In vitro resistance of Phytophthora infestans to metalaxyl and control of late blight using non-phenylamide fungicides
| MSI00P3611 | |
| Ganoo, S. Saumtally, S. | |
| In vitro resistance of Phytophthora infestans to metalaxyl and control of late blight using non-phenylamide fungicides | |
| Programme, Abstracts of papers: Agricultural policy, sustainable crop production and poverty alleviation in Africa: 5th Biennial conference of the African Crop Science Society, Le Meridien Eko Hotel, Victoria Island, Lagos, Nigeria, October 21-26, 2001 | |
| 2001 | |
| p.43 | |
| 978-006-163-0 | |
| African Crop Science Society | |
| Abstract only | |
| En | |
| En | |
| Strains of Phytophthora infestans were collected from potato, tomato and Solanum nigum in 1999-2000 and grown on pea agar supplemented with antimicrobial compounds. Metalaxyl resistance of strains was assessed in vitro by measuring radial growth of the colony on pea agar containing metalaxyl. Variation in metalaxyl sensitivity was observed among the strains. Strain 3609 was highly sensitive and did not grow in the presence of the fungicide. the remaining nine strains were affected to various extents. Although they all grew less than the control at 5 ppm metalaxyl, six strains (3605, 3607, 3608, 3610, 3635, and 3638) grew more than 40 per cent of the control By convention, they can be considered as resistant to the fungicide. Field trials were conducted to identify fungicides that could be substituted to avoid the overuse of metalaxyl, which could lead to a build-up of metalaxyl-resistant P. infestans strains. Fungicides Bion (acibenzolar-S-methyl), flint (trifloxystrobin), Akomin (potassium phosphonate), Melody Duo (iprovalicarb + propineb) followed by Dithan M45 (mancozeb), and Dithane M 45 only, were compared to the standard treatment of Ridomil Gold (metalaxyl + mancozeb) followed by Dithane M45. Melody Duo followed by Dithane M45 was found to be as effective as the standard treatment. light incidence was 0.1 per cent with both treatments compared to 100 per cent in untreated plots 11 weeks after planting. The other fungicides did not provide sufficient control of the disease. Melody Duo followed by Dithane M45 appears to be an appropriate non-phenylamide of the disease alternative against late blight in a strategy to limit the development of metalaxyl-resistant strains of P. infestans. | |
| Potatoes tomatoes Solanum nigrum Isolation metalaxyl resistance Phytophthora infestans Diseases Fungicides | |
| Mauritius | |
| Potatoes | |
| Diseases | |
| 2001-11-07 | |
| En | |
| Path | |
| cat | |
| Path |