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Bento Gonçalves, Brazil

Bernardi D.,University of Sao Paulo | Botton M.,Embrapa Grape and Wine | da Cunha U.S.,Eliseu Maciel Agronomy School | Bernardi O.,University of Sao Paulo | And 3 more authors.
Pest Management Science | Year: 2013

BACKGROUND: The spider mite, Tetranychus urticae, is the major strawberry pest in Brazil. The main strategies for its control comprise synthetic acaricides and predatory mites. The recent register of a commercial formula of azadirachtin (Azamax® 12 g L-1) can be viable for control of T. urticae. In this work, the effects of azadirachtin on T. urticae and its compatibility with predatory mites Neoseiulus californicus and Phytoseiulus macropilis in the strawberry crop were evaluated. RESULTS: Azadirachtin was efficient against T. urticae, with a mortality rate similar to that of abamectin. In addition, the azadirachtin showed lower biological persistence (7 days) than abamectin (21 days). Azadirachtin did not cause significant mortality of adult predatory mites (N. californicus and P. macropilis), but it did reduce fecundity by 50%. However, egg viability of the azadirachtin treatments was similar to that of the control (>80% viability). The use of azadirachtin and predatory mites is a valuable tool for controlling T. urticae in strawberry crop. CONCLUSIONS: Azadirachtin provided effective control of T. urticae and is compatible with the predatory mites N. californicus and P. macropilis. It is an excellent tool to be incorporated into integrated pest management for strawberry crop in Brazil. © 2012 Society of Chemical Industry.

Youssef K.,Egyptian Plant Pathology Research Institute | Roberto S.R.,State University Londrina | Chiarotti F.,State University Londrina | Koyama R.,State University Londrina | And 2 more authors.
Scientia Horticulturae | Year: 2015

The objective of this work was to evaluate the incidence of gray mold of the new seedless table grape 'BRS Vitoria' grown under subtropical conditions, during the cold storage. Grape bunches were obtained from a commercial field trained on overhead trellis and located at Marialva, state of Parana (PR) (South Brazil). The trials were conducted on two consecutive seasons, regular and out of season crops of 2013. Grapes were subjected to the following treatments in a cold chamber: (i) cold storage at 0° (control); (ii) cold storage at 0°C with SO2 pad; (iii) cold storage at 0° and inoculated with Botrytis cinerea suspension; (iv) cold storage at 0°C with SO2 pad and inoculated with B. cinerea suspension. The randomized design was used as statistical model with four treatments and five replicates, with 20 bunches per plot. The incidence of gray mold on grapes was evaluated at 30 days after the beginning of cold storage and at 7 days at room temperature after the end of cold storage. Grape physicochemical variables, such as bunch mass, berry firmness, bunch mass loss, skin color, soluble solids (SS), titratable acidity (TA) and SS/TA were evaluated at the beginning and 30 days after the period of cold storage. The results of this study showed that a good reduction of gray mold was achieved by SO2 during cold storage and shelf life periods. Also, bunch mass, berry firmness, mass loss, color, SS, TA and SS/TA of the grape tested was not negatively affected by SO2 treatment. A good control of gray mold could be achieved on 'BRS Vitoria' table grapes by sulfur dioxide during storage without affecting fruit quality. © 2015 Elsevier B.V.

Alves S.A.M.,Embrapa Grape and Wine | Beresford R.M.,The New Zealand Institute for Plant and Food Research Ltd
New Zealand Plant Protection | Year: 2013

Ascospores of Venturia inaequalis constitute the principal source of primary inoculum for epidemics of apple black spot (scab). Mathematical models that describe ascospore release have been developed in USA, New Zealand and Italy. These models are based upon degree-day accumulation. In this work, the seasonal pattern of released ascospores of V. inaequalis in Vacaria, Brazil, was evaluated. During four apple growth seasons (2009 to 2012) the natural release of ascospores from ive orchards was recorded. The cumulative percentage of ascospore release was predicted using three different degreeday models. The released ascospore data showed the best it to the model developed in Italy, with a start date of 22 August rather than the phenological stage of apple bud break. It is concluded that in regions with warm winter temperatures, models that use bud break to initiate ascospore maturation will tend to underestimate availability of ascospores. © 2013 New Zealand Plant Protection Society.

De Meyer G.A.,Santa Catarina State University | Rufato L.,Santa Catarina State University | Sanhueza R.M.V.,Proterra | De Rufato A.R.,Embrapa Grape and Wine
Acta Horticulturae | Year: 2016

In Brazil, leaf abscission in apple trees can occur prematurely due to infection by Glomerella leaf spot (Colletotrichum gloeosporioides). The extent of leaf fall is correlated with ethylene production resulting from the reaction by the host to prevent the dissemination of the pathogen. The aim of this study was to verify the impact of the aminoethoxyivinylglycine (AVG) on the process of leaf abscission in plants exhibiting Glomerella leaf spot symptoms. The experiment was conducted in the spring of 2011 in 'Maxi Gala'/M9 young apple trees (2 years old) in pots under greenhouse conditions at 22±2°C, with 80±5% relative humidity, (28°30'52"S and 50°52'58"W, 950 m). Plants without disease symptoms were artificially inoculated with C. gloeosporioides, and treatments were applied when the leaves had symptoms of infection. The experiment included 7 treatments with AVG and/or the fungicide Folpet (mg L-1 active ingredient - a.i.) as follows: AVG 60, AVG 150, AVG 30 + Folpet 120, AVG 45 + Folpet 120, AVG 60 + Folpet 120, AVG 150 + Folpet 120, Folpet 120 alone and the untreated control. Assessments of percentage defoliation were made weekly until 68 days after spraying (das). The results indicated that AVG in doses 60 and 150 mg L-1 resulted in a reduced level of defoliation, compared with the fungicide treated trees, and abscission was equivalent to control at 21 das. After the disease is established and is not controlled by fungicide there was an increase in leaf abscission compared to the control.

De Sa Borges R.,Embrapa Products and Market | da Silva G.A.,Embrapa Grape and Wine | Roberto S.R.,State University Londrina | de Assis A.M.,State University Londrina | Yamamoto L.Y.,State University Londrina
Scientia Horticulturae | Year: 2013

The aim of this study was to evaluate the total phenols, anthocyanins, tannins, favorable oxi-redox activity (oxi-redoxf) and juice color of six clones of the 'Concord' grapevine on three rootstocks. Samples of juice obtained from 'Concord' clones '22', '28', '49', '202', '211' and '225' grafted onto 'IAC 766', 'IAC 572' and '420-A' were evaluated. The trial was conducted at the Technology Center of COROL Cooperative, Rolândia, PR, Brazil. A completely randomized design was used as the statistical model, arranged in a factorial system (6 clones×3 rootstocks) with three replications. The grapevines were trained in an overhead trellis system spaced at 4.0m×2.0m, and the evaluations were performed at the 2010/2011 harvest. The juice samples were prepared using the Welch process. The juice from 'Concord' clone '202' presented higher means regarding to total phenols and tannins, color intensity and yellow and red color at 420 and 520nm. The juices did not differ significantly among themselves (P>0.05) with regard to the oxi-redoxf activity, anthocyanins and violet color at 620nm, however, the use of rootstock '420-A' resulted in higher means for total phenols, tannins and oxi-redoxf activity, whereas 'IAC 572' resulted in a reduction in the color intensity of the juice. © 2013 Elsevier B.V.

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