Potato late blight: in vitro studies and development of a fungicide programme for disease control
| MSI00P3392 | |
| Ganoo, S. Saumtally, S. | |
| Potato late blight: in vitro studies and development of a fungicide programme for disease control | |
| Adipala, E., Nampala, P. and Osiru, M. (eds), Potatoes for poverty alleviation: Proceedings of the 5th Triennial Conference of the African Potato Association, 29 May - 2 June 2000, Kampala, Uganda | |
| Book chapter | |
| 2000 | |
| p.309-315 | |
| Kampala: African Potato Association | |
| En | |
| En | |
| Studies on the culture of local isolates of Phytophthora infestans were initiated in August 1999. Isolates were collected from potato, tomato and Solanum nigrum, out of which 9 were successfully grown on pea agar amended with antimicrobial products. The reaction of potato varieties to the disease was determined in vitro using the floating leaf-disks method and comparison with field evaluation showed that a good correlation existed between the two methods with a few exceptions. Metalaxyl resistance of five isolates was assessed by radial growth on metalaxyl-amended pea agar. Variation in metalaxyl sensitivity was observed among the isolates, indicating the possible existence of metalaxyl resistant strains. Field trials were conducted to identify fungicides to be used in order to avoid the over-use of metalaxyl, which could lead to the development of metalaxyl-resistant strains. Based on the reaction to late blight of various cultivars planted in Mauritius and in relation to climatic zones, spraying schedules were devised whereby the use of metalaxyl + mancozeb or chlorothalonil was limited to four initial sprays. Thereafter, non-metalaxyl products could be used. When grown in the humid and subhumid zones, phenylamide fungicides were not necessary, except under conditions favourable to late blight development. It is expected that such a strategy will ensure the effective utilization of metalaxyl in the medium and long term. | |
| Potatoes Isolation metalaxyl resistance Phytophthora infestans Diseases Fungicides | |
| Mauritius | |
| Potatoes | |
| Diseases | |
| 2000-06-22 | |
| En | |
| Path | |
| CAT | |
| Path |