Eficiência de tratamentos inseticidas no controle da traça-do-cacho da videira.

2015

No evidence of transmission of grapevine leafroll-associated viruses by phylloxera (Daktulosphaira vitifoliae).

Abstract Grapevine leafroll disease is associated with several species of phloem-limited grapevine leafrollassociated viruses (GLRaV), some of which are transmitted by mealybugs and scale insects. The grape phylloxera, Daktulosphaira vitifoliae (Fitch) Biotype A (Hemiptera: Phylloxeridae), is a common vineyard pest that feeds on the phloem of vine roots. There is concern that these insects may transmit one or more GLRaV species, particularly GLRaV-2, a species in the genus Closterovirus. A field survey was performed in vineyards with a high incidence of grapevine leafroll disease and D. vitifoliae was assessed for acquisition of GLRaV. In greenhouse experiments, the ability of D. vitifoliae to transmit GLRaV from infected root sections or vines to co-planted virus-free recipient vines was tested. There were no GLRaV-positive D. vitifoliae in the field survey, nor did D. vitifoliae transmit GLRaV- 1, ?2, ?3, or -4LV in greenhouse transmission experiments. Some insects tested positive for GLRaV after feeding on infected source vines in the greenhouse, however there was no evidence of virus transmission to healthy plants. These findings, in combination with the sedentary behaviour of the soil biotype of D. vitifoliae, make it unlikely that D. vitifoliae is a vector of any GLRaV.

Current Situaion of Eurhizococcus brasiliensis (Hemiptera: Margarodidae) in Brazil.

2016

Mealybugs (Hemiptera: Pseudococcidae) associated with persimmon Diospyros kaki L. (Ebenaceae) in Southern Brazil.

Temperate fruit production is an important economic activity in Southern Brazil. In this region, persimmon Diospyros kaki L. (Ebenaceae) is grown in small farms for domestic consumption and internal market. Mealybugs are o*en found in at least 50% of the orchards causing damages on fruits due to the honeydew secretion. However, there is a lack of informatin about species composition damaging orchards in Southern Brazil. In this work, we present a survey of mealybugs associated with persimmon trees in the Serra Gaúcha Region, Rio Grande do Sul, Brazil.

Danos prolongados.

Com ataque a todos os tecidos verdes e jovens da videira, o fungo Elsinoe ampelina, causador da antracnose da videira, além de ocasionar perdas que podem chegar a 100% da produção, afeta toda a parte aérea da planta e compromete o seu desenvolvimento nos anos seguintes. De difícil controle, a recomendação é de que se devem adotar medidas preventivas desde a implantação da cultura, começando pela escolha do local de plantio.

Evaluation of the productive and vegetative aspects of the cultivar 'Imperial Gala' apple tree with EM-9 interstem in different lengths.

The obtaining of a compact plant, with less vigor and high productivity, equivalent to a conventional plant, constitutes a strong tendency in the current horticulture, aiming at a raising of the fruit production at the same planted area. One of the techniques that have had success nowadays is the interstem use. This study was developed in a commercial orchard of Randon Agro Silvo Pastoril S.A. (RASIP), located in the Rio Grande do Sul state, Brazil. The purpose of this work was to evaluate the vegetative and productive development of apple trees of 'Imperial Gala' with different lengths of EM-9 interstem. The treatments consisted of five interstem lengths: 10, 15, 20, 25, 30 cm. In the seventh year of implantation the following parameters were evaluated: the height of the plant, the diameter of the 'Imperial Gala' 5 cm above the second graft point, the volume of the tree-head (height, width and length), the number of bud per branch, and the number of fruits per lineal centimeter of branch. Through this study it could be concluded that the greater interstem (30 cm) presented better indices with relation of vigor control. However, the number of fruits per lineal centimeter of branch with the interstem of 10 cm offered only significant superiority, when compared with the interstem of 30 cm. Using interstem technique allows to gather the benefits of the rootstock 'Marubakaido' and to control excessive vigour with the interstem EM-9.

Sensory evaluation of 'Rocha' pears grown in Brazil.

2010

The infection of soybean leaves by Phakopsora pachyrhizi during conditions of discontinuous wetness.

The ability of Phakopsora pachyrhizi to cause infection under conditions of discontinuous wetness was investigated. In in vitro experiments, droplets of a uredospore suspension were deposited onto the surface of polystyrene. After an initial wetting period of either 1, 2 or 4 h, the drops were dried for different time intervals and then the wetness was restored for 11, 10 or 8 h. Germination and appressorium formation were evaluated. In in vivo experiments, soybean plants were inoculated with a uredospore suspension. Leaf wetness was interrupted for 1, 3 or 6 h after initial wetting periods of 1, 2 or 4 h. Then, the wetting was re-established for 11, 10 or 8 h, respectively. Rust severity was evaluated 14 days after inoculation. The germination of the spores and the formation of the appressoria on the soybean leaves after different periods of wetness were also quantified in vivo by scanning electron microscopy. P. pachyrhizi showed a high infective capacity during short periods of time. An interruption of wetness after 1 h caused average reductions in germination from 56 to 75% and in appressorium formation from 84 to 96%. Rust severity was lower in all of the in vivo treatments with discontinuous wetness when compared to the control plants. Rust severity was zero when the interruption of wetness occurred 4 h after the initial wetting. Wetting interruptions after 1 and 2 h reduced the average rust severity by 83 and 77%, respectively. The germination of the uredospores on the soybean leaves occurred after 2 h of wetness, with a maximum germination appearing after 4 h of wetness. Wetness interruption affected mainly the spores that had initiated the germination.

Reference gene selection for gene expression studies in apple.

2011

Seletividade de acaricidas a ácaros praga da cultura da videira.

2011

Detecção de oito vírus em videiras por meio de RT-PCR em tempo real.

2011

South American fruit fly Anastrepha fraterculus damage and management in Vitis vinifera table grapes in southern Brazil.

2011

Selection of Trichogramma pretiosum lineages for control of Grapholita molesta in peach.

Grapholita molesta (Lepidoptera: Tortricidae) é uma das principais pragas do pessegueiro no Brasil, causando perdas de 3-5% da produção. Dentre os agentes de controle biológico Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) tem sido encontrado nos pomares de pessegueiros. O objetivo deste trabalho foi estudar a criação de T. pretiosum em ovos de G. molesta e Anagasta kuehniella (Lepidoptera: Pyralidae) e selecionar as linhagens de T. pretiosum com potencial de controle de G. molesta. A seleção de linhagens foi realizada com cinco populações de T. pretiosum coletadas em pomares de pessegueiro cultivados sob o sistema orgânico de produção. O estudo foi realizado em condições controladas de temperatura (25 ± 2°C), umidade relativa (70 ± 10%) e fotofase (14h). Ovos de G. molesta são hospedeiros adequados ao desenvolvimento de T. pretiosum uma vez que, nas variáveis estudadas número de ovos parasitados, porcentagem de parasitismo e razão sexual, os valores foram equivalentes aos criados em ovos de A. kuehniella . O maior parasitismo de ovos de G. molesta ocorreu com posturas de até 48h de desenvolvimento embrionário. Das linhagens de T. pretiosum coletadas, H08, PO8, PEL e L3M apresentaram melhor desempenho biológico, sendo, portanto, indicadas para estudos de semi-campo e campo para o controle biológico da mariposa-oriental.

Inibição da ação do etileno sobre variáveis de qualidade de maçãs 'Gala' mantidas em armazenamento refrigerado.

O objetivo deste trabalho foi avaliar a influência do etileno em variávies de qualidade de maçãs 'Gala' armazenadas por 6 meses sob refrigeração (temperatura de 0°C e umidade relativa de ± 95%).

Firmeza de polpa e aceitabilidade como parâmetros para indicação do amadurecimento de peras 'Abate Fetel'.

Dada à importância do estabelecimento de parâmetros relacionados ao amadurecimento, este trabalho teve por objetivo avaliar a firmeza de polpa e a aceitabilidade como parâmetros para indicar o amadurecimento e a qualidade ótima para consumo de peras 'Abate Fetel'.