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Here, published crop disease risk simulations are summarized, which were driven by climate change scenarios on a timescale terminating between 2001 and 2100. Thirty different agricultural and horticultural crops were specifically considered. Wheat diseases (mainly leaf rust) were most often simulated, followed by rice diseases (mainly leaf blast), grapevine diseases (mainly downy mildew) and potato diseases (mainly late blight). Most simulations suggest that within the projection period simulated, crop disease risk will more often increase (86 simulations) than decrease (45 simulations) or remain similar (12 simulations). The majority of crop disease risk simulations focus on Europe and Brazil. For example, there is agreement across crop disease risk simulations that in Europe the risk of leaf rust of wheat will increase. In other cases, there is disagreement across crop disease risk simulations, for example, due to contemporary climatic differences of locations. Therefore, it is risky to extrapolate results across locations. Mitigation and adaptation methods should be more often integrated in the crop disease risk simulations in order to inform about potential methods to reduce disease risk in future. [ABSTRACT FROM AUTHOR]

Ripe rot is one of the most important bunch diseases of grapes in the highlands of southern Brazil and a matter of concern for winegrowers. Sixty‐one strains isolated from berries of Vitis labrusca and V. vinifera varieties with symptoms were classified by phylogenetic analysis of the sequences of β‐tubulin, glyceraldehyde‐3‐phosphate dehydrogenase, D1/D2 domain of 28S rDNA, and rDNA internal transcribed spacer. They were also characterized by morphology, and their pathogenicity was evaluated. The combined molecular data allowed identification of six Colletotrichum species: C. fructicola, C. kahawae and C. viniferum (gloeosporioides complex), C. limitticola, C. nymphaeae (acutatum complex), and C. karstii (boninense complex). This is the first report of C. karstii and C. limitticola associated with the ripe rot of grapes. Morphological characteristics varied within and among species, confirming their separation at the complex level. Pathogenicity tests on V. vinifera berries showed that the most prevalent species, C. viniferum (37.8%) and C. fructicola (36.1%), were more virulent than the less prevalent species C. limitticola and C. karstii. Our findings indicate that there is a high diversity of Colletotrichum species associated with ripe rot disease of grapes in Brazil. There were no clear differences in the distribution of Colletotrichum species between V. labrusca and V. vinifera varieties. The determination of fungal species responsible for grape ripe rot in Brazilian vineyards may contribute to further epidemiological studies and the development of more efficient prophylactic methods for ripe rot management. [ABSTRACT FROM AUTHOR]

Among grapevine (Vitis spp.) pathogens, viruses stand out, considering that this fruit plant is broadly susceptible to them and that they cause several diseases, reducing quality and yield of grape production. However, detecting and identifying viral infections in grapevines can be challenging. The objectives of this study were to detect grapevine viral pathogens by high-throughput sequencing (HTS) and identify grapevine viruses associated with plant propagation material from different origins. A comprehensive picture of a vine exhibiting virus-related symptoms was generated. The detected virome included four different pathogens and their variants. In addition, the incidence of seven viral pathogens was determined in samples collected in three vineyards of the main grape-growing region of Brazil. It is suggested that the observed infections could be related to the technological level of the production system adopted by these grape growers. [ABSTRACT FROM AUTHOR]

Grapevines are attacked by diseases and pests, and strategies used by wine makers for the control of these involve the use of agrochemicals, causing in balancing of predator-prey ratios. The spider mite Panonychus ulmi causes damage to grapevines in the South of Brazil, whereas Neoseiulus californicus is the most frequently used predatory mite in biological control of tetranychids in Brazil. The effects of 13 agrochemicals used in the wine growing sector and their effect on P. ulmi and N. californicus were evaluated. A residual contact method by air-brush spraying was used. The corrected mortality rate and the effect of products on mite reproduction were evaluated and eggs were monitored until larval hatching to evaluate viability. Products were classified according to the total effect caused, in toxicity classes proposed by the IOBC/WPRS Working Group "Pesticides and beneficial organisms". Lambda-cyhalothrin was the product that caused the highest mortality rate of P. ulmi : 76% within 24 h after spraying, reaching 100% mortality within 72 h. The other products caused mortality between 50% and 60% at 96 and 120 h. None of the products fitted into the harmless category; however, the fungicides azoxystrobin, metiram + pyraclostrobin, copper hydroxide and mancozeb showed low toxicity to the pest and predator. So, it is probably they can be used for doses management without disrupting the mite biocontrol. The products recommended which were harmful to the predator were cymoxanil + mancozeb, tetraconazole, lambda-cyhalothrin, famoxadone + mancozeb. These results can be used to develop guidelines on the best products to be used in the field, thus creating pest management practices that preserves predatory mite populations in vineyards. • A total of 13 agrochemicals used in vineyards were tested. • Lambda-cyhalothrin caused the highest mortality to P. ulmi within 72 h. • None of the products evaluated proved to be harmless for N. californicus. • Higher mortality rate was caused by cymoxanil + mancozeb on N. californicus. [ABSTRACT FROM AUTHOR]

Two American grapevine leaf rust (GLR) fungi, Phakopsora muscadiniae and P. uva , were found to be phylogenetically different from Asian-Australasian GLR fungi. In the phylogram based on rDNA region sequences, a clade of the American fungi was sister to an inclusive clade of three autoecious species on Meliosma and a heteroecious species host-alternating between Meliosma and Parthenocissus . An invasive Brazilian GLR fungus (as P. meliosmae-myrianthae ) was included in the Asian-Australasian GLR fungi clade, or the clade of the Thai population of Phakopsora sp. It could be assumed that the Brazilian GLR fungus originated from an inadvertently introduced Thai population. [ABSTRACT FROM AUTHOR]

Contamination by ochratoxin A (OTA) in agricultural products grown in regions with different climate conditions is difficult to predict since this contamination depends on a complex interaction of factors. Thus, the aim of this study was to use a mathematical model to predict OTA synthesis by Aspergillus carbonarius in grape (Vitis vinifera) of the Syrah variety grown in three wine-growing regions, considering the mean monthly temperature of the environment and water activity and pH of grape. Results indicate that the greatest risks of contamination by the toxin are in the months when the temperature is below 19.0°C and these months are just before grape harvest. However, with the predicted increase in temperature, these conditions change, i.e., they are no longer favorable to OTA synthesis, thus reducing the risks of the presence of the toxin in cultivated grapes. For the tropical region, the current environmental temperature and water availability to grape are not favorable to OTA synthesis, showing that even if A. carbonarius is present in the crop, it does not encounter suitable conditions of environmental temperature, water activity, and grape pH to synthesize OTA. [ABSTRACT FROM AUTHOR]

Grapevine fleck, rugose wood and leafroll are three grapevine viral diseases whose causal agents (or associated viruses) respectively are Grapevine fleck virus (GFkV), Grapevine virus D (GVD) and Grapevine leafroll-associated virus 5 and 6 (GLRaV-5 and -6). The objective of this work was to perform a partial molecular characterization of local isolates of these four viral species that infect grapevines. The nucleotide and deduced amino acid sequences of complete genes of the coat protein (CP) (of GFkV), the CP and the RNA binding protein (of GVD), the CP and the partial hHSP70 gene (of GLRaV-5) and the partial hHSP70 gene (of GLRaV-6) were aligned and compared in silico with other isolates. These data extend the available information about Brazilian isolates of GFkV, GLRaV-5 and -6, and reports for the first time the GVD occurrence in Brazil. [ABSTRACT FROM AUTHOR]

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In the vineyards of the Region of the Campanha of Rio Grande do Sul, Brazil, the grape rust mite Calepitrimerus vitis (Nalepa, 1905) (Acari: Eriophyidae), has been found frequently since the 2004/2005 harvest associated with symptoms of tanning on the leaves. The fluctuation of C. vitis in 'Cabernet Sauvignon' was studied in a commercial vineyard located in Candiota, RS, during the agricultural years 2007/2008 (November-June) and 2008/2009 (October-May). The sampling was carried out on the leaves and by using traps constituted by double-faced adhesive installed in the branches of production. The populational peak in the first year occurred in March, 2008, which recorded 0.34 individuals per square centimeter of the abaxial face of the medium leaves and 29.48 individuals per traps. In the second year of the experiment, the populational peak was less intense and occurred on October, 2008, when it was detected 0.11 individuals per square centimeter of the medium leaves abaxial faces and 0.43 individuals per traps. It was detected that the beginning of the displacement of C. vitis to hibernation places occurs on summer, starting in February. The adhesive traps were more efficient in identifying the presence of C. vitis in the vineyard than the direct evaluation on leaves. A positive correlation was found between the number C. vitis on the abaxial surface of leaves and percentage of leaves infested. [ABSTRACT FROM AUTHOR]

The ground-pearl Eurhizococcus brasiliensis is an important insect pest of grapes. Nowadays, its biology is still barely known and studies related to its secondary symbionts are virtually non-existent. Our main goal was to evaluate the bacterial diversity associated with cysts of E. brasiliensis using a culture-dependent approach . Six different isolation media were used and shown to be suitable for culturing bacteria associated with E. brasiliensis. A total of 39 bacteria strains were isolated and classified into 10 different morphotypes. The ISP-4 medium was the most suitable for bacteria isolation from cysts of the ground-pearl, providing the highest number of morphotypes. 16S rDNA gene analysis demonstrated a high diversity of bacteria associated with cysts, with six Pseudomonas chlororaphis isolates (the most predominant morphotype) and three different morphotypes of Bacillus spp. as the most representative genera. The phylogenetic analysis showed close affinity between the isolated morphotypes and bacterial strains usually isolated from plant and soil samples. Sphingopyxis and Stenotrophomonas were isolated for the first time from arthropods. Although it was not possible to determine the primary source of infection by these bacteria, our data suggests that these microorganisms may be transitory and acquired from the environment. [ABSTRACT FROM AUTHOR]

The viticulture of the north of Parana state differs from other regions, because in this area two crops are obtained a year, a regular and an out of season ones. However, the hot and humid climate of the region favors the occurrence of downy mildew (Plasmopara viticola), an alternative to minimize this problem is the use of grape production under protected cultivation. The study aimed to evaluate the out of season production of grapevine 'BRS Clara' on 'IAC 572 Jales' and 'IAC 766 Campinas' rootstocks, submitted to different types of protected cultivation. The randomized block design was used as a statistical model with four replications arranged in a factorial 7x2 (seven kinds of protected cultivation and two rootstocks). The treatments were: a. plastic screen without fungicides for downy mildew; b. plastic screen with fungicides for downy mildew (standard control of the region); c. plastic cover without fungicides for downy mildew; d. plastic cover and 50% of reduction of the standard fungicides for downy mildew; e. plastic cover and 75% of reduction for the standard fungicide mildew; f. plastic cover with phosphite and copper and; g. plastic cover without fungicides. The rootstocks 'IAC 766' and 'IAC 572' are suitable for the production of 'BRS Clara' in north of Parana state; the use of plastic cover allows a reduction up to 75% of the number of applications of fungicides in 'BRS Clara'; the plastic cover itself is not sufficient to prevent the occurrence of downy mildew in bunches under conditions of high humidity. [ABSTRACT FROM AUTHOR]

Brazilian ground pearl Eurhizococcus brasiliensis (Hempel in Wile) (Hemiptera: Margarodidae) is one of the main grape pests in southern Brazil. The resistance of Vitis rotundifolia cultivars (Bountiful, Chief, Creek, Dixie, Magnolia, Magoon, Noble, Regale, Roanoke, Sumith and Topsail) to Brazilian ground pearl was evaluated by comparison with 101-14 (Vitis riparia x Vitis rupestris) rootstock. The experiment was conducted in a naturally infested field, by measuring pest infestation on roots, dry weight of plants (leaves + roots) and mortality during three years. V. rotundifolia cultivars showed a reduced infestation by the pest, a higher vigor and lower mortality when compared to 101-14 rootstock. All 101-14 plants were killed by the pest after the second year in the field. The cultivars Bountiful, Chief, Magoon, Magnolia and Regale had low pest infestation, showing antixenosis or antibiosis resistance. The Dixie cultivar showed a higher pest infestation; however, this was associated with high plant vigor, suggesting the existence of tolerance. The results show that V. rotundifolia cultivars Bountiful, Chief, Magoon, Magnolia and Regale showed a low infestation by E. brasiliensis and can be alternatives for direct fruit production or pest resistance source in plant breeding programs. [ABSTRACT FROM AUTHOR]

Genomic DNAs isolated from strains of Xylella fastidiosa that caused citrus variegated chlorosis, coffee leaf scorch, Pierce's Disease of grapevine, and plum leaf scorch were analyzed by arbitrarily primed polymerase chain reaction. Purified DNA was amplified under nonstringent conditions with single primers 21 nucleotides (nt) long. Thirty-nine amplification products were observed that were useful to distinguish among the strains and to derive a similarity matrix and construct a phenogram showing possible relationships among the strains. Strains isolated from diseased coffee and citrus in Brazil were closely related to each other (coefficient of similarity of 0.872), but only distantly related to a strain isolated from diseased grapevine in the USA (coefficient of similarity of 0.650). Strains of Xylella fastidiosa isolated from diseased plums in the USA and Brazil clustered with strains from different hosts isolated from their respective countries of origin. Thus, there may be two quite dissimilar clusters of strains of Xylella fastidiosa, one in North America and the other in South America. Each cluster contains strains that can cause disease in plum. The methods described provide a convenient and rapid method to distinguish between strains of Xylella fastidiosa that cause diseases of coffee and citrus in the same region of Brazil. This has not been possible previously. This will potentially enable the two strains to be distinguished in alternate hosts or in insect vectors. [ABSTRACT FROM AUTHOR]

Occurrence of crown gall on grape was observed in a vineyard in Minas Gerais State, Brazil. Isolations of the pathogen yielded a bacterium which incited galls on grapevine, tomato and bryophillum. The bacterium was confirmed as Agrobacterium tumefaciens and its characterization showed it co be biovar 3. This is the first report on the occurrence of the biovar 3 of A. tumefaciens on grapevine in Brazil. [ABSTRACT FROM AUTHOR]

Anthracnose caused by Elsinoë ampelina is one of the most serious diseases affecting grapevine production worldwide. Previous studies have described many structural and histochemical changes in grapevine leaves associated with E. ampelina colonization and the presence of ascus-like structures in the lesions. In this paper, we characterized the colonization and reproduction of E. ampelina in grapevine tendrils, stems and berries using light, epifluorescence and scanning electron microscopy. In the early stages of colonization, shape changes and the collapse of epidermal and parenchyma cells were more pronounced in the center of lesions. At this stage, pectic substances accumulated inside the parenchyma cells and hyphae were observed colonizing tissues inter- and intracellularly, including tracheary elements. As colonization evolved, lesions enlarged and infected tissues became necrotic and collapsed. Tyloses and conidiogenous cells producing conidia were observed in the tracheary elements. Conidiogenous cells and conidia were also present on the lesion surface. On the same lesions, bitunicate asci containing two-to three-celled ascospores were observed on the surface and throughout the stromatic tissue. Our analyses showed that both sexual and asexual stages of E. ampelina occur from the beginning of the epidemic, which may help to explain the explosive nature of the disease when early stages of grapevine development coincide with rainy seasons. ∙ Anthracnose caused by Elsinoë ampelina is one of the most serious diseases affecting vine production worldwide. ∙ The pathogen is pleiomorphic, but the sexual stage of E. ampelina does not occur as regularly as the asexual stage. ∙ Before our study, the sexual stage of E. ampelina had not yet been reported in Brazil. ∙ We demonstrated that both sexual and asexual stages of E. ampelina can occur at the same lesion. ∙ It was showed that E.ampelina , a non-wilt pathogen, is able to invade, growth and reproduce within the tracheary elements. [ABSTRACT FROM AUTHOR]