Development of Crape Myrtle Germplasm OF with Resistance to Cercospora Leaf Spot (CLS) and Powdery Mildew
Southern Horticultural Research
2011 Annual Report
1a.Objectives (from AD-416)
To screen crape myrtle germplasm for host plant resistance to Cercospora Leaf Spot (CLS) and powdery mildew. Emphasis will be placed on maintaining germplasm under ambient field conditions and other horticultural necessities.
1b.Approach (from AD-416)
Crape myrtle controlled crosses and commerical clones will be placed at the cooperator's location and will be screened for CLS and powdery mildew. Evaluations will be made by the cooperator and by ARS scientists throughout the evaluation season each year. Germplasm with host plant resistance will be tested further in subsequent experiments.
Screening for resistance to powdery mildew and Cercospora Leaf Spot (CLS) continues on the elite 110 seedlings selected from 2,000 original crape myrtle seedlings. Selections are rated for disease symptoms at least two times during the growing season. One to three selections may be made during the 2011 growing season as potential candidates for release. The 2010 season had a dry spring which delayed flowering. Little powdery mildew was observed on other crape myrtle clones growing in proximity to the test area but CLS pressure in the fall was severe. Final selections will be selected based on 4 years data after the 2011 growing season. The ADODR or his representative meets regularly with the cooperating scientist at Auburn, and these meetings included 2 site visits during 2011.