BYGL Disease Digest July 17, 2008 PLANT DIAGNOSTIC ACADEMY (PDA) DISEASE NOTES
| PLANT DIAGNOSTIC ACADEMY (PDA) DISEASE NOTES |
 |
 |
 |
|
Last Wednesday-Friday, OSU’s ENLT Team and Woodland Stewards Team conducted a three day Plant Diagnostic Academy (PDA) at the Ohio Agricultural Research and Development Center (OARDC) and Secrest Arboretum in Wooster, Ohio. Here is our blight and blister report. * OAK LEAF BLISTER was going strong on red oaks at Secrest Arboretum. Leaves had raised, reddish-brown 1/3-1/2" blisters on upper leaf surfaces, making some of the foliage look distorted, but causing little overall oak health problems.* GUIGNARDIA LEAF BLOTCH OF AESCULUS was going strong on horsechestnuts and buckeyes, especially on lower leaves where there was less air movement and thus more potential for high relative humidity and leaf moisture periods long enough for fungal infections. Predictably, common horsechestnut and some of the horsechestnut-buckeye hybrids were most affected by this leaf blotch disease that results in brownish-red leaf blotches (often with yellow halos on the lesion edges). Red buckeye and bottlebrush buckeyes exhibited little to no disease incidence. * Other disease notes from Secrest and the PDA included: light early incidence of POWDERY MILDEW OF MAGNOLIA resulting in some white mycelial growth of the fungus and the start of reddish to grayish leaf discoloration and desiccation; plenty of ROSE BLACK SPOT; some PHYLLOSTICTA LEAF SPOT OF MAPLE (tiny little brown lesions with red borders); and CEDAR HAWTORN RUST in which the fungus had not emerged yet from the undersides of the leaves, where fungal spores then blow back to the juniper hosts over the next few months. |
| Last Updated ( Thursday, 17 July 2008 21:37 ) |
