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The effects of sublethal pesticide exposure on queen emergence and virus titers were examined. Queen rearing colonies were fed pollen with chlorpyrifos (CPF) alone (pollen-1) and with CPF and the fungicide Pristine® (pollen-2). Fewer queens emerged when larvae from open foraging (i.e., outside) colonies were reared in colonies fed pollen-1 or 2 compared with when those larvae were reared in outside colonies. Larvae grafted from and reared in colonies fed pollen-2 had lower rates of queen emergence than pollen-1 or outside colonies. Deformed wing virus (DWV) and black queen cell virus were found in nurse bees from colonies fed pollen-1 or 2 and in outside colonies. The viruses also were detected in queen larvae. However, we did not detect virus in emerged queens grafted from and reared in outside colonies. In contrast, DWV was found in all emerged queens grafted from colonies fed pollen-1 or 2 either reared in outside hives or those fed pollen-1 or 2. The results suggest that sublethal exposure of CPF alone but especially when Pristine® is added reduces queen emergence possibly due to compromised immunity in developing queens.

In una serie di verifiche condotte su zucchino in pieno campo in condizioni naturali e in ambiente controllato di serra su piantine in vaso allo stadio delle foglie cotiledonari, è stata studiata l’attività di alcuni fungicidi noti o di recente sviluppo contro l’oidio delle cucurbitacee (Podosphaera fusca). In campo si è operato su coltura estiva e i fungicidi sono stati applicati 4-5 volte a intervalli di 8-10 giorni a partire dalla comparsa dei primi sintomi; le piantine in vaso in serra sono state trattate una sola volta e quindi inoculate artificialmente con alcune popolazioni prelevate nell’azienda sperimentale. Le due prove di campo, condotte nel biennio 2010-2011, hanno confermato le prestazioni non soddisfacenti dei triazoli (penconazole) già emerse in precedenti verifiche parcellari, evidenziato una attività parziale per la miscela kresoxim-methyl+boscalid e anche per il boscalid da solo e la interessante efficacia dei due nuovi antioidici cyflufenamid e pyriofenone. I saggi di sensibilità su piantine in vaso hanno messo in evidenza una mediocre attività del boscalid e della miscela kresoxim-methyl+boscalid, confermando i dati di campo; un’efficacia ancora minore, come in campo, è stata mostrata dalle strobilurine. Per il penconazole è stata invece riscontrata una attività totale.

Made available in DSpace on 2014-06-11T19:26:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-25Bitstream added on 2014-06-13T19:34:17Z : No. of bitstreams: 1 amaro_ace_me_botfca.pdf: 2305795 bytes, checksum: bf45eb1af10803eaa72900d08ba1c13a (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) As estrobilurinas são fungicidas com efeitos fisiológicos positivos no rendimento das culturas, devido ao aumento da fotossíntese líquida e melhor balanço hormonal. O boscalida complementa a ação desses fungicidas, seja aplicado alternadamente, seja aplicado em conjunto. E, assim como as estrobilurinas, é um fungicida sistêmico que funciona preventivamente inibindo a germinação de esporos, e possui pouco efeito curativo; portanto, a aplicação preventiva desses produtos traz como benefícios, além de proteger a planta, o de incrementar a produção através de seus benefícios fisiológicos. O presente trabalho teve como objetivo avaliar o efeito da aplicação de piraclostrobina, azoxistrobina e boscalida em pepino japonês (Cucumis sativus L.) enxertado e não enxertado, em condições de ambiente protegido, visando a seus efeitos fisiológicos no metabolismo e desenvolvimento da planta, bem como no aumento da produção e qualidade dos frutos. O experimento foi conduzido em área experimental da Faculdade de Ciências Agronômicas da Universidade Estadual Paulista, Campus de Botucatu-SP em ambiente protegido. O delineamento experimental foi inteiramente casualisado, fatorial 2 x 5, sendo plantas de pepino enxertadas e plantas não enxertadas e 5 tratamentos com fungicidas: testemunha, azoxistrobina 60g ha-1, boscalid 50g ha-1, piraclostrobina 50 g ha-1, boscalid (100g ha-1) + piraclostrobina (50 g ha-1), aplicados 18 dias após o transplante a intervalos de 7 dias, via foliar. O efeito dos tratamentos foi avaliado através das observações das seguintes características: produção de frutos e massa média do fruto, trocas gasosas, índice de clorofila nas folhas e atividade das enzimas peroxidase, superóxido dismutase, catalase e nitrato redutase. Em função dos resultados obtidos, conclui-se que os fungicidas testados apresentam efeitos fisiológicos positivos nas plantas... Strobilurins are fungicides of positive physiological effects on crop yield due to increased net photosynthesis and improved hormone balance. Boscalid complements the action of these fungicides, applied alternately or together. And, as the strobilurins, is a systemic fungicide that works preemptively inhibiting germination of spores, and has little curative effect; therefore the preventive application of these products protect the plant and increases production through its physiological benefits. This experiment aimed to evaluate the effect of applying pyraclostrobin, azoxystrobin and boscalid in japanese cucumber (Cucumis sativus L.) grafted and non-grafted, in greenhouse conditions, aiming to their physiological effects on metabolism and plant development, as well as increased production and fruit quality. The study was conducted in an experimental area which belongs to the School of Agronomical Sciences (FCA), São Paulo State University (UNESP), Campus Botucatu, in greenhouse conditions. Experimental design was completely randomized, 2 x 5 factorial arrangement, including grafted cucumber plants and non-grafted plants and 5 fungicide treatments: control, azoxystrobin 60g ha-1, boscalid 50g ha-1, pyraclostrobin 50 g ha-1, boscalid (100g ha-1) + pyraclostrobin (50 g ha-1), sprayed 18 days after transplant (DAT) at 7-day intervals into leaves. The effect of the treatments was evaluated through observations of the following: fruit production and fruit weight, gas exchanges, leaf chlorophyll content and activity of peroxidase, superoxide dismutase, catalase and nitrate reductase. Based on these results, we conclude that the tested fungicides have positive physiological effects on Japanese cucumber plants grafted and non-grafted, and these effects were more evident in grafted plants, in which all fungicides increased yield, nitrate reductase activity (in early development) also antioxidative... (Complete abstract click electronic access below)

Ozone fumigation was explored as a means for degrading organic fungicide residues on fresh produce. Fungicides sorbed onto model abiotic glass surfaces or onto grape berries were fumigated separately in a flow-through chamber. Gaseous ozone at a constant concentration of 150 ± 10 ppmv (μL•L -1) selectively oxidized fungicides sorbed to model surfaces. Over 140 min, boscalid and iprodione levels did not change significantly based on a single-factor analysis of variance (ANOVA) at the 95% level of confidence (p = 0.05); however, pseudo-first-order losses resulted in observable rate constants of ozonolysis, k ozonolysis (min -1), of 0.0233 ± 0.0029 (t 1/2 ≈ 29.7 min), 0.0168 ± 0.0028 (t 1/2 ≈ 41.3 min), and 0.0127 ± 0.0010 (t 1/2 ≈ 54.6 min) for fenhexamid, cyprodinil, and pyrimethanil, respectively. The relative degradation of fungicides on berries at gaseous ozone concentrations of 900 ± 12 ppmv (μL•L -1) over 2 h was similar to that on glass; decreases in residue concentration were observed for only fenhexamid (∼64%), cyprodinil (∼38%), and pyrimethanil (∼35%) with corresponding k ozonolysis (min -1) of 0.0085 ± 0.0021 (t 1/2 ≈ 81.5 min), 0.0039 ± 0.0008 (t 1/2 ≈ 177.7 min), and 0.0036 ± 0.0007 (t 1/2 ≈ 192.5 min). Heterogeneous rate constants of gaseous ozone reacting with a sorbed fungicide, k O3(M -1•min -1), were calculated for both surfaces and indicate losses proceed ∼15-fold slower on grapes. The kinetics and mechanism of fungicide removal, supported by gas chromatography- and liquid chromatography-mass spectrometry product analyses, is discussed in the context of facilitating compliance with maximum residue level (MRL) tolerances for fresh produce. © 2011 American Chemical Society.

In a monitoring study on Stemphylium vesicarium sensitivity to boscalid, no sensitivity changes were observed compared to baseline values in 72 isolates collected in commercial pear orchards untreated with this fungicide. The same behaviour was shown by 160 isolates collected in orchards treated with boscalid even for 4 years. A preliminary sensitivity study performed on 70 Botrytis cinerea isolates from strawberries and grapes generally showed sensitivity similar to the reference-sensitive strain, even if the presence of reduced sensitivity was found in samples from an experimental strawberry field in North Italy.

This study was undertaken to determine the sensitivity of grape downy mildew (DM, Plasmopara viticola) and powdery mildew (PM, Erysiphe necator) to commonly used single-site fungicides in Virginia and nearby states. DM and PM isolates were collected from 2005 to 2007. In grape leaf disc bioassays, 92% of the DM isolates were QoI (azoxystrobin)-resistant, but none were resistant to mefenoxam. Eighty-two percent of the PM isolates were QoI-resistant, but none were resistant to boscalid and quinoxyfen. The frequency of the G143A point mutation, which confers high levels of QoI resistance, was quantified in DM and PM isolates by real-time PCR. Most of the QoI-resistant DM and PM isolates contained >95% of the 143A allele. QoI-sensitive DM isolates contained less than 1% of 143A. One out of 145 and 14 out of 154 QoI-resistant DM and PM isolates (able to grow on azoxystrobin concentration ï ³ 1 µg/ml), respectively, contained less than 1% 143A. Most PM isolates exhibited reduced sensitivity to five DMI fungicides when compared to a sensitive subgroup (n=9) and compared to published reports for unexposed populations; the resistance factor (median EC50 of the entire isolate collection divided by median EC50 of sensitive subgroup) was highest for tebuconazole (360) and myclobutanil (350), followed by triflumizole (79), triadimefon (61), and fenarimol (53). Sensitivities to all five DMI fungicides, but also azoxystrobin, were moderately to strongly correlated (pairwise r-values ranging from 0.60 to 0.88). Master of Science in Life Sciences

Riassunto E’ stata osservata una diffusa resistenza di Stemphylium vesicarium ai dicarbossimidici e la sua regressione, in seguito all’interruzione dei trattamenti, in tempi variabili a seconda della frequenza di individui resistenti selezionati nel frutteto. Si è riscontrata una resistenza incrociata del patogeno tra dicarbossimidici e fludioxonil, presente però solo in un fenotipo raro e che pertanto non costituisce un reale problema in campo. La sensibilità di S. vesicarium agli analoghi delle strobilurine, dopo circa dieci anni dalla loro introduzione in campo, non ha subito modifiche sostanziali, anche se sono stati recentemente riscontrati sporadici isolati resistenti. I noti ditiocarbammati e il recente boscalid non hanno evidenziato variazioni di sensibilità. Evolution in Italy of the sensitivity to fungicides in Stemphylium vesicarium, the causal agent of pear brown spot Abstract The control of Stemphylium vesicarium, the causal agent of pear brown spot, needs many treatments from petal fall to fruit ripening, therefore a knowledge of the effectiveness of fungicides is important. After the occurrence of the first problems in pear brown spot control in the early 1990s with procymidone, in vitro studies have demonstrated the occurrence of pathogen resistance in Italy. Further studies identified four phenotypes of S. vesicarium with different degrees of sensitivity to dicarboximides: the sensitive (S), the S+ slightly resistant to procymidone and iprodione, the R1 highly resistant to procymidone and moderately resistant to the other dicarboximides and the R2 highly resistant to all dicarboximides. These phenotypes are spread in all pear growing areas of Po valley. Fortunately the sensitive phenotype is still the most frequent followed by the R1 phenotype. The other resistant phenotypes are very rarely found in the field. Another important aspect considered was the possibility of the resistance to regress. The frequency of the phenotypes inside the populations of each orchard influences the time of resistance regression. If the resistant frequency is high more years of interruption of treatments are needed. The cross resistance between dicarboximides and phenylpyrroles was observed only in R2 phenotype, therefore it does not represent a real problem in the field because of their rarity. A wide monitoring was carried out also to evaluate the sensitivity of S. vesicarium to strobilurins. Ten years after their introduction in the field, they are still active and with EC50 values comparable to baseline ones, albeit the first few resistant isolates have been found since 2006. Only one of these cases was linked to a failure of strobilurins in pear brown spot control and it has appeared after several years of intense use of these compounds. Nevertheless this is an interesting information, because it demonstrates that S. vesicarium is able to develop strobilurin resistance and therefore it underlines again the importance of following strictly anti-resistance strategies. No changes in sensitivity were noted in S. vesicarium to dithiocarbamates, multi-site fungicides with a low resistance risk but widely used against pear brown spot since its appearance in the late 1970s. The study of S. vesicarium sensitivity to boscalid had the same result, in fact two years after its registration on pear in Italy, the level of sensitivity is comparable to that of populations collected before its introduction in the field.

Made available in DSpace on 2014-12-03T13:11:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-01-01Bitstream added on 2014-12-03T13:22:34Z : No. of bitstreams: 1 WOS000328276600035.pdf: 690871 bytes, checksum: 4d4a579473505c9e8bbb3ab8276495da (MD5) The present work evaluated the effect of strobilurins, boscalid, plant growth regulators and vegetal extracts on the physico-chemical quality of tomato fruits (Solanum lycopersicum L.), hybrid Giuliana. The fruits from each treatment were selected and separated in 4 repetitions: control, pyraclostrobin, boscalid, pyraclostrobin + boscalid, IBA + GA(3) + kinetin, GA(4+7) + benzylaminopurine and vegetal extract. The first application was carried out at 30 days after transplant and the following at every 15 days. The evaluations were: weight loss, titratable acidity (TA), soluble solids (SS), SS/TA relation, pH, ascorbic acid content, texture, total soluble sugars (TSS), activity of pectin methyl esterase (PME) and polygalacturonase (PG). The SS content, responsible for fruit flavor, varied accordingly to the treatment, being highest for GA(4+7) + benzylaminopurine and lowest for the control. The same occurred regarding the SS/AT relation. The fruits were kept on the shelf for 9 days, at room temperature, being that at the end of this period several treatments still presented fruit in optimal consumption conditions, notably the boscalid treatment, which presented lowest weight loss, followed by pyraclostrobin. Therefore, it can be concluded that the application of the treatments did not modify the values for pH, AT and AST of the fruits. The highest PME activity was observed for the treatments with boscalid and the mixture of boscalid and pyraclostrobin, while the lowest PG activity occurred in the control and the pyraclostrobin treatment, indicating that some products accelerated the process of demethylation of pectins by PME, facilitating the action of PG. Univ Estadual Paulista, Fac Ciencias Agron, UNESP, Dept Prod Vegetal, Botucatu, SP, Brazil UNESP, Fac Ciencias Agron, Dept Prod Vegetal, Botucatu, SP, Brazil UNESP, Inst Biociencias, Dept Bot, Botucatu, SP, Brazil Univ Estadual Paulista, Fac Ciencias Agron, UNESP, Dept Prod Vegetal, Botucatu, SP, Brazil UNESP, Fac Ciencias Agron, Dept Prod Vegetal, Botucatu, SP, Brazil UNESP, Inst Biociencias, Dept Bot, Botucatu, SP, Brazil

Bark canker caused by Seiridium cardinale is the most destructive disease of Cupressus and several Cupressaceae in many temperate regions and particularly in the Mediterranean area. Chemical prevention represents the most effective and essential means of control to protect plant production in nurseries and young plantations. The European Directive 2009/128/CE and CE 1107/2009 application have drastically reduced the number of chemicals that can be used in agriculture, including the benzimidazolic compounds that had shown the best results in preventing S. cardinale canker. It is therefore urgent to find alternative fungicides to replace the banned compounds. The purpose of the present work was to assess some fungicides through in vitro tests and pre- and post-inoculation sprayings on Cupressus sempervirens, for the control of S. cardinale. The active ingredients boscalid, fosetyl-aluminium, triadimenol and azoxystrobin were compared with thiophanate-methyl as reference. The effectiveness of thiophanate-methyl in reducing canker development was confirmed especially when it was applied to trees before they were inoculated with S. cardinale. Azoxystrobin was as effective as thiophanate-methyl in the pre-inoculation trials. boscalid prevented conidial germination and mycelial growth of S. cardinale in vitro and appeared a promising contact fungicide for the prevention of cypress canker. Azoxystrobin and boscalid are listed in a less hazardous class than thiophanate-methyl, and has less risk for the environment and for users.