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| | Rose Black Spot - Plant and Pest Digital Library Project, Purdue University, West Lafayette, Indiana, USA |
 | | Black spot, caused by the fungus Diplocarpon rosae, is the major foliar disease of roses in Indiana. |
 | | It is possible for rose disease resistance to break down due to the fl spot fungus adapting to the plant’s resistance, so resistance can be lost. |
 | | He explained that there are several reasons why these cultivars now fail to resist fl spot, including: low disease pressure in the initial tests, inaccurate reporting of results, changes in the fl spot fungus allowing it to overcome resistance, or very high disease pressure in locations where these cultivars now fail. |
| www.ppdl.org /dd/id/rose_black_spot.html (640 words) |
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