FLORIGENE PTY LTD 

1 PARK DRIVE 

BUNDOORA 

VICTORIA 3083 

AUSTRALIA 

TEL +61 3 9243 3800 

FAX +61 3 9243 3888 

 

John Cordts 

USDA 

Unit 147 4700 River Rd 

Riverdale MD 20737-1236 

USA 

DATE: 23/12/09 

Subject: Petition number 08-315-01p for a determination of non-regulated status 

for Rosa X hybrida varieties IFD-52401-4 and IFD-52901-9 – ADDENDUM 1. 

Dear John, 

As requested Florigene is submitting “Addendum 1: pests and disease for roses” to add to 

petition 08-315-01p. This addendum outlines some of the common pest and diseases 

found in roses. It also includes information from our growers in California and Colombia 

stating that the two transgenic lines included in the petition are normal with regard to 

susceptibility and control.

This addendum contains no CBI information. 

Kind Regards, 

Katherine Terdich 

Regulatory Affairs 
ADDENDUM 1: PEST AND DISEASE ISSUES FOR ROSES 

Roses like all plants can be affected by a variety of pests and diseases. Commercial 

production of plants free of pests and disease requires frequent observations and strategic 

planning. Prevention is essential for good disease control. Since the 1980’s all 

commercial growers use integrated pest management (IPM) systems to control pests and 

diseases. IPM forecasts conditions which are favourable for disease epidemics and 

utilises sprays only when necessary. 

The most widely distributed fungal disease of roses is Powdery Mildew. Powdery 

Mildew is caused by the fungus Podosphaera pannosa. It usually begins to develop on 

young stem tissues, especially at the base of the thorns. The fungus can also attack leaves 

and flowers leading to poor growth and flowers of poor quality. Control of the fungus is 

achieved by protective sprays such as Benomyl, Captan, and Triforine. Other preventive 

measures include; removal of infected shoots and lowering night humidity (in glasshouse 

conditions). 

Table 1 outlines a variety of other pest and diseases that can affect roses and describes 

treatment. 

Table 1: Some common pest and diseases of Roses and the recommended treatment 

(Horst, 1995; Stroom et al., 2008; Roberts et al, 2003) 

Pest/disease Treatment 

Two spotted mite ETI miticides, fenpyroximate (Dynamite) and tebufenpyrad 

(Pyranica) for adult stages and Ovicides, clofentezine 

(Apollo) for eggs. Introduce predatory mite Phytoseiulus 

persimilis

Downy mildew Lowering humidity and keeping temperature constant. 

Removal of infected tissues and spray with fungicidal sprays 

such as Metiram, Fosetyl-aluminium or Propamocarb. 

Rust Removal of infected tissues and spray with fungicidal sprays 

such as Thiram, Maneb or Zineb at ten day intervals 

Verticullium wilt Sterilise soil before planting 

Botrytis blight Lowering humidity and keeping temperature constant. 

Removal of infected tissues and spray with fungicidal sprays 

such as Clorthalonil or Fenhexamide 

Black spot (minor problem 

in glasshouse grown roses) 

Removal of infected tissues and spray with Mancozeb, 

Ziram, Triforine, Dodine or Kresoxim-methyl. 

Aphids Removing them by hand, high-pressure watering wands 

especially designed for insect control, release of natural 

predators and parasites, and/or a variety of organic and 

synthetic pesticides. 

Japanese bettle, Rose 

chafers 

Hand pick if infestation is light. The insecticides carbaryl 

(Sevin), acephate (Orthene), diazinon, and chlorpyrifos 

(Dursban) control these beetles. 

Viruses such as Rose 

Mosaic Virus (RMV) 

Ensure certified virus free rootstocks (if grafting). Destroy 

plants when infected. If available, heat treatment and 

meristem tip culture may be used to obtain clean material. 
The following paragraphs are excerpts from an email from Jackson and Perkins noting 

their specific experience with pest and diseases when dealing with the transgenic rose 

lines IFD-52401-4 and IFD-52901-9. 

Jackson and Perkins Wholesale, Inc. has grown the Florigene transgenic lines at the 

Somis, California facility for the past 4 years. These cultivars have grown normally in 

all respects. When grown under cover they suffer from 3 different pests, as do all 

commercially grown cut roses in California. These roses can become infected with the 

two spotted spider mite (Tetranychus urticae), with powder mildew (Podosphaera 

pannosa) and with downy mildew (Peronospora sparsa). These are ubiquitous pests 

throughout all of the United States and infect roses anywhere roses are grown 

commercially. All three pests can be controlled using common treatments and 

conventional protocols. These transgenic lines are completely normal with regard to 

susceptibility and control. 

 

These three pests are most common when the roses are most actively growing. Mites 

prefer the warmth of long summer days. At the Somis location we treat for this pest 

usually 3-5 times a year. Powdery mildew is common when the seasons change from 

winter to spring and from summer to fall. The large temperature change from day to 

night encourages the conditions necessary for disease development. By properly 

controlling the greenhouse environment you can eliminate or nearly eliminate this 

disease. We spray for it 2 or 3 times a year. Downy mildew is mostly a fall to winter 

disease that likes cool moist conditions. It is a rare event in a greenhouse. We only 

spray for this occasionally - perhaps once a year. 

In Colombia, transgenic rose lines IFD-52401-4 and IFD-52901-9 have been grown 

within a very large rose growing facility, adjacent to both the parental control and other 

commercial rose varieties. Under these conditions, pest and disease control measures are 

more intense as commercial flower must be completely free of disease and insect damage, 

as flowers are intended for export. The crop, including the transgenic lines, was 

chemically treated on a weekly basis, with treatments including Vertimec, Teldor and 

Previcur. The grower noted that the transgenic and parental controls were susceptible to 

Mildew, but that there was no difference between the transgenic lines and parental 

control. 

References

Horst, R.K. 1995. Compendium of rose diseases. The American Phytopathological 

Society Press (APS press), Minnesota, USA. 

Roberts, A.V., Debener, T. and Gudin, S. 2003. Encyclopedia of rose science. Volume 

1. Elsevier Academic Press, San Diego, USA. 

Stroom, K., Fetzer, J. and Krischik, V. 2008. Insect pests of roses. University of 

Minnesota. http://www.extension.umn.edu/distribution/horticulture/DG6953.html