
[34]
[PDF] Pest Control in Grapes, PPP-102
Copper can damage the leaves and fruit of sensitive varieties. Sulfur. Target disease: powdery mildew. Acres treated: less than 20% of total acres1. Rate and ...
[35]
Effects of Bunch Rot (Botrytis cinerea) and Powdery Mildew ... - NIH
Mar 28, 2017 · Both fungi can affect grape berries, resulting in yield losses and reduced fruit quality depending on the degree of infection (Stummer et al., ...
[36]
Current understanding of grapevine defense mechanisms against ...
May 20, 2015 · The existence of major R-gene resistance against E. necator in Vitis species native to China and Central Asia brings into question the current ...
[37]
Grapevine powdery mildew (Erysiphe necator): a fascinating system ...
Jun 20, 2011 · Grapevine powdery mildew (Erysiphe necator): a fascinating system for the study of the biology, ecology and epidemiology of an obligate biotroph.Morphology And Reproductive... · Pathogen Biology And Ecology · Host ResistanceMissing: Muller | Show results with:Muller<|separator|>
[38]
Uncinula Necator - an overview | ScienceDirect Topics
Uncinula necator is defined as a fungus responsible for powdery mildew, a significant disease affecting grape yields, juice, and wine quality in vineyards. AI ...
[39]
Effects of wind, relative humidity, leaf movement and colony age on ...
Aug 15, 2007 · ... dispersal of conidia of Uncinula necator. Wind speed as low as 2.3 m ... On average, 0.3–0.5 conidia were dispersed per conidium available for ...Missing: distance | Show results with:distance
[40]
Effects of wind, relative humidity, leaf movement and colony age on ...
Aug 6, 2025 · Greater wind speeds could lead to longer dispersal distances as reported for Uncinula necator in grapes in a wind tunnel experiment (Willocquet ...
[41]
Genetic Variation and Population Structure of the Grape Powdery ...
Erysiphe necator, the causative agent of powdery mildew in grapevine, was introduced into Europe from North America during the middle of the 19th century.
[42]
Population structure of Erysiphe necator on domesticated and wild ...
Jan 18, 2021 · Erysiphe necator ... Délye, C., and Corio-Costet, M.F. (1998) Origin of primary infections of grape by Uncinula necator: RAPD analysis ...
[43]
Environmental Relationships in the Powdery Mildews - ResearchGate
Aug 10, 2025 · Clesitothecia of Uncinula necator (Schw.) Burr were once widely believed to be relatively an important in the epidemiology of grape powdery ...
[44]
[PDF] Powdery Mildew of Grapes - PLANT DISEASE
The presence of mycelia with conidiophores and conidia on the surface of the host tissue gives it a whitish gray, dusty or powdery appearance. Both surfaces of.Missing: shape | Show results with:shape<|control11|><|separator|>
[45]
The influence of temperature during the development of conidia on ...
Optimum temperature for conidial germination is 24-25 °C (Doster and Schnathorst, 1985a; Fessler and Kassemeyer, 1995; Willocquet et al., 1996) and fungal ...
[46]
Effect of weather factors on the release of ascospores of Uncinula ...
Aug 7, 2025 · The release periods of ascospores were always associated with a rainfall higher than 2 mm, a wetting duration greater than 2.5 h, an average ...
[47]
[PDF] Integrated Pest Management for Powdery Mildew of Grapes in Arizona
Jan 1, 2025 · Upon a successful infection, the fungus will spread out on the plant's surface in the form of hyphal colonies (the white/ silver fuzz most often ...
[48]
Effects of radiation, especially ultraviolet B, on conidial germination ...
Conidia ofUncinula necator inoculated on vine leaf disks were exposed to different irradiation conditions during various combinations of irradiation period.
[49]
Climate change impacts on plant pathogens, food security and paths ...
May 2, 2023 · Climate change will expectedly increase plant diseases in crops. ... Similarly, for many diseases (for example, powdery mildews of grapevine ...
[50]
Climate vs grapevine pests and diseases worldwide - OENO One
Powdery mildew was reported #1 pest in a larger range of temperature conditions (15.1 to 21.8°C) with globally lower rainfall during the grape growing season ( ...Abstract · Introduction · Material and methods · Results and discussion
[51]
No Indication of Strict Host Associations in a Widespread Mycoparasite
Jun 5, 2012 · Some strains have already been developed as commercial biocontrol agents (BCAs) of Erysiphe necator and other powdery mildew species infecting ...
[52]
Fungi Parasitizing Powdery Mildew Fungi: Ampelomyces Strains as ...
In the interaction between Ampelomyces strains and PM fungi, the spores of the mycoparasites germinate on plant leaves, and their hyphae then penetrate the ...Fungi Parasitizing Powdery... · 4. Ampelomyces As An... · 6. Ampelomyces Strains May...
[53]
Biological Control of Grape Powdery Mildew Using Mycophagous ...
Uncinula necator (syn. Erysiphe neca- tor), the causal agent of grape powdery mildew, is the most destructive pathogen of grapes worldwide, including the ...
[54]
Minimal Pruning and Reduced Plant Protection Promote Predatory ...
Aug 18, 2017 · These predatory mites are generalists that can sustain stable populations even when prey numbers are low by surviving and reproducing on ...Missing: antagonists | Show results with:antagonists
[55]
Effects of Bunch Rot (Botrytis cinerea) and Powdery Mildew ...
Mar 27, 2017 · This study focused on Botrytis cinerea and Erysiphe necator, since they are amongst the most relevant fungi in viticulture and have a world ...Missing: synergists co-
[56]
The role of arbuscular mycorrhizal fungi in abiotic stress ...
Arbuscular mycorrhizal fungi (AMF) have been shown to enhance grapevine resilience to abiotic stresses, which are becoming increasingly severe due to climate ...
[57]
Powdery Mildew Resistance Genes in Vines - PubMed Central
Jun 18, 2022 · Two main gene families confer resistance to powdery mildew in the Vitaceae, Run (Resistance to Uncinula necator) and Ren (Resistance to Erysiphe necator).
[58]
Grapevine Phyllosphere Community Analysis in Response to Elicitor ...
Powdery mildew is a ubiquitous disease, and its causal agent, Erysiphe necator (syn. Uncinula necator), is a polycyclic fungus able to infect all the plant ...
[59]
A Comparative Analysis of Microbe-Based Technologies Developed ...
Globally, Erysiphe necator causing powdery mildew disease in grapevines (Vitis vinifera L.) is the second most important endemic disease, causing huge economic ...
[60]
Revealing microbial consortia that interfere with grapevine downy ...
Mar 27, 2025 · Surprisingly, the soil microbiota was a better predictor of disease incidence and severity than the leaf microbiota, suggesting that the soil ...
[61]
Powdery Mildew of Grapes | UA Cooperative Extension
The disease was first described in North America (where it is believed to have evolved with North American Vitis species) in the early 19th century and was ...
[62]
A Spring IPM Toolbox for Controlling Powdery Mildew in Vineyards
Apr 22, 2021 · The Spring vineyard IPM toolbox is full of preventative, cultural, and chemical methods that will help you control powdery mildew in your vineyard.
[63]
Powdery mildew - The Australian Wine Research Institute
Powdery mildew is the common term for a group of plant diseases. In grapevines the disease is caused by the fungus originally named Uncinula necator.
[64]
Powdery mildew (Uncinula necator) – eVineyard blog
Aug 31, 2015 · Powdery mildew, among winegrowers more known as Oidium, is caused by the fungus Uncinula necator. The disease originates from North America but is now widely ...
[65]
[PDF] Basic Training for Combating Mildew - Washington Wine Commission
Growers use a variety of tactics and tools to control powdery mildew, from cultural practices that increase sunlight exposure to leaves and fruit and encourage ...
[66]
Grapevine Powdery Mildew: Fungicides for Its Management and ...
Jul 20, 2021 · In this review, we describe major fungicide classes used for grapevine powdery mildew management and the most common single nucleotide mutations in target ...
[67]
A Comparative Analysis of Microbe-Based Technologies Developed ...
In the recent past, several biological control agents of microbial origin have been evaluated and used to control the powdery mildew pathogen in grapes. Among ...
[68]
https://pmc.ncbi.nlm.nih.gov/articles/PMC8307186/
[69]
Fungicide Resistance Management / Grape / Agriculture - UC IPM
Select a FRAC group, rotate groups each application, and use each group only once per season, except for multi-site or natural products.
[70]
Spray-induced Silencing of Grape Powdery Mildew Genes to ...
Apr 4, 2025 · The technology is called Spray Induced Gene Silencing (SIGS) and uses double-stranded (ds)RNA designed to specifically target powdery mildew genes required for ...Missing: Uncinula | Show results with:Uncinula
[71]
Disease Forecasting for the Rational Management of Grapevine ...
If not controlled, they can cause yield losses of up to 75–100% during a high disease-pressure year [2,3,4], and reduce wine quality [5,6,7].<|control11|><|separator|>
[72]
Effects of Uncinula necator on the yield and quality of grapes (Vitis ...
Jul 1, 2004 · Powdery mildew (Uncinula necator) is the most widespread and destructive disease of grapevines worldwide, and is the main target of fungicides ...<|separator|>
[73]
Advances in the molecular mechanism of grapevine resistance to ...
Jan 2, 2025 · Effectors either promote fungal virulence by suppressing the host immune reaction or triggering HR (Lo Presti et al. 2015). At present, research ...
[74]
[PDF] Grape Powdery Mildew - Gov.bc.ca
Provides protective, eradicant and antisporulant effects against grape powdery mildew. Do not apply in a spray volume of less than 1000 L water/ha (1 ...Missing: Duhamel 2002
[75]
Powdery Mildew in California Grapes - Center for Wine Economics
Nov 14, 2023 · Grape powdery mildew (Erisiphe necator, syn. Uncinula necator) is the most significant disease in terms of expenses for control and losses in quality and yield.
[76]
Managing Powdery Mildew | Wine Australia
Powdery mildew is managed with chemical fungicide sprays, often 6-7 times per season, and by timing sprays appropriately.Missing: California Bordeaux quarantine
[77]
(PDF) Major Outbreaks in the Nineteenth Century Shaped Grape ...
Nov 8, 2019 · During the 19th century, the accidental introduction of powdery mildew (Uncinula necator) [2] into Europe ~1845 from exported North American ...
[78]
A chromosome-scale genome assembly of the grape powdery ... - NIH
Jun 21, 2023 · Sterol composition of the Vine powdery mildew fungus, Uncinula necator: comparison of triadimenol-sensitive and resistant strains.
[79]
CRISPR/Cas9-mediated mutagenesis of VvMLO3 results in ... - Nature
Aug 1, 2020 · This demonstrates that CRISPR/Cas9-targeted mutagenesis can be used to develop disease-resistant cultivars and facilitate the functional ...
[80]
CRISPR/Cas9‐driven double modification of grapevine MLO6‐7 ...
Dec 8, 2024 · The characterization of three edited lines for each target demonstrated immunity development against Erysiphe necator in MLO6-7-edited plants.
[81]
Assessment of fungicide resistance and pathogen diversity in ...
Oct 14, 2010 · The aim of the present study was to develop real-time qPCR tools to detect and quantify several CYP51 gene variants of E. necator: (i) A versus ...
[82]
Improved DNA extraction and quantitative real-time PCR for ...
Mar 14, 2020 · Improved DNA extraction and quantitative real-time PCR for genotyping Erysiphe necator and detecting the DMI fungicide resistance marker A495T, ...Missing: qPCR | Show results with:qPCR
[83]
Modelling the impact of climate change on the interaction between ...
Feb 15, 2012 · This would imply an increase in the number of reproductive events per year, leading to an increase in population, and increased levels of ...
[84]
Adaptive genomic structural variation in the grape powdery mildew ...
Dec 9, 2014 · This disease is caused by the fungus Erysiphe necator Schw. [syn. Uncinula necator (Schw.) Burr.], an obligate biotroph that can infect all ...Missing: reclassified | Show results with:reclassified
[85]
GreenLight Biosciences Submits Regulatory Dossier in US, EU and ...
a groundbreaking first in agricultural disease management.
[86]
[PDF] Field evaluation of bio-fungicides to control powdery mildew ...
Four field trials were conducted across two seasons (2023–2024) at Fresno site in the San Joaquin. Valley and San Luis Obispo site in ...
[87]
[PDF] optimizing biofungicide use in managing winegrape powdery
Grapevine powdery mildew caused by the fungal pathogen Erysiphe necator is a persistent threat to wine grape production in California. While synthetic ...<|control11|><|separator|>