Advances in viticultural management techniques have become increasingly important for mitigating the effects of challenging climatic conditions. The double-pruning technique is already widely used in Brazilian vineyards, enabling a shift of the harvest season from summer to winter. This shift allows key phenological stages, such as flowering, ripening, and harvest, to occur under milder temperatures and reduced precipitation. In contrast, the use of plastic coverings allows growers to maintain the conventional grapevine cycle while providing a physical barrier that protects the plants. Although both techniques are known and applied in some regions of the country, little information is available on their combined effects, particularly regarding plant physiology. Considering this gap, the present study evaluated the combined effects of double pruning and plastic coverings on the internal and external morphology and physiology of cv. Sauvignon blanc grapevines. The plastic covering prevented the direct incidence of rainwater on leaves and reduced the wash-off of applied fungicides. This led to lower disease incidence and fewer pesticide applications. Additionally, plastic covering reduced the photosynthetic photon flux density (PPFD) to levels close to the light saturation point of the grapevine, while also altering the light spectrum by attenuating UV-B radiation (280–315 nm). Together, these factors enhanced key physiological processes, including photosynthesis, transpiration, stomatal conductance, and chlorophyll accumulation. Leaf area is high in covered plants, and anatomical analyses revealed plastic responses in uncovered vines to excess light and UV-B exposure, such as thicker epidermal and palisade tissues and the deposition of epicuticular wax around stomata. However, these structural adjustments did not result in greater CO2 assimilation. Overall, this study demonstrates that the combination of simple management practices, as plastic covering, can improve and facilitate grapevine cultivation under challenging weather conditions, while also providing valuable insights into the physiological responses of the plant.

A lichia é uma fruta muito apreciada no mundo. No Brasil, seu cultivo é recente e o Estado de São Paulo é um dos principais produtores dessa fruta, por haver condições climáticas ideais para sua exploração. Esse boletim técnico traz todas as informações necessárias para a exploração racional e econômica da lichieira. Esta obra faz parte da "Série Produtor Rural", editada desde 1997 pela Divisão de Biblioteca da Escola Superior de Agricultura "Luiz de Queiroz"/USP e tem como objetivo publicar textos acessíveis aos produtores com temas diversificados e informações práticas, contribuindo para a Extensão Rural.

Chemical control is among the most widely used strategies in plant disease management and remains essential in many agricultural pathosystems. Understanding the dynamics of fungicide absorption and translocation within plants is therefore critical for optimising control strategies. This study aimed to evaluate the foliar absorption and translocation of three systemic fungicides, epoxiconazole, pyraclostrobin, and fluxapyroxad, in grapevines. Commercial formulations containing (14C)-labelled molecules were used. Applications were performed with a micro-applicator on specific grapevine leaves, and absorption and translocation were quantified at five-time intervals (3, 9, 24, 48, and 72 hours after application) using liquid scintillation spectrometry and autoradiography. The results indicate that fluxapyroxad exhibited the lowest absorption throughout the evaluation period. After 72 hours, 64 % of the fluxapyroxad remained on the grapevine-treated leaf, which was twice the amount observed for epoxiconazole and pyraclostrobin. Therefore, in grapevine leaves, the majority of the absorbed products of all three systemic fungicides remained at the site of application, when intertissue mobility was low, below 0.2 %, with reduced but detectable systemic translocation. These findings contribute to a better understanding of the dynamics of the absorption and translocation of these compounds in grapevines, providing a basis for the development of more effective plant disease management strategies.

Grapevine plants showing symptoms typically induced by phytoplasmas infection, characterized by leaf reddening or yellowing, reduce vigour, delayed growth and shoot proliferation with reduced leaf size, were observed in the state of São Paulo, Brazil. This disorder causes significant damage to grape production by delaying the onset of fruit bearing and reducing yield. Similar symptoms have been reported in grapevines grown in other countries revealing the presence of phytoplasmas in diseased plants. Based on the described symptoms, this study was conducted in order to demonstrate the association between phytoplasma and symptomatic grapevine plants, as well as characterize molecularly the detected pathogen. Molecular analysis was performed using PCR and RFLP assays, followed by phylogenetic analysis. Amplifications of genomic fragments of 1.2 evidenced the presence of phytoplasma in tissue of symptomatic samples confirming the preliminary diagnosis based on the symptoms. Molecular characterisation identified the phytoplasma as a ‘ Ca Phytoplasma prunorum’ strain, belonging to the 16SrX-B subgroup. This is the first report of a phytoplasma belonging to the 16SrX-B group infecting grapevine plants in Brazil.

Drought reduces host resistance and allows the emergence of pathogens that benefit from changes in plant physiology under water stress. However, for pathogens that penetrate only via the stomata, like Aculeastrum americanum, stomatal closure due to water stress can prevent infection. Here, we test the hypothesis that raspberry (Rubus idaeus) late leaf rust severity is intensified when water deficit is imposed after penetration of A. americanum in leaves. We perform epidemiological and quantitative analyses of A. americanum colonisation, as well as measurements of leaf gas exchange, on healthy and inoculated leaves of R. idaeus 'Heritage'. Plants were either grown under well-watered conditions throughout the experimental period (control) or submitted to water withholding 2 days after inoculation (water deficit). Our results revealed that the incubation and latent periods, urediniospore production and lesion density did not differ between the two water regimes. However, water deficit significantly reduced rust severity, A. americanum colonisation and leaf gas exchange in both healthy and inoculated plants. Comparing the biotic and abiotic stresses, late leaf rust has a greater impact on leaf CO2 assimilation than water deficit. In addition, there was a synergism between leaf rust and water deficit, causing further decreases in leaf gas exchange of raspberry plants. Based on these findings, we conclude that the occurrence of water deficit after the onset of pathogen infection reduces rust severity by limiting its colonisation capacity, a consequence of low photoassimilate supply to the pathogen due to impaired photosynthetic activity.

Genomic selection (GS) is becoming increasingly widespread and applied due to the promising results obtained, cost savings in generating single nucleotide polymorphism (SNP) markers, and the development of statistical models that allow to improve the analysis robustness and accuracy. GS might shorten the selection cycle, which has a major impact, especially for perennial species. The composition and size of the training population have a major influence on GS, which poses challenges for interspecific biparental populations. Another factor is the use of different reference genomes from other species to perform SNP calling, which could make it possible to explore variability in interspecific crosses comprehensively. Late leaf rust is a disease caused by the pathogen Acculeastrum americanum , and the rare reports on genetic resistance to this pathogen are related to the species Rubus occidentalis , which leads to the need for interspecific hybridizations, aiming to combine the fruit quality of R. idaeus with the resistance of R. occidentalis . Given the above, we evaluated the effect of different reference genomes on the SNP markers discovery, as well as training population optimization (TPO) strategies on the accuracy of genomic predictions, namely the CV-α, leaving-one-family-out (LOFO), pairwise families, and stratified k-fold. The composition of the training set in a stratified manner, together with a matrix of markers combined with the reference genomes, increased the model's predictive capacity. These results corroborate that genomic prediction aligned with SNP calling and training population optimization strategies can significantly increase genetic gains in interspecific biparental crosses.

Over the last 10 years, global raspberry production has increased by 47.89%, based mainly on the red raspberry species (Rubus idaeus). However, the black raspberry (Rubus occidentalis), although less consumed, is resistant to one of the most important diseases for the crop, the late leaf rust caused by Acculeastrum americanum fungus. In this context, genetic resistance is the most sustainable way to control the disease, mainly because there are no registered fungicides for late leaf rust in Brazil. Therefore, the aim was to understand the genetic architecture that controls resistance to late leaf rust in raspberries. For that, we used an interspecific multiparental population using the species mentioned above as parents, 2 different statistical approaches to associate the phenotypes with markers [GWAS (genome-wide association studies) and copula graphical models], and 2 phenotyping methodologies from the first to the 17th day after inoculation (high-throughput phenotyping with a multispectral camera and traditional phenotyping by disease severity scores). Our findings indicate that a locus of higher effect, at position 13.3 Mb on chromosome 5, possibly controls late leaf rust resistance, as both GWAS and the network suggested the same marker. Of the 12 genes flanking its region, 4 were possible receptors, 3 were likely defense executors, 1 gene was likely part of signaling cascades, and 4 were classified as nondefense related. Although the network and GWAS indicated the same higher effect genomic region, the network identified other different candidate regions, potentially complementing the genetic control comprehension.

Raspberries (Rubus spp) are temperate climate fruits with profitable high returns and have the potential for diversification of fruit growing in mid to low-latitude regions. However, there are still no cultivars adapted to climatic conditions and high pressure of diseases that occurs in tropical areas. In this context, our objective was to evaluate the genetic diversity from a 116 raspberry genotypes panel obtained from interspecific crosses in a testcross scheme with four cultivars already introduced in Brazil. The panel was genotyped via genotyping-by-sequencing. 28,373 and 27,281 SNPs were obtained, using the species R. occidentalis and R. idaeus genomes as references, respectively. A third marker dataset was constructed consisting of 41,292 non-coincident markers. Overall, there were no differences in the results when using the different marker sets for the subsequent analyses. The mean heterozygosity was 0.54. The average effective population size was 174, indicating great genetic variability. The other analyses revealed that the half-sibling families were structured in three groups. It is concluded that the studied panel has great potential for breeding and further genetic studies. Moreover, only one of the three marker matrices is sufficient for diversity studies.

Late leaf rust is a fungal disease in raspberries caused by Aculeastrum americanum (Farl.) M. Scholler U. Braun (syn. Thekopsora americana (Farl.) Aime McTaggart) leading to early defoliation and yield losses. Red raspberries (Rubus idaeus L.) are susceptible to this pathogen, although this susceptibility varies among cultivars. In contrast, black raspberries were previously reported to be more resistant (Rubus occidentalis L.) and immune (Rubus niveus Thunb.) to this pathogen, raising their importance in plant breeding programs. However, what features make them respond differently to the same pathogen? In this study, we characterize for the first time the pre- and post-formed structural and biochemical defense mechanisms of R. idaeus cv. Autumn Bliss, R. occidentalis and R. niveus. Ultrastructural and histopathological analyses were used to uncover the interactions between these raspberries and A. americanum. The ultrastructural results indicate that the pathogen germinates on both leaf surfaces but can only form appressoria on the stomata. Although the three raspberry species were infected and colonized by A. americanum, a clear difference in susceptibility was observed between them. A compact mesophyll, pre- and post-formed phenolic compounds, and post-formed pectic compounds were the main plant defense mechanisms against fungal colonization. These findings provide new information about raspberries’ defense mechanisms in response to A. americanum and elucidate the interactions occurring in these pathosystems.

Late leaf rust (Thekopsora americana) is a disease that affects raspberry (Rubus idaeus L.), leading to a decrease in raspberry production. The adoption of precise criteria for disease quantification helps decision-making for its management. A diagrammatic scale (DS) is a useful tool for quantifying disease severity in the field. A DS was developed and validated in this study to estimate late leaf rust severity in raspberry leaves. The DS was defined with eight levels of severity (0.2, 0.4, 0.9, 2.2, 5.1, 11.5, 23.9 and 43.2%). The validation was performed by 15 untrained raters in two steps, with and without using the DS. Two approaches were used for statistical analysis: linear regression and Lin's method. Both analyses demonstrated that the use of the DS improved the precision and accuracy of the disease estimates. The inter-rater reliability was estimated by the coefficient of determination (R-2) and the intra-class correlation coefficient (ICC). Again, the use of the DS improved the reproducibility of the estimates. For the first time, a diagrammatic scale was developed and validated to evaluate late leaf rust severity in raspberry leaves.

Guava producers in Brazil have reported the occurrence of small, pink spot lesions on the surface of fruits in orchards. Symptomatic fruits were harvested from commercial guava orchards, and 18 monosporic isolates were obtained. All tested isolates were pathogenic to guava fruit and showed colony and conidial characteristics indicative of cercosporoid fungi. Phylogenetic analysis of the concatenated gene sequences showed that all isolates belonged to the genus Cercospora and clustered into four haplotypes. Conidia released 3-5 germ tubes, and penetration occurred through the stomata. All isolates produced cercosporin. Histopathological analyses showed that hyphal growth occurred intercellularly and that there was a collapse of epidermal and subepidermal cells in the injured areas. In addition, the oil cavities in the lesioned tissue had large numbers of lipid droplets compared with the nonlesioned tissue. This is the first report of Cercospora spp. as the causal agent of pink spot disease of guava fruit in Brazil.

Abiotic stress is increasingly common in agricultural areas due to climate change. The main leaf disease of raspberry plants (Rubus ideaus) in Brazil is late leaf rust (Thekopsora americana). The association between abiotic and biotic stress can lead to different plant responses relative to that observed with only one type of stress. To determine the interference of abiotic stress caused by water limitation on the intensity of late leaf rust in raspberries, the epidemiological disease parameters, gas exchange and plant growth of inoculated and noninoculated plants under controlled water management were evaluated. Plants under water deficit showed reduced growth in the aerial part, a lower intensity of late leaf rust and a reduction of related gas exchange parameters. Plants without water stress showed a reduced photosynthetic rate related to increased disease severity. Synergism was not observed between biotic and abiotic stresses for late leaf rust in raspberries.

Citrus Black Spot (CBS), caused by the ascomycete, Phyllosticta citricarpa, is a fruit, foliar, and twig spotting fungal disease affecting the majority of commercial cultivars of citrus. The disease causes cosmetic lesions, may cause fruit drop and P. citricarpa is considered a quarantine pathogen by some countries, impacting domestic and international trade of citrus fruit. Regulatory requirements affecting fruit trade exist even though there is no documented case of disease spread via infected fruit into previously disease-free areas. To clarify the risk of fruit as a potential pathway for the spread of CBS, we developed a quantitative, probabilistic risk assessment model. The model provides an assessment of all steps in the fruit pathway, including production, packinghouse handling, transportation, export-import distribution channels, and consumer endpoints. The model is stochastic and uses Monte Carlo simulation to assess the risk of P. citricarpa moving through all steps in the pathway. We attempted to use all available literature and information to quantitate risk at each point in the potential pathway and by sequentially linking all steps to determine the overall quantitative risk. In addition, we assessed climatological effects on incidence of diseased fruit at production sites and on fungal reproduction and infection, as well as criteria for establishment at endpoints. We examined ten case studies between exporting and importing locations/countries. Model results indicated fruit to be an epidemiologically insignificant means for CBS spread, even between producing countries where CBS occurs and CBS-free importing countries with disease-conducive climates. We created a second model to examine the introduction of infected plant material from countries where CBS occurs. This model demonstrated significant probability of introduction via such infected material. However, pathogen establishment and disease development was still restricted only to areas with conducive climatological conditions. We created a tool to quantitatively explore the viability of various potential pathways via combinations of CBS-present production sites and corresponding pathway endpoints, including environments conducive and non-conducive to CBS. The tool is provided to aid decision makers on phytosanitary risk relative to international trade of citrus fruit.

The trellis system used in grapevine cultivation greatly influences yield due to leaf surface exposure to solar radiation, which implies that physiological responses are involved in fruit production and quality. The American table grape cv. Niagara Rosada (Vitis labrusca) was first planted in Brazil using the vertically shoot-positioned (VSP) system. However, in areas where cv. Niagara Rosada replaced European table grapes (Vitis vinifera), growers usually use the existing overhead trellis system. This study evaluated the physiology and production of cv. Niagara Rosada grapevines grown on the overhead trellis system and VSP system. The trellis system had no influence on the duration in total days from the pruning-to-harvest period or on the absolute growth rate of shoots. The leaf area index and leaf surface area were higher on overhead trellis systems than on the VSP system. Fruit growth was similar regardless of the system adopted. Grapevines in the VSP system produced fruits with higher concentrations of soluble solids and anthocyanins than those in the overhead trellis system. Grapevines on the overhead trellis system present a better ratio between leaf surface area and production, as well as higher yields. However, grapevines grown on the VSP system have fruit with better qualities.

A worldwide survey of cercosporoid ascomycete species on hosts of the genus Diospyros (persimmon) with key to the species based on characters in vivo is provided. Special emphasis is placed on species of the genus Pseudocercospora, which are in part also phylogenetically analysed, using a multilocus approach. Species of the latter genus proved to be very diverse, with a remarkable degree of cryptic speciation. Seven new species are described (Pseudocercospora diospyri-japonicae, P. diospyriphila, P. ershadii, P. kakiicola, P. kobayashiana, and P. tesselata), and two new names are introduced [P. kakiigena (≡ Cylindrosporium kaki, non Pseudocercospora kaki), and Zasmidium diospyri-hispidae (≡ Passalora diospyri, non Zasmidium diospyri)]. Six taxa are lectotypified (Cercospora atra, C. diospyri, C. diospyri var. ferruginea, C. flexuosa, C. fuliginosa, C. kaki), and Pseudocercospora kaki is epitypified.

Cercosporiosis, caused by Pseudocercospora kaki, is the major foliar disease in persimmon crops. Despite the importance of the disease, we have little information about the interaction of this pathogen with persimmon leaf tissues. Therefore, to elucidate the infection and colonization process in these pathosystem, we investigated this interaction using light and scanning electron microscopy. Forty-eight hours after inoculation, the germ tubes produced from conidia and entered the leaf tissue only through the stomata. The lesions formed were limited to the areolas of leaf venation. The accumulation of phenolic and lipophilic compounds, and parietal thickening by increased pectin content in the cells of the bundle sheath, restricted the advance of the fungus. During the colonization process, hyphae produced vesicles in the intercellular spaces of the mesophyll. These vesicles in contact with the cell wall of the chlorophyll parenchyma caused parietal changes. Pathogen sporulation occurred only on the adaxial surface of the leaves and produced sporodochium exposed on the outer leaf surface. This study showed how P. kaki penetrates in the persimmon leaves, and the process of colonization, with epidermal alterations and the lysis and collapse of mesophyll cells in the lesioned area, and finally, the formation of reproduction structures of the pathogen.

Citrus postbloom fruit drop, caused by Colletotrichum spp., is an important disease in the Americas. The pathogen infects citrus flowers, produces orange-brown lesions on petals, and may cause the abscission of young fruit. In diseased flowers, the calyxes remain attached to the peduncle after the young fruit drop. No anatomical and microanalysis studies have been conducted to determine whether calyx tissues can be infected by Colletotrichum spp. and why calyxes remain attached to the peduncle. Based on light microscopy, we demonstrate that the ovary abscission zone exhibits a separation region composed of layers of thickened lignified walled cells, indicating that abscission involves the disruption of cell walls. The first layers of the protective zone (PZ) are composed of densely packed cells with suberized walls produced by the wound meristem. Beneath the PZ, there is a compact mass of small cells that accumulate starch grains. X-ray fluorescence microanalysis (µ-XRF) confirmed the increased accumulation of calcium in the receptacle of the persistent calyxes compared to non-inoculated citrus flowers. Moreover, the peduncle pith and the receptacle exhibit hypertrophied cells with thick walls that may be related to calyx retention. Fungal structures are not observed inside the persistent calyx tissues.

Anthracnose, caused by Elsinoe ampelina, is an economically important grapevine disease in south and southeast Brazil. Control is achieved by lime sulphur application during grapevine dormancy and foliar fungicide sprays until the berries are half-grown. This study assessed the temporal and spatial progress of grapevine anthracnose under field conditions in order to describe the disease dynamics and its relationship to pathogen survival. The experiment was carried out in a vineyard of table grape Vitis labrusca in Brazil, during the 2014 and 2015 growing seasons. The incidence of vines with diseased leaves, stems and berries and the disease severity on leaves were recorded from bud break to veraison. Monomolecular, logistic and Gompertz models were fitted by non-linear regression to the incidence and severity data over time to characterize the temporal progress. Ordinary runs, dispersion index, modified Taylor's power law and spatial hierarchy analyses were used to characterize the spatial pattern of diseased plants. The monomolecular model showed the best fit for the incidence progress, with disease progress rates ranging from 0.051 to 0.136 per day. In both seasons, the incidence of diseased plants reached 100% 1 month after bud break. However, the incidence of diseased leaves per plant was around 60% and leaf disease severity was lower than 5% for both years. Ordinary runs and dispersion index analyses revealed that diseased grapevines were distributed randomly on the majority of the assessment dates. Meanwhile, a slight aggregation of diseased vines was observed in the modified Taylor's power law analysis. Our results suggested that the progress of anthracnose incidence and severity over time was governed mainly by the income of the primary inoculum, which survived in the vineyard. Therefore, anthracnose control measures in Brazilian vineyards should be focused on the reduction in inoculum within the vineyard.

HomePlant DiseaseVol. 103, No. 7First Report of Neopestalotiopsis clavispora Causing Leaf Spot on Macadamia in Brazil PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Neopestalotiopsis clavispora Causing Leaf Spot on Macadamia in BrazilC. C. Santos, J. L. Domingues, R. F. Santos, M. B. Spósito, A. Santos, and Q. S. NovaesC. C. SantosDepartamento de Fitotecnia e Zootecnia, Universidade Estadual do Sudoeste da Bahia, 45031-900, Vitória da Conquista, Bahia, Brazil, J. L. DominguesDepartamento de Fitotecnia e Zootecnia, Universidade Estadual do Sudoeste da Bahia, 45031-900, Vitória da Conquista, Bahia, Brazil, R. F. Santos†Corresponding author: R. F. Santos; E-mail Address: ricardofeliciano@usp.brhttp://orcid.org/0000-0002-8993-5421Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, 13418-900, Piracicaba, São Paulo, Brazil, M. B. SpósitoDepartamento de Produção Vegetal, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, 13418-900, Piracicaba, São Paulo, Brazil, A. SantosDepartamento de Fitotecnia e Zootecnia, Universidade Estadual do Sudoeste da Bahia, 45031-900, Vitória da Conquista, Bahia, Brazil, and Q. S. NovaesDepartamento de Fitotecnia e Zootecnia, Universidade Estadual do Sudoeste da Bahia, 45031-900, Vitória da Conquista, Bahia, BrazilAffiliationsAuthors and Affiliations C. C. Santos1 J. L. Domingues1 R. F. Santos2 † M. B. Spósito3 A. Santos1 Q. S. Novaes1 1Departamento de Fitotecnia e Zootecnia, Universidade Estadual do Sudoeste da Bahia, 45031-900, Vitória da Conquista, Bahia, Brazil 2Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, 13418-900, Piracicaba, São Paulo, Brazil 3Departamento de Produção Vegetal, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, 13418-900, Piracicaba, São Paulo, Brazil Published Online:18 May 2019https://doi.org/10.1094/PDIS-01-19-0108-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat During March 2015, irregular light brown spots on leaves of macadamia (Macadamia integrifolia) were observed in Vitória da Conquista, Bahia, Brazil. The disease severity was estimated at around 25%. Initial disease symptoms were characterized by small spots measuring 6 to 12 mm, which enlarged and coalesced, covering an extensive leaf area. Lesions showed abundant acervuli on the adaxial surface. From diseased leaves, direct isolations were performed by picking up conidia from acervuli and placing them on potato dextrose agar (PDA). Cultures were incubated at 25°C with a 12-h photoperiod for 10 days, and four single-spore isolates were obtained. Isolates showed similar morphological characteristics, and the representative isolate MAC-01 was further investigated. Fourteen-day-old colonies grown on PDA were white with cottony aerial mycelium and abundant black globular acervuli. Conidia were clavate to fusiform, four-septate, straight or slightly curved, and measured 17.9 to 27.5 µm long × 5.1 to 6.8 µm wide (n = 100). The three median cells were dark brown, whereas the basal and apical cells were hyaline. Conidia had a single basal appendage (3.5 to 7.4 μm long; n = 100) and two to three apical appendages (16.3 to 29.3 μm long; n = 100). Morphological features were consistent with those of Neopestalotiopsis clavispora reported by Maharachchikumbura et al. (2014). To confirm species identification, the internal transcribed spacer region (ITS), a partial sequence of the β-tubulin gene (TUB2), and a partial sequence of translation elongation factor 1-alpha gene (tef1-α) were polymerase chain reaction amplified and sequenced (Maharachchikumbura et al. 2014). The resulting sequences were deposited in GenBank under accession numbers KX721071 to KX721073. BLAST searches showed 98 to 100% identity with the existing sequences of N. clavispora deposited in GenBank (accession nos.: ITS, JX398978; TUB2, JX399013; and tef1-α, JX399044). Phylogenetic Bayesian inference analysis from a combined ITS, TUB2, and tef1-α sequence alignment showed that the examined isolate belonged to the N. clavispora species. The N. clavispora clade was well supported with a Bayesian posterior probability value of 1. To confirm pathogenicity, detached healthy leaves of macadamia were superficially disinfected with 1% sodium hypochlorite solution for 2 min, washed with sterile water, air dried at room temperature, placed in Petri dishes containing sterile filter paper moistened with sterile water, and then inoculated with the pathogen. For that, 5-mm mycelial plugs were excised from a 10-day-old colony grown on PDA and placed on the adaxial surface of 25 leaves. Plates were incubated at 25°C with a 12-h photoperiod for 10 days. As a control treatment, five additional detached leaves were mock inoculated with a PDA plug. The experiment was performed twice. Two days after inoculation, all inoculated leaves showed irregular light brown spots, measuring up to 8 mm, similar to those observed in the affected orchard. As the disease progressed, spots enlarged and acervuli were formed. Control leaves were asymptomatic. N. clavispora was reisolated from the symptomatic tissues and identified as previously described, thus satisfying Koch's postulates. N. clavispora has been reported as the causal agent of leaf spot on Carya illinoinensis (Lazarotto et al. 2012) and Mangifera indica (Ismail et al. 2013). To our knowledge, this is the first report of N. clavispora causing leaf spot on macadamia in Brazil. Further studies are necessary to assess the geographic distribution and the importance of the disease in Brazilian macadamia orchards.The author(s) declare no conflict of interest.References:Ismail, A. M., et al. 2013. Eur. J. Plant Pathol. 135:619. https://doi.org/10.1007/s10658-012-0117-z Crossref, ISI, Google ScholarLazarotto, M., et al. 2012. Plant Dis. 96:1826. https://doi.org/10.1094/PDIS-07-12-0615-PDN Link, ISI, Google ScholarMaharachchikumbura, S. S. N., et al. 2014. Stud. Mycol. 79:121. https://doi.org/10.1016/j.simyco.2014.09.005 Crossref, ISI, Google ScholarThe author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 103, No. 7 July 2019SubscribeISSN:0191-2917e-ISSN:1943-7692 DownloadCaptionApple cultivar Joya Cripps Red lesions caused by Colletotrichum fructicola (Nodet et al.). Photo credit: P. Nodet. Symptoms of Lotus powdery mildew caused by Erysiphe takamatsui (Zhou et al.). Photo credit: C. Liang. Symptoms of tar spot (Phyllachora maydis) on maize leaves (Dalla Lana et al.). Photo credit: F. Dalla Lana. Metrics Article History Issue Date: 20 Jun 2019Published: 18 May 2019First Look: 2 Apr 2019Accepted: 29 Mar 2019 Pages: 1790-1790 Information© 2019 The American Phytopathological SocietyKeywordsfungitree nutsetiologypathogen detectionThe author(s) declare no conflict of interest.Cited bySpecies of the Genera Neopestalotiopsis and Alternaria as Dominant Pathogen Species Attacking Mastic Trees (Pistacia lentiscus var. Chia)21 January 2023 | Microbiology Research, Vol. 14, No. 1First Report of Neopestalotiopsis clavispora Causing Postharvest Fruit Rot on Actinidia arguta in Liaoning Province, ChinaKuikui Li, Chunlai Zhang, Wenxia Wang, Changzheng Chen, Qishun Liu, and Heng Yin18 January 2023 | Plant Disease, Vol. 107, No. 1First Report of Neopestalotiopsis clavispora Causing Leaf Spot Disease on Banana (Musa acuminata) in ChinaY. X. Qi, H. Zhang, J. Peng, F. Y. Zeng, Y. X. Xie, Q. F. Yu, and X. 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Viticulture has been expanding in tropical regions. However, the climate in these areas is generally favourable to the incidence of plant diseases, especially downy mildew. Plastic covers and warning systems have shown very positive results in disease control, but they are tools that have never been used simultaneously in a tropical area. The Vitis vinifera cv. BRS Morena table grape was evaluated as regards yield and quality under different downy mildew control strategies as carried out on vineyards trained on an overhead trellis system, covered by a black shading screen (BSS) or a braided polypropylene film (BPF), over a 3-year period. Different grapevine downy mildew management approaches defined the treatments: Co) Control (no spraying); Ca) Conventional control (calendar); Ba) "Rule 3-10" (Atti Istituto Botanico, 8, 1947, 45); Ma25) Low-infection efficiency-i(0)>25%; and Ma75) High-infection efficiency-i(0)>75% (Plant Disease, 84, 2000, 549). The occurrence of downy mildew and the amount of damage inflicted on vine yield and grape quality are directly related to the period of the crop cycle when there is rainfall. The use of the Ma75 warning system (Plant Disease, 84, 2000, 549) under braided polypropylene film resulted, for the most part, in similar vineyard productivity compared to Ca, but did not influence the number of branches and its fertility. The other warning systems decreased productivity by 31.9% compared to Ca. It was not possible to establish a relationship between the occurrence of downy mildew and its influence on grape sweetness and acidity. The use of warning systems led to a substantial reduction in fungicide sprays, approximately 66.7 to 71.3%, compared to the calendar system commonly used by the vine growers, with the Ba (Atti Istituto Botanico, 8, 1947, 45) and Ma75 controls (Plant Disease, 84, 2000, 549) leading to the highest fungicide saving.