The ARS is funding a three year study at the University of Tennessee. Objectives include trying to develop an ELISA test and studying the spread within garden conditions of a garden composed solely of a single cultivar (way out in the country where there are no rose gardens down wind). They have as RRD source plants severely infected plants of the same cultivar. I haven't heard the results of the first year, yet. ----------------- re R. rugosa. Early on, in the garden we followed at Lincoln Memorial University, there was also a plantings of many Pink Grootendorsts near a building that had been the Dairy. They did not get sick for several years as the modern roses planted immediately downwind of multiflora-rich field whose plants were at least 30%infected with RRD. At one time we found some strange swellings on the PG canes, and they made the rounds of a number of Plant Pathologists; no idea what their problem was, but it was just the swelling. Then five or six years in, a plant got two canes that were even more thorny, whose new growth spiraled, whose leaf margins were different and whose blooms were messed up badly. Now I wish I had made scans of the canes, but we were busy with other plases of following the disease as it spread. The problem with the declarations that certain roses don't get RRD is that no one has ever taken the spectrum of all roses species and planted them in different USDA zones and left them in high disease pressure areas for a five to seven year period. What I've seen this winter, when where I live is zone 7 low temperatures, is that the plants with RRD have grown through winter....at least the parts with RRD have. The uninfected canes have gone semidormant. There's so much that we don't know. Here is a link that might be useful: Rose Rosette E-book

The following was stated: “Suspect. Treat plants with RRD with hydrogen peroxide. According to members of the RRD Task Force there is no credible data to show that hydrogen peroxide will help a plant infected with RRD. In fact, hydrogen peroxide has the ability to damage plants.” ———————————— H.Kuska Comment: Concerning the "credible data" part the above is strictly correct, but there is credible data that externally applied hydrogen peroxide can contribute to the plant's ability to fight viruses in other plants. But before we look at that part, lets get rid of the "has the ability to damage plants". No reference(s) was/were given. Of course hydrogen peroxide in too high a concentration can damage plants. A recent field of study concerns the chemistry of "RNA silencing pathway in the plant defense against viruses" as a means that plants utilize to defend themselves against viruses. Two chemicals that are easily available to the home gardener that have been shown by controlled published research to instigate the RNA silencing pathway in the plant defense against viruses are aspirin and hydrogen peroxide. ---------------------------------------------------------------------------------------- I will give two examples for hydrogen peroxide. 1) http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0076090 Title: "The Role of Hydrogen Peroxide and Nitric Oxide in the Induction of Plant-Encoded RNA-Dependent RNA Polymerase 1 in the Basal Defense against Tobacco Mosaic Virus" Published in 2013. This is a very complete (and complex) scientific study so I will just extract the following: " Pretreatment with H2O2 or SNP significantly decreased TMV susceptibility, and these leaves did not show any visible systemic symptoms." In the Discussion section the following appears: "This signaling pathway may be a general pathway common to plants." ----------------------------------------------------------------------------- Example 2. http://www.akademiai.com/doi/abs/10.1556/APhyt.46.2011.1.1 Title: " Inhibition of virus replication and symptom expression by reactive oxygen species in tobacco infected with Tobacco mosaic virus " “In spite of the enormous information from research on genetics of plant disease resistance, the question still remains unresolved: what is directly inhibiting or killing pathogens and suppressing symptoms in resistant plants? This is particularly true for resistance to viral infections. Here we show that externally applied reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) or ROS-producing (O 2·− [superoxide] and H2O2) chemical systems infiltrated into tobacco leaves 2 hours after inoculation suppress replication of Tobacco mosaicvirus (TMV) in the susceptible Samsun (nn) cultivar. This was determined by a biological and a real-time PCR method. Infiltration of leaves of the resistant Xanthi (NN) cultivar with the ROS-producing chemicals and H2O2 significantly suppressed local necrotic lesions (i.e. the hypersensitive response) after inoculation of tobacco leaves with TMV. Accordingly, an early accumulation or external application of ROS, such as O 2·− and H2O2, in tobacco may contribute to the development of resistance to TMV infection.”

Sorry for the delayed response. It has been a very hectic past few days! Dumb question. Is RRD contagious? Meaning if I try the wait and see approach (by removing only the impacted canes instead of digging up the whole plant) with the roses who don't seem to have it as bad yet.....will I take a risk that somehow the RRD could get transmitted to the roses who don't have it? I would hate to lose any of the seemingly healthy roses by doing this. Moving forward, is there anything I can do to lessen the chances of the roses getting RRD? This summer Japanese beetles have been widespread in this area. Honestly, I can't ever remember them being this bad before now...or ever even seeing them really. I know of several other people who have knockout roses here and everyone is having the same problem with the Japanese beetles feasting on them. So as bad as it may sound, I can take some solace in knowing it is not just my roses that are getting hit. Is there anything I can spray on the roses to prevent Japanese beetles from attacking them?

I added what I had on Friday. I can see the addition, but it was never recorded in the number of posts???? Title: "First report of rose rosette disease caused by Rose rosette virus on Knock Out roses in Louisiana." Author(s) : Singh, R.; Valverde, R.; Cook, M.; Owings, A. Author Affiliation : Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA. Author Email : rsingh@agcenter.lsu.edu Journal article : Plant Health Progress 2016 No.August pp.PHP-BR-16-0022 ref.1 Abstract : " To the authors' knowledge, this is the first report of rose rosette disease caused by Rose rosette virus on Knock Out roses in Louisiana. It is difficult to assess the total value of roses in Louisiana but this disease has the potential to negatively impact the thriving rose industry in the state."