Gathered from the Vine: A Survey of Seven Grapevine Viruses Within New England Vineyards.

Vineyards in the Southeastern New England American Viticultural Area were surveyed for the incidence of seven major viruses: grapevine leafroll-associated viruses (GLRaV-1, GLRaV-2, GLRaV-3, and GLRaV-4), grapevine fanleaf virus (GFLV), tomato ringspot virus (ToRSV), and tobacco ringspot virus (TRSV). Viruses were detected by DAS-ELISA and confirmed by RT-PCR and Sanger sequencing. Multiple viruses were present in 19 out of the 25 vineyards surveyed between 2018 and 2020. GLRaV-3 (27.59%) was the most prevalent virus followed by GLRaV-4 (14.90%), GLRaV-1 (13.52%), GLRaV-2 (11.03%), ToRSV (6.34%), GFLV (5.24%), and TRSV (2.62%). Furthermore, phylogenetic analyses of the viral partial genome sequences acquired in this study revealed that the grapevine viruses present in this area are diverse, indicating that they may have been introduced from different sources. Our findings stress the need for improving the sanitary status of planting materials to avoid the introduction and dissemination of viruses to vineyards in this important wine-producing region of New England.

A Fig Deal: A Global Look at Fig Mosaic Disease and its Putative Associates.

Fig mosaic disease (FMD) is a complex viral disease with which 12 viruses, including a confirmed causal agent, fig mosaic emaravirus (FMV), and three viroids are associated worldwide. FMD was first described in California in the early 1930s. Symptoms include foliar chlorosis, deformation, and mosaic patterns. FMD is disseminated by vegetative propagation, seed transmission, and vectors, including a mite, Aceria ficus. Management of the disease in fig orchards relies on scouting and elimination of infected trees. In this review, we focus on the distribution of the FMD-associated viruses and viroids by summarizing worldwide surveys and their genome structure. We also determined the full-length sequence of FMV and fig badnavirus 1 (FBV-1) isolates from Connecticut and compared the virus and viroid sequences from fig isolates. We suggest important areas of research including determining the potential synergistic effect of multiple viruses, elucidating the full-length genome sequence of each associated virus, and relating virus titer to phenotypic changes in Ficus carica.

Nematicidal potential of essential oils of Ageratum fastigiatum, Callistemon viminalis and Schinus terebinthifolius / Potencial nematicida de óleos essenciais de Ageratum fastigiatum, Callistemon viminalis e Schinus terebinthifolius

Some essential oils are rich in nematicidal compounds and can be used for the management of plant-parasitic nematodes. Laboratory and field studies aiming to evaluate the efficiency of this compounds are necessary. The objective of this research was to assess the nematicidal potential of essential oils from leaves of Ageratum fastigiatum and Callistemon viminalis, and green and mature fruits of Schinus terebinthifolius on the root-knot nematode Meloidogyne javanica. In laboratory, the essential oil of S. terebinthifolius green fruits reduced hatching by more than 80% and increased juvenile mortality by 300% when compared to Tween 20 + water. In the field, none of the essential oils controlled M. javanica in lettuce. In conclusion, the essential oil of S. terebinthifolius green fruits reduces the egg hatching and kills J2 of M. javanica in laboratory. In an infested field with an average of 555 J2/100 cm3 of soil, the application of the essential oils of S. terebinthifolius, C. viminalis and A. fastigiatum does not control M. javanica in lettuce.

Alguns óleos essenciais são ricos em compostos nematicidas e poderiam ser usados no manejo de fitonematoides. Estudos laboratoriais e de campo que visam avaliar a eficiência desses compostos são necessários. O objetivo desta pesquisa foi avaliar o potencial nematicida de óleos essenciais de folhas de Ageratum fastigiatum e Callistemon viminalis e frutos verdes e maduros de Schinus terebinthifolius sobre o nematoide de galhas Meloidogyne javanica. Em laboratório, o óleo essencial de frutos verdes de S. terebinthifolius reduziu mais de 80% a eclosão e aumentou em 300% a mortalidade de juvenis em comparação com Tween 20 + água. No campo, nenhum óleo essencial controlou M. javanica em alface. Em conclusão, o óleo de frutos verdes de S. terebinthifolius reduz a eclosão e mata J2 de M. javanica em laboratório. Em campo com infestação média de 555 J2/100 cm3 de solo, a aplicação dos óleos essenciais de S. terebinthifolius, C. viminalis e A. fastigiatum não controla M. javanica em alface.

Survival of Pochonia chlamydosporia on the soil surface after different exposure intervals at ambient conditions / Supervivencia de Pochonia chlamydosporia en la superficie del suelo después de diferentes intervalos de exposición a condiciones ambientales

Background. Exposure of the nematophagous fungus Pochonia chlamydosporia to solar radiation and elevated temperatures before being incorporated into the soil can reduce its survival and efficiency as biocontrol agent. Aims. A field experiment was carried out to assess the effect of the exposure period on the viability of P. chlamydosporia applied on the soil surface. Methods. A commercial bionematicide based on P. chlamydosporia was sprayed on soil, and soil samples were collected before and at 0, 30, 60, 90, 120, and 150 min after fungal application. Relative humidity (RH), the irradiance (IR), air temperature (AT), and soil temperature (ST) were recorded. The number of P. chlamydosporia colony forming units (CFUs) was evaluated after 20 days of incubation. Results. P. chlamydosporia survival decreased over the time of exposure on the soil surface. Overall, the number of CFUs decreased by more than 90% at 150min after application. Exposure to RH ≥61%, ST and AT between 25-35°C and 19-29°C, and IR between 1172 and 2126μmol of photons m−2s−1 induced a negative exponential effect on the survival of the fungus over the time. Conclusions. Exposure to climatic conditions on the soil surface reduces P. chlamydosporia viability (AU)

Antecedentes. La exposición del hongo nematófago Pochonia chlamydosporia a la radiación solar y la temperatura elevada antes de ser incorporado al suelo puede reducir su supervivencia y eficiencia como agente de biocontrol. Objetivos. Se realizó un experimento de campo para evaluar el efecto del período de exposición a condiciones ambientales sobre la viabilidad de P. chlamydosporia en la superficie del suelo. Métodos. Se pulverizó sobre el suelo un bionematicida comercial hecho a base de P. chlamydosporia y se recogieron muestras de suelo antes y después de 0, 30, 60, 90, 120 y 150min tras la aplicación del hongo. Se registraron la humedad relativa (HR), la irradiación (IR), la temperatura del aire (TA) y la temperatura del suelo (TS). Se evaluó el número de unidades formadoras de colonias (UFC) de P. chlamydosporia después de 20 días de incubación. Resultados. La supervivencia de P. chlamydosporia disminuyó durante el tiempo de exposición en la superficie del suelo. En general, el número de UFC disminuyó en más de un 90% a los 150min después de la aplicación. La exposición a HR≥61%, TS y TA entre 25-35°C y 19-29°C, e IR entre 1.172 y 2.126μmol de fotones m−2 s−1 indujo un efecto exponencial negativo en la supervivencia del hongo. Conclusiones. La exposición a las condiciones climáticas en la superficie del suelo reduce la viabilidad de P. chlamydosporia (AU)

Survival of Pochonia chlamydosporia on the soil surface after different exposure intervals at ambient conditions.

BACKGROUND: Exposure of the nematophagous fungus Pochonia chlamydosporia to solar radiation and elevated temperatures before being incorporated into the soil can reduce its survival and efficiency as biocontrol agent. AIMS: A field experiment was carried out to assess the effect of the exposure period on the viability of P. chlamydosporia applied on the soil surface. METHODS: A commercial bionematicide based on P. chlamydosporia was sprayed on soil, and soil samples were collected before and at 0, 30, 60, 90, 120, and 150min after fungal application. Relative humidity (RH), the irradiance (IR), air temperature (AT), and soil temperature (ST) were recorded. The number of P. chlamydosporia colony forming units (CFUs) was evaluated after 20 days of incubation. RESULTS: P. chlamydosporia survival decreased over the time of exposure on the soil surface. Overall, the number of CFUs decreased by more than 90% at 150min after application. Exposure to RH ≥61%, ST and AT between 25-35°C and 19-29°C, and IR between 1172 and 2126µmol of photons m-2s-1 induced a negative exponential effect on the survival of the fungus over the time. CONCLUSIONS: Exposure to climatic conditions on the soil surface reduces P. chlamydosporia viability.