Comparative Performance of Fungicides in Management of Phytophthora Root Rot on Boxwood
Nursery growers rely on fungicides to manage root rot disease of boxwood caused by Phytophthora nicotianae and P. cinnamomi. Repeated use of the same fungicide may lead to the fungicide resistance. In this study, fungicides pyraclostrobin + cyazofamid (Empress + Segway), ametoctradin + dimethomorph...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
American Society for Horticultural Science (ASHS)
2023-07-01
|
| Series: | HortScience |
| Subjects: | |
| Online Access: | https://journals.ashs.org/hortsci/view/journals/hortsci/58/8/article-p893.xml |
| _version_ | 1797754290548244480 |
|---|---|
| author | Madhav Parajuli Sandhya Neupane Prabha Liyanapathiranage Fulya Baysal-Gurel |
| author_facet | Madhav Parajuli Sandhya Neupane Prabha Liyanapathiranage Fulya Baysal-Gurel |
| author_sort | Madhav Parajuli |
| collection | DOAJ |
| description | Nursery growers rely on fungicides to manage root rot disease of boxwood caused by Phytophthora nicotianae and P. cinnamomi. Repeated use of the same fungicide may lead to the fungicide resistance. In this study, fungicides pyraclostrobin + cyazofamid (Empress + Segway), ametoctradin + dimethomorph (Orvego), ametoctradin + dimethomorph alternated with pyraclostrobin (Orvego alt Empress), ametoctradin + dimethomorph alternated with fluxapyroxad + pyraclostrobin (Orvego alt Orkestra), and oxathiapiprolin (Segovis) were evaluated for their efficacy in managing Phytophthora root rot under greenhouse conditions in Tennessee. One-year-old container-grown boxwood ‘Green Velvet’ plants were inoculated with P. nicotianae or P. cinnamomi. The first applications of fungicide treatments were made preventatively as a drench 48 h before pathogen inoculation. Following inoculation, four applications of fungicide treatments were performed on a 14-day intervals. Initial and final plant height and width were measured. Total plant fresh weight and root fresh weight were measured at the end of the trials, and plants were evaluated for root rot severity (0% to 100% roots affected) and pathogen recovery. All fungicides significantly reduced root rot severity and pathogen recovery of P. nicotianae and P. cinnamomi. Ametoctradin + dimethomorph alternated with pyraclostrobin (Orvego alt Empress) provided similar protection against P. cinnamomi to that of a single application of ametoctradin + dimethomorph (Orvego) or oxathiapiprolin (Segovis). For P. nicotianae, ametoctradin + dimethomorph alternated with pyraclostrobin + fluzapyroxad (Orvego alt Orkestra) was found to be as effective as a single application of either ametoctradin + dimethomorph (Orvego) or oxathiapiprolin (Segovis) in one of the two trials. Effects of fungicides on plant growth such as height, width, total, and root fresh weight were not significant. These findings will be useful to nursery growers in selecting the right fungicide program for the management of root rot disease of boxwood caused by P. nicotianae and P. cinnamomi. |
| first_indexed | 2024-03-12T17:31:27Z |
| format | Article |
| id | doaj.art-48488505a2064d56a6293d354edbdab7 |
| institution | Directory Open Access Journal |
| issn | 2327-9834 |
| language | English |
| last_indexed | 2024-03-12T17:31:27Z |
| publishDate | 2023-07-01 |
| publisher | American Society for Horticultural Science (ASHS) |
| record_format | Article |
| series | HortScience |
| spelling | doaj.art-48488505a2064d56a6293d354edbdab72023-08-04T19:30:18ZengAmerican Society for Horticultural Science (ASHS)HortScience2327-98342023-07-01588https://doi.org/10.21273/HORTSCI17227-23Comparative Performance of Fungicides in Management of Phytophthora Root Rot on Boxwood Madhav Parajuli0Sandhya Neupane1Prabha Liyanapathiranage2Fulya Baysal-Gurel3Tennessee State UniversityTennessee State UniversityTennessee State UniversityTennessee State UniversityNursery growers rely on fungicides to manage root rot disease of boxwood caused by Phytophthora nicotianae and P. cinnamomi. Repeated use of the same fungicide may lead to the fungicide resistance. In this study, fungicides pyraclostrobin + cyazofamid (Empress + Segway), ametoctradin + dimethomorph (Orvego), ametoctradin + dimethomorph alternated with pyraclostrobin (Orvego alt Empress), ametoctradin + dimethomorph alternated with fluxapyroxad + pyraclostrobin (Orvego alt Orkestra), and oxathiapiprolin (Segovis) were evaluated for their efficacy in managing Phytophthora root rot under greenhouse conditions in Tennessee. One-year-old container-grown boxwood ‘Green Velvet’ plants were inoculated with P. nicotianae or P. cinnamomi. The first applications of fungicide treatments were made preventatively as a drench 48 h before pathogen inoculation. Following inoculation, four applications of fungicide treatments were performed on a 14-day intervals. Initial and final plant height and width were measured. Total plant fresh weight and root fresh weight were measured at the end of the trials, and plants were evaluated for root rot severity (0% to 100% roots affected) and pathogen recovery. All fungicides significantly reduced root rot severity and pathogen recovery of P. nicotianae and P. cinnamomi. Ametoctradin + dimethomorph alternated with pyraclostrobin (Orvego alt Empress) provided similar protection against P. cinnamomi to that of a single application of ametoctradin + dimethomorph (Orvego) or oxathiapiprolin (Segovis). For P. nicotianae, ametoctradin + dimethomorph alternated with pyraclostrobin + fluzapyroxad (Orvego alt Orkestra) was found to be as effective as a single application of either ametoctradin + dimethomorph (Orvego) or oxathiapiprolin (Segovis) in one of the two trials. Effects of fungicides on plant growth such as height, width, total, and root fresh weight were not significant. These findings will be useful to nursery growers in selecting the right fungicide program for the management of root rot disease of boxwood caused by P. nicotianae and P. cinnamomi.https://journals.ashs.org/hortsci/view/journals/hortsci/58/8/article-p893.xmlbuxus spp.chemical controlphytophthora spp.soilborne diseasewoody ornamentals |
| spellingShingle | Madhav Parajuli Sandhya Neupane Prabha Liyanapathiranage Fulya Baysal-Gurel Comparative Performance of Fungicides in Management of Phytophthora Root Rot on Boxwood HortScience buxus spp. chemical control phytophthora spp. soilborne disease woody ornamentals |
| title | Comparative Performance of Fungicides in Management of Phytophthora Root Rot on Boxwood |
| title_full | Comparative Performance of Fungicides in Management of Phytophthora Root Rot on Boxwood |
| title_fullStr | Comparative Performance of Fungicides in Management of Phytophthora Root Rot on Boxwood |
| title_full_unstemmed | Comparative Performance of Fungicides in Management of Phytophthora Root Rot on Boxwood |
| title_short | Comparative Performance of Fungicides in Management of Phytophthora Root Rot on Boxwood |
| title_sort | comparative performance of fungicides in management of phytophthora root rot on boxwood |
| topic | buxus spp. chemical control phytophthora spp. soilborne disease woody ornamentals |
| url | https://journals.ashs.org/hortsci/view/journals/hortsci/58/8/article-p893.xml |
| work_keys_str_mv | AT madhavparajuli comparativeperformanceoffungicidesinmanagementofphytophthorarootrotonboxwood AT sandhyaneupane comparativeperformanceoffungicidesinmanagementofphytophthorarootrotonboxwood AT prabhaliyanapathiranage comparativeperformanceoffungicidesinmanagementofphytophthorarootrotonboxwood AT fulyabaysalgurel comparativeperformanceoffungicidesinmanagementofphytophthorarootrotonboxwood |