Table of Contents
A Study of Black Spot Resistance in the Rose, A Rating System to Characterize a Variety's Resistance, Cultivars With High Resistance, and a Modern Non-Toxic Bacterium Spray Program for Controlling Black Spot.
Text of Presentation submitted to The American Rose Society and the National Chairperson of the American Rose Society's Consulting Rosarians Committee.
January, 1997
These are Preliminary Results Only
by
Norman Rose
7128 Cedar
Prairie Village, Kansas 66208
Copyright 1997
Introduction
Introduction
Introduction
Introduction
Introduction
Introduction
The disease known as black spot has probably done more to discourage potential rose gardeners than any other factor. Consulting Rosarians should familiarize themselves and recommend those cultivars that require little or no sophisticated spray programs in order to control black spot and yet will reward the grower with expected delights such as hardiness, vigor, fragrance and beauty. These results are especially important to the beginner or novice rose grower. Without these beginners, Rose Societies cannot grow and flourish.
This fungal disease is caused by the pathogen Marssonina rosae or its sexual stage which goes by the name of Diplocarpon rosae. It is a two cell spore that is not visible without the aid of a microscope1 This disease is characterized by black irregular lesions appearing to be on the leaf surface, however occuring under the surface of the leaf. The lower leaves are almost always the first to be infected unless the cultivar is in close proximity to a structure such as the wall of a house or a trellis, in which case the upper leaves can show first infection. These spores over-winter in infected leaves, canes, or on rough surfaces. They do not over-winter in the soil.7 These spores have no means of self propulsion and are not dispersed by the wind. Splashing water, resulting from rainfall or sprinklers, generally provides a means of transportation for the spore, however it is thought that some spores can hitch a ride on the back of a sticky insect.
The following research has been initiated for three main reasons. The first, is to promote the Texas A&M rating system that characterizes a variety's resistance to black spot. This rating system was developed and used as a result of the existence of the Robert E. Basye Endowed Chair in Rose Genetics which is more fully defined and described at the end of this paper. The second is to identify those cultivars that have a high degree of resistance to black spot. The third is to develop and promote a non-toxic spray program that is user friendly and yet has the ability to kill the black spot fungus.
Materials and Methods
An accurate and consistent rating system for characterizing a cultivars resistance to black spot has been developed and placed in use by Texas A&M University located in College Station, Texas. This system consists of a black spot rating and a defoliation rating and is set forth in figure 1. This approach is part of an ongoing research program designed to identify resistance in currently existing cultivars and to develop breeding stock that will assist rose hybridizers in producing black spot resistant varieties. This field study, conducted at Texas A&M University, is more fully described in a paper written by William Black, David H. Byrne, and H. Brent Pemberton and entitled, "Field Study of Black Spot Resistance in the Rose". These evaluations of black spot resistance are best performed in early to mid summer. A black spot rating of 0 to 2.5 was categorized as high resistance. A rating from 2.5 to 5.0 was categorized as moderate resistance and up to 7.5 points was considered low resistance. Above 7.5, a variety is considered susceptible to black spot. A low black spot rating indicates good resistance, however, a defoliation rating is used to augment the categorization. A variety with a defoliation rating more than 2.5 points but less than 5.0 points higher than its black spot rating was dropped a category. A defoliation rating between 5.0 and 7.5 moves a variety two categories and a defoliation rating of 7.5 or greater would drop a variety three categories. This methodology was used to compensate for varieties that defoliate quickly after infection and therefore show lesions only briefly. An example of this is the cultivar All That Jazz which has a low black spot rating of 1.50, but a defoliation rating of 6.25. Using just the black spot rating alone would give the erroneous conclusion that this cultivar has high resistance. An opposite example would be the cultivar Morden Blush that has a BS Rating of 4.25 but a Defoliation Rating of only 1.75. In other words this rose will spot up to 42.5% of its leaves but will drop only 17.5% of them.
Black Spot Rating
(Percent infected leaflets on bush)
Defoliation Rating
(Percent leaves missing on existing stems)
0 = (0 -10%)
1 = (11 - 20%)
2 = (21 - 30%)
3 = (31 - 40%)
4 = (41 - 50%)
5 = (51 - 60%)
6 = (61 - 70%)
7 = (71 - 80%)
8 = (81 - 90%)
9 = (91 - 100%)
Figure 1
Two trials have been set up thus far at Texas A&M which included forty-five varieties in the first trial and seventy-eight varieties in the second trial. These included species and commercial material. The authors trial for black spot resistance, consisted of eighty-four cultivars located at his home in Prairie Village, Kansas which is a suburb of Kansas City. These cultivars received no spray of any kind throughout the year of 1996.
Two cultivars that are extemely vunerable to black spot were chosen by the author to receive a spray program, beginning in the second week of April, consisting of a weekly application of a soil based bacterium that is sold under the commercial name of Rose FloraTM. These cultivars were the species rose Rosa Foetida Persiana (Persian Yellow) and the grandiflora Spellcaster. Both of these cultivars become completely defoliated by mid summer if left unsprayed. Two hundred and one other cultivars in the authors garden received weekly sprayings of a triforine based spray. Early summer evaluations of the two spray programs compared to the next door neighbors unsprayed and badly infected roses (which were used as a control), indicated that the Rose Flora TM sprayed roses were equal to or better than those roses receiving the triforine based spray. Because of these results coupled with a laboratory report that indicated that Rose FloraTM did indeed kill the black spot fungus in vitro (in the laboratory) the author switched over to a spray program which consisted of weekly sprayings of Rose FloraTM mixed with a 3% solution of the anti-tanspirant WILT-PRUFR.
Discussion
Discussion
It seems reasonable that newcomers to rose cultivation should be introduced to varieties that are highly resistant to black spot and therefore are more likly to succeed. Some of these varieties will succeed and thrive even though they receive only a big dose of neglect! Cultivars that rely absolutely on a mature, experienced, toxic spray program should be avoided when recommendations are made to newcomers.
The existing system for rating disease resistance in the rose is totally inadequate, non-descriptive, deceptive, misleading, self-serving, ineffective, and worthless. I site as an example the book, Taylors Guide to Roses, Houghton Mifflin Company, Boston. In this book the author lists 64 Hybrid Tea roses. Sixty one of these hybrid teas are listed as "Disease Resistant". The rose First Prize is listed as "Disease prone; requires protection against black spot and mildew" and the rose Oregold is listed as "disease resistant but needs protection from black spot and mildew". The rose Sweet Surrender has no comment whatsoever. It is common knowledge that most of these hybrid teas will easily succumb to black spot if left unsprayed. Therefore, the term "Disease resistant" used in this context has no useful meaning when it comes to selecting roses that are likly to survive without a regular spray program. Thirty-eight of forty floribundas are listed as "disease resistant" and all twelve grandifloras are likewise listed as "Disease resistant". Of the forty eight shrub roses listed, all are listed as either "Disease resistant" or "Disease free". Most modern roses should be listed as "Chemically Dependent"! Figure 2 below is a scientific analysis of black spot resistance in various classes of roses.
Black Spot Resistance Among Classes of Roses3
Rose Class Resistant Intermediate Susceptible
Floribundas 7% 36% 57%
Grandifloras 0% 75% 25%
Hybrid Teas 10% 35% 55%
Shrub Roses 63% 26% 11%
Rugosa Hybrids 100% 0% 0%
Species/Hybrids 96% 0% 4%
Basye Roses 100% 0% 0%
Figure 2
Since only 7% of floribundas and only 10% of the hybrid teas are "resistant" to black spot (i.e. from 0 to 25% defoliation) it would behoove the consulting rosarian to seek out and identify these resistant varieties and strongly recommend them to newcomers. The shrub rose class offers a broader spectrum of good choices and many of these roses have characteristics of the more desirable hybrid teas and floribundas. A consultant making recommendations should rise above rose class prejudices and should consider the following:
1. Resistance to black spot 2. Hardiness
3. Vigor 4. Beauty
5. Fragrance
The consideration and implementation of the above attributes will determine the success or failure of a beginner or the effectiveness of a public garden.
It should be noted that wide and varied differences exist within any given class of roses. As an example the ARS designation of the rose Guy de Maupassant as a floribunda would tend to lead you to the conclusion that this is a rather short rose when in fact it is listed in the catalog as growing to 6 to 9 feet tall. Likewise, the rose Frederic Mistral is sold as a shrub and listed by the ARS as a Hybrid Tea. What really matters about this beautiful rose is that it is "especially resistant to black spot" and "Fragrance is out-of-this-world". Also the rose Mabel Stearns is sold as a hybrid tea and listed as a shurb. This rose has all the attributes of a hybrid tea plus the added benefits of extraordinary hardiness, fragrance and high resistance to black spot. Its blossoms are ideal for cutting, lasting up to 10 days. If you must call it a shrub rose, then it is a shrub rose with all the growth and flowering characteristics of a hybrid tea.
The active ingredient in Rose FloraTM is a soil based bacterium that is, in fact, a friendly non-toxic organic bacteria which is 100% environmentally safe for humans or pets. It is used to treat intestinal problems in humans, however what you will be purchasing is an agriculture grade and is not recommended for human consumption. No precautions need be taken when mixing or applying this product. It will not burn roots, branches, leaves or blossoms. Nor is it harmful to other flowers, fruits, vegetables or your herb garden. Since Rose FloraTM is a natural organic bacteria it is possible to kill it under perilous conditions. Some chemicals may contain ingredients that will kill off this bacteria. Chlorine is one such chemical, however the normal amount of chlorine found in most city water systems is acceptable. Rose FloraTM is compatible with other fungicides and most pesticides commonly used in the rose industry. It also works by accelerating the photosynthetic process. The millions of nitrogen fixing bacteria release high energy nutrients and supply essential nitrogen for optimun growth. It also rejuvenates and conditions the soil. The author reconstitutes one gallon, further reduces the concentration by 35 times (35 Gallons) and applies a portion of this diluted solution to layers of composting leaves and horse manure which will be used as a mulch (yields about one ton) for the rose beds, applied around the 1st of June. These leaves were used to protect the roses from winter kill. A compost prepared in this manner will contain billions and billions of black spot killing bacteria and is the second line of defense in the supression of black spot. The first line of defense was in the purchase of black spot resistant rose cultivars. Rose FloraTM also contains a newly added systemic bacteria that is effective in the pineapple industry against fungi that infiltrate the interior parts of that fruit. Whether this strain of systemic bacteria will be effective against downy mildew or black spot is unknown. What is known is that Rose FloraTMwill destroy the following fungi:
Aspergillus
Bipolairs sp.
Cephalosporium sp.
Chaetomium sp.
Colletotrichum magna
Fusarium oxysporum
Marssonina rosae
Phytophthora cinnamomi
Phytophtthora citricola
Phytophtthora citrophthora
Phytophtthora parasitica
Phyhtthora cactorum
Pythium aphanidermatum
Phythium ultimum
Rhizoctonia solani
Sclerotium folfsii
Verticillium albo-atrum
Verticillium dahliae
Verticillium sp.
Rose FloraTM will also destroy the pathogens E Coli and Salmonella4.
Rose FloraTM can be purchased only from:
603 N. Kimball
Excelsior Springs, Mo 64024
1-800-583-1939
Voice & Fax 1-816-630-3399
e-mail jngraff@better-flora.com
web http://www.better-flora.com
WILT-PRUFR is a natural pine oil emulsion that is not damaged by freezing, will not solidify in storage and is non-toxic to eyes and skin. It is a natural product derived from the resin of the pine tree which is called a polyterpene polymer or more specifically a beta-pinene polymer which is a film forming short chain polymer component. When this product is sprayed on plant surfaces, the water used to dilute it evaporates leaving a soft, flexible film which degrades one molecular layer at a time when exposed to air and light. The film immediately starts a polymerization into a longer chain, higher weight molecule. However, the entire thickness of the film does not polymerize at the same rate. Only the surface molecular layer is going through rapid polymerization. The molecular layer of the film that is attached and sticking to the leaf is staying a low weight, soft, sticky substance. The film slowly weathers away through this polymerization mode where the top layer fully polymerizes becoming a solid material. It powders away in microscopic flakes which are either washed or blown away, as the rest of the layers go through the same process until the entire film is weathered away. This normally takes about two months under hot, summer conditions and about four months under cold weather conditions. WILT-PRUFR will not interfer with plant growth or materially affect respiration, osmosis, or photosynthesis5.
WILT-PRUFR can also be purchased from Better Flora. See above address and telephone numbers.
Dormant Season
Dormant Season
Dormant Season
Dormant Season
Dormant Season
Dormant Season
Dormant Season
Dormant Season
Dormant Season
Dormant Season
Dormant Season
When you mix Rose FloraTM, as per directions (5 parts), with WILT-PRUFR concentrate (1 Part), according to directions you end up with a dormant coating on your bushes that will protect them from excessive moisture loss due to the anti-transpirant qualities of WILT-PRUFR and you will add the blackspot killing effects of Rose FloraTM. If, at this time, you add a broadcast treatment of Rose FloraTM applied to the rose bed soil you will help discourage black spot spores from over-wintering.
Growing Season
A topical treatment consisting of 10 parts reconstituted Rose FloraTM (according to directions) to 1 part of concentrated WILT-PRUFR liberally applied to all parts of the rose bush including the bottoms of all leaves should be used early in the season with the advent of maturing foliage and repeated every two months. You do not want to wait until you observe black spots on your foliage. The idea is prevention. The polymer coating makes it physically more difficult for the two cell black spot spore to penetrate the leaf surface and the Bacterium in Rose FloraTM is a further discouragement. The polymer coating also discourages sporulation of existing black spot leisions and therefore tends to hold down the spread of the fungus. A good spring time broadcast treatment of the entire rose bed and all its inhabitants (using only Rose FloraTM) prior to the appearance of any foliage is a good preventive measure and a weekly spraying of the lower foliage throughout the growing season with just Rose FloraTM, is recommended. Rose FloraTM is compatatible with all fungicides and insecticides.
It should be pointed out that there are many races (strains) of the black spot fungus. Often times you will hear an experienced rosarian allude to the fact that his current spray program is no longer effective against black spot. As fungicides are used in the rose garden there will develop resistant races through mutation or hybridization. Each time you introduce a newly acquired cultivar, it is possible, with it comes a race of black spot that is new to your garden. For this reason the author completely immerses each newly acquired cultivar in a solution of Rose FloraTM.
Powdery mildew is easily controlled with this program. Since this fungus occurs on the exterior surface of the leaf, a spraying consisting of 3% WILT-PRUFR and 97% Rose FloraTM (again, prepared as per directions) makes it impossible for powdery mildew to live and proliferate in this environment. This less concentrated mixture can be applied weekly or as needed without damage to your plant. Since powdery mildew likes new foliage, you might want to have a small sprayer handy, filled and ready to treat newly opening foliage.
To further complicate matters it should be pointed out that there exists two types of black spot resistance. One is phenotypic resistance in which case a variety might be highly resistant to black spot in one location but not so resistant in another. An example is the cultivar Livin Easy (AKA Fellowship) which is totally resistant in the authors garden in the Kansas City area but not as resistant in College Station, Texas. (It is still considrered highly resistant in Texas.) The other type of black spot resistance is genotypic resistance and is due to the presence of resistant genes and as such is not affected by climate, location or horticultural practices.6
The following list of highly black spot resistant roses has been compiled from research performed by Texas A&M, the author, the Minnesota Landscape Arboretum and anecdotal information from the suppliers listed at the end of these lists. Roses marked with an asterisk indicate very preliminary results or strongly anecdotal evidence that indicates a strong resistance to black spot. All of the roses listed with KC as a location were grown by the author and have undergone only one year of evaluation. This evidence should be taken lightly until stronger evidence can be accumulated through longer and more extensive trials. In the interim, it is hoped that this list will help steer potential newcomers to cultivars that can shrug off black spot and provide the beauty and charm that is expected from America's flower.
The column marked BS represents the Black Spot rating and Defol. stands for the defoliation rating found in Figure 1. The Loc. column is the location of the black spot evaluation. The Frag. column is an attempt to give a relative rating to fragrance and was conducted between the hours of 5:00 AM and 9:00AM during the first flush of blooms in the early summer and again during the cooler mornings of September. Obviously, fragrance is a subjective, fleeting, and sometimes highly variable characteristic of the rose and is given here only as an aid. The ARS Rating and color is taken from the 1997 ARS Handbook for Selecting Roses. The Hardy column indicates the zones where the variety is expected to perform well. The Availability column and the numbers indicate the source of the individual rose. These sources and their numbers are listed at the end of the lists.
Classifications of Roses
F = Floribunda
GR = Grandiflora
HMSK = Hybrid Musk
HP = Hybrid Perpetual
HRG = Hybrid Rugosa
HSPN = Hybrid Spinosissima
HT = Hybrid Tea
K = Kordesii (S)
LCL = Large-flowered Climber
MIN = Miniature
Pol = Polyantha
S = Shrub
SP = Species
Tea = Tea
Classification of Colors
AB = Apricot Blend
DR = Dark Red
DP = Deep Pink
DY = Deep Yellow
LP = Light Pink
LY = Light Yellow
MP = Medium Pink
MR = Medium Red
MY = Medium Yellow
OB = Orange Blend
OP = Orange Pink
OR = Orange Red
PB = Pink Blend
RB = Red Blend
W = White, near white & white blend
YB = Yellow Blend
Table 1
Cultivars with High Resistance to Black Spot
Cultivar Class BS Defol. Loc. Frag. ARS Rating & Hardy Availability
Color Zone
Alba Meidiland S 0.75 0.50 TX ---- 8.3 W 5 5
A. McKenzie S 0.00 0.00 TX 6.0 --- RB 3-4 5,6
Ambridge Rose S 0.00 0.00 KC 9.0 --- AB 5 4
Alec's Red * HT 0.00 0.00 CA 7.5 7.5 MR 5 5,6,7
Auguste Renoir* HT ----- ----- CA 7.0 --- MP 5 4
Belle Story S 0.00 0.00 KC 8.0 8.9 LP 5 4,5,9
Blanc Double
de Coubert S 0.00 0.00 KC 7.5 8.7 W 3-4 1,4,5,9
Cultivar Class BS Defol Loc Frag ARS Rating & Hardy Availability
Color Zone
Caramella* HT 0.00 0.00 CA --- --- AB 5 6,7
Carefree Beauty S 1.50 1.75 TX --- 8.5 MP 4 1
City of London* F ----- ----- CA 9.2 7.6 LP 5 5,6,9
Constance Spry S 0.00 0.00 KC 8.0 8.5 LP 4 4,5,9
Dortmund K 1.33 2.33 TX --- 9.4 MR 5 1,5,9
Frau Dagmar Harstrup HRG 0.00 0.00 KC 8.5 8.5 W 2-3 4,5,6
Frederic Mistral* HT 0.00 0.00 CA 7.0 --- LP 5 4,6
Gertrude Jekyll S 0.00 0.00 KC 9.0 --- MP 5 4,5,8,9
Gruss an Aachen F 0.00 0.00 KC 5.0 8.3 LP 5 1,2,5
Hansa HRG 0.00 0.00 KC 7.0 8.3 MR 3 1,5,6,8,9
Hawkeye Belle* S ----- ----- MN 8.5 7.6 W 4 2,6
Henry Hudson HRG 0.00 1.0 TX 8.0 9.1 W 2-3 4,5,6
Henry Nevard* HP 0.00 0.00 CA 8.0 6.2 DR 4 2,5
Jens Munk HRG 0.00 0.00 TX 5.0 9.2 MP 2-3 1,5,6
John Davis S 0.75 1.50 TX 5.0 8.5 MP 3 5,6
Lafter HT 0.75 0.50 TX --- --- YB 5 ---
Lilac Rose S 0.00 0.00 KC 9.5 --- PB 5 4,9
Livin Easy F 2.25 4.50 TX --- --- OB 5 1
Mabel Stearns S 0.00 0.00 KC 7.0 7.4 MP 4 4
Nearly Wild F 1.00 1.66 TX --- 7.4 MP 3-4 6,9
New Dawn LCL 0.00 0.00 KC 5.0 8.5 LP 4 1,2,5,6,9
Pearl Meidiland S 0.00 2.00 TX --- 8.7 LP 5 9
Polka* LCL 0.00 0.00 CA UNK --- OB 5 4,6
Prairie Harvest* S 0.00 0.00 MN 8.5 --- W 4 2,3
Prairie Sunrise* S ---- ---- MN 8.0 --- OB 4 3
Roselina HRG 0.00 0.00 KC 7.0 --- PB 4 6,8
Roseraie de-
l'Hay HRG 0.00 0.00 KC 9.0 9.0 DR 4 4,5,6,9
Roundelay* GR 0.00 0.00 CA --- 6.1 DR 5 5,7
Scarlet Meidiland S 0.5 1.50 TX --- 7.6 MR 5 4
Sharifa Asma S 0.00 1.00 KC 9.0 --- LP 5 4
Stanwell -
Perpetual* HSpn 0.00 0.00 CAN 8.5 8.5 W 3 5
The Fairy POL 0.00 0.00 TX --- 8.7 LP 4 2,8,9
The McCartney-
Rose* HT 0.00 0.00 CA 7.5 --- MP 5 7
The Pilgrim S 0.00 0.00 KC 5.0 --- MY 5 4,9
The Wife -
of Bath S 0.00 0.00 KC 5.0 7.5 PB 5 4
Wanderin' Wind* S ---- ---- MN 7.5 --- LP 4 3
Wenlock S 0.00 0.00 KC 7.0 7.2 MR 5 4,5,9
Willliam Baffin K 0.00 0.75 TX --- 8.9 DP 3 1,5,6,8
Wind Chimes HMSK 0.00 0.00 KC 5.0 8.0 MP 4 2
Winter Sunset* S ---- ---- MN UNK --- MY 4 3
Yankee Doddle HT 0.00 0.00 CA 6.0 5.4 YB 5 7
The following list of roses are cultivars with a moderate amount of resistance to black spot. Just remember that some of these roses will lose up to 62% of their leaves by mid summer without spraying.
Table 2
Cultivars With Moderate Resistance to Black Spot
Information Provided by Texas A&M University
Cultivar Class BS Rating Defoliation Rating
All That Jazz S 1.5 6.25
Montezuma GR 2.00 4.66
Safrano TEA 2.25 5.25
Perfect Moment HT 2.50 2.00
John Cabot S 2.50 2.75
Crimson Glory HT 2.50 3.00
York and Lancaster D 2.66 2.00
Simplicity F 2.75 2.25
Duet HT 2.75 3.25
Tiffany HT 2.75 4.00
Electron HT 3.00 2.75
Century Two HT 3.00 3.25
Pink Meidiland S 3.25 2.00
Sweet Inspiration F 3.25 3.00
Gold Medal GR 3.25 4.00
Mr. Lincoln HT 3.25 4.25
Tournament of Roses GR 3.25 5.25
Shining Hour GR 3.50 2.50
Oklahoma HT 3.50 3.75
Madame Hardy D 3.50 4.25
Gartendirektor Otto Linne S 3.50 5.25
Iceberg F 3.75 3.00
Rio Samba HT 3.75 5.50
Touch of Class HT 4.00 5.33
Heirloom HT 4.00 6.00
Morden Blush S 4.25 1.75
Shreveport GR 4.25 2.75
Sun Goddess HT 4.25 5.00
Playgirl F 4.50 3.25
Carrousel GR 4.50 3.75
Angel Face F 4.50 4.75
Table 3
Cultivars With Low Resistance to Black Spot
Information Provided by Texas A&M University
Cultivar Class BS Rating Defoliation Rating
Old Blush Ch 1.50 7.25
Sheer Elegance HT 1.50 8.75
America's Choice HT 1.66 8.66
Sexy Rexy F 2.00 8.75
Tropicana HT 2.00 9.00
Ingrid Bergman HT 2.50 6.50
Golden Showers LCL 2.75 6.00
Garden Party HT 3.25 6.25
John F. Kennedy HT 3.25 6.50
New Day HT 3.33 7.33
Olympiad HT 3.66 6.00
Playboy HT 4.25 5.75
Honor HT 4.50 7.50
Carefree Wonder S 5.00 3.50
Picasso F 5.00 6.00
Persian Yellow SP 5.33 7.66
Peace HT 5.46 5.04
Salsa HT 5.50 8.75
Pleasure F 6.00 7.00
Intrigue F 6.00 8.00
Amber Queen F 6.50 8.25
Pinstripe MIN 6.50 8.50
Sunbright HT 7.25 8.75
Table 4
Black Spot Susceptible Cultivars
Information Provided by Texas A&M University
Cultivar Class BS Rating Defoliation Rating
Impatient F 4.00 8.25
Bonica '82 S 4.25 8.25
Queen Elizabeth GR 5.33 8.33
Ole' GR 5.33 9.00
Purple Tiger F 8.50 9.00
Sunflare F 9.00 9.00
Conclusion
Please note that in Table 4 the rose, Queen Elizabeth will become almost totally defoliated without a good spray program. Unfortunately this is probably the most recommended rose for a beginner to try, with the best chance for failure. Perhaps the second most recommended rose is Tropicana and from Table 3 you can imagine the newcomer's disappointment when all the foliage falls off and he is left to stare at a bunch of leafless, scraggly canes, headed in an every-which-way direction. Would it not be better to recommend roses that will not defoliate? Remember the old adage:
First grow great foliage then good blossoms will follow!
Climbers
1. New Dawn, LP, Very hardy, consistent extremely resistant to diseases & unbeatable, 12 - 15 ft.
2. William Baffin, MR, Very hardy, beautiful, floriferous & resplendent. 9 - 12 ft.
3. Dortmund, MR, a kordesii which means hardy and disease resistant. 10 - 15 ft
4. Polka, OB, Hardy to zone 5, tough and disease free, so says the supplier. 10 - 12 ft.
Note: Sometimes climbers have a way about them that leaves them rather barren at the base of the plant. A good way to fill in this barren area is with a low growing hybrid rugosa rose such as Frau Dagmar Harstrup or Henry Hudson. These rugosas provides beautiful foliage, great blossoms and tremendous fragrance. Just remember that they will not tolerate chemical sprays but Rose FloraTM and WILT-PRUFR work well if needed for other nearby varieties. Both of these spray ingredients are well tolerated by the rugosas.
Hybrid Teas
1. Frederic Mistral, LP, Perfect HT form, potent fragrance, "especially resistant to black spot".
2. Auguste Renoir, MP, OGR form, 5 inch blooms very full & double, fragrance will fill a room.
3. Mabel Stearns, MP although classed as a shrub, fits here. Good cut, long stem HT blooms, very hardy.
4. Yankee Doodle, YB, an AARS winner from 1976 described in the book, Roses of America, Henry Holt & Company, New York as follows:
"Enormous, urn-shaped buds open to large, fragrant, cupped flowers, yellow-orange with apricot-pink centers. Over 70 petals. Vigorous, tall-growing rose. Tough,exceedingly disease-resistant foliage. Blooms constantly all season. A good rose for a beginner."
Floribundas
1. Livin Easy, OB, great bright color, constantly in bloom, no fragrance.
2. Gruss an Aachen, LP, a good old-timer with no black spots.
3. Nearly Wild, MP, wild with wild , specie-type flowers all season.
4. City of London, LP, ravishing fragrance, "Blossoms on a bush that is ironclad against disease".
Hybrid Rugosas
This group of roses are unlike typical modern roses. The foliage is worth the investment, perhaps the most beautiful of all foliage. The fragrance is usually very strong with many blooms and good repeat. A privacy hedge with some of the taller cultivars can be exceptional. Don't expect long stem HT type blooms. They come in clusters with some opening each day and some falling by the wayside. They are very hardy, disease resistant, and they will not tolerate chemical sprays.
1. Roseraie de l'Hay, DR, Great for a privacy fence, great fragrance, bloom & color. 6 - 8 ft.
2. Frau Dagmar Harstrup, MP, Low growing, 2 -3 ft., great fragrance, hardy & disease free.
3. Blanc Double de Coubert, W, Very white, very fragrant and very disease free, 4 - 5 ft.
Small Shrubs
1. The Fairy, LP, A reliable old-timer that blooms and blooms in clusters of small blooms. 2 - 3 ft.
2. Alba Meidiland, W, Very double, profuse clusters. 3 ft.
3. Carefree Beauty, LP, A beautiful double, abundant blooms. 3 ft.
Tall Shrubs
1. Prairie Harvest, LY, HT blooms,very fragrant & hardy. 5 ft.
2. Hawkeye Belle, W, Grandiflora type blooms, intensely fragrant & hardy. 4 ft.
3. Wanderin' Wind, LP, HT type blooms, double, high center & fragrant. 6 ft.
English Roses
1. Ambridge Rose, AB, Unforgetable fragrance. 3 ft.
2. Lilac Rose, PB, Intense, delicious, unusual fragrance. 3 ft.
3. Sharifa Asma, LP, Tough foliage, one of the best, highly fragrant. 3 ft.
4. The Pilgrim, MY, Beautiful, reliable, & lightly fragrant.
5. Wenlock, MR, Old rose fragrance, good repeat and no BS the 1st year. 4 ft.
Special Recommendations
1. Stanwell Perpetual, W, a very fragrant favorite for 159 years. Worthy of any garden.
Was the favorite of Gertrude Jekyll and is sure to be a favorite of yours. 5 ft.
2. Prairie Harvest, LY, mentioned earlier as a tall shrub but worthy of special note.
3. Wanderin' Wind, LP, mentioned as a preferred tall shrub but worth repeating. 6ft.
4. Hawkeye Belle, W, this rose along with the two previous roses are some of Dr.
Griffith Buck's best and most disease resistant cultivars. They should not be lost
and forgotten, as they are winners in every sense of the word.
Best Yellows
1. Prairie Harvest, HT type Shrub
2. Winter Sunset, Bright medium yellow, double, blooms in clusters, prolific.
3. Yankee Doodle, HT
Best Reds
1. Alec's Red, HT
2. Wenlock, English Shrub
3. Dortmund, Kordesii, tall shrub or climber.
Best Whites
1. Stanwell Perpetual, Hspn
2. Hawkeye Belle, Grandiflora type shrub.
Best Oranges
1. Livin Easy, F
2. Prairie Sunrise, S, Orange-apricot, very double, quartered, heady clove fragrance, very long lasting.
"In quest for a century rose, this one is a runner-up"....Sam Kedem.
1. Butner's Old Mill Nursery
806 South Belt Hwy.
St. Joseph, MO 64507
1-800-344-8107
2. Roses of Yesterday and Today, Inc.
803 Browns Valley Road
Watsonville, CA 95076
1-404-724-3537
3. Sam Kedem Greenhouse and Nursery
7874 165th Street E.
Hastings MN 55033
1-612-437-7516
4. Wayside Gardens
1 Garden Lane
Hodges, SC 29695-0001
1-800-845-1124
5. Pickering Nurseries, Inc.
670 Kingston Rd.
Pickering, ONT LIV 1A6
1-905-839-2111
6. Hortico Inc.
723 Robson Rd.
Waterdown, ON LOR 2H1
1-905-689-6984
7. The Rose Ranch
P.O. Box 10087
Salinas, CA 93912
1-408-758-6965
8. Jackson & Perkins
1 Rose Lane
Medford, Oregon 97501-0702
1-800-292-4769
9. Garden Valley Ranch Nursery
498 Pepper Road
Petaluma, CA 94952
1-707-795-0919
Endowed Chair
in
Rose Genetics
"We now need to unlock the treasures of the entire rose genus.
One man and one lifetime are not enough. The logical answer
is a university, where the torch can be passed."
Robert E. Basye
Endowment to Establish a Chair in Rose Breeding and Genetics
For the last 200 years rose breeders have made tremendous advances in the development of better rose flower types and plant growth types. A rainbow of colors and a wide spectrum of flower and plant forms are available. We owe much to those who created this cornucopia of beauty. However, extensive research remains to be done. Little sustained effort has been devoted to developing plants which are resistant to diseases and pests. Resistant plants would not require constant sprays to maintain their beauty. This is the type of plant the rose bloom deserves!
Black spot is the most devastating and wide spread of the rose diseases. This fungus attacks practically all of our modern rose cultivar, but there are numerous wild roses which are left untouched! The challenge is to transfer the resistance from wild rose species to modern rose types. Little work has been done with the wild species because they only have half the number of chromosomes as do the cultivated roses. Hybrids between most wild types and cultivated roses are triploids which are sterile and dead ends for breeding. New approaches which can incorporate the traits of the diploids into the commercial tetraploid rose cultivar group are needed.
The Rose Breeding and Genetics Program will use a multidisciplinary team to combine the traditional sciences of breeding, genetics, plant pathology, entomology and plant physiology with the newly developing tools of biotechnology. The major objective is to develop unique sources of disease resistant germplasm that other breeders and hybridizers can use in developing disease and pest resistant rose cultivars.
Goals of the Robert E. Basye Chair in Rose Genetics
Establishment of a rose germplasm collection. The strength of any breeding program is the genetic diversity in its gernplasm collection. A wide range of variability is available in the genus Rosa. Unfortunately, just a small proportion of this variability has been used in breeding up to the present time. This diversity needs to be collected and evaluated for a series of traits. Initial efforts will be focussed on the collection of diploid rose species, their hybrids, and other rose germplasm that may be resistant to pests or diseases.
Incorporation of traits from the diploid species into the tetraploid germplasm. Direct crosses between diploids and tetraploids usually result in sterile triploids. A unique approach to circumvent this sterility block is to produce amphidiploids from the diploids. Two distantly related diploids are crossed which results in a sterile diploid. This sterile diploid subsequently is treated to double its chromosome number which results in a fertile tetraploid which has two sets of chomosomes, one from each of the original diploid species and a commercial-type tetraploid indicates that the resistance is inherited.
Search for sources of high resistance or immunity to black spot. Dr. Basye has observed that high levels of black spot resistance exist in diploid rose species from seven sections of the genus Rosa. Field trials are being conducted to verify these preliminary observations and to evaluate a range of other roses, both diploid and tetraploid, for their resistance to black spot and other diseases.
Marker-assisted selection for black spot resistance. Resistance to black spot is difficult to measure due to complex interactions among the environmental conditions, the pathogen and the rose plant. There is a need to find an easily identified marker gene closely linked to black spot resistance. This would enable the elimination of the majority of susceptible seedlings from the breeding population at an early stage. One way to do this is to make a genetic linkage map of the rose using easily selected markers (morphological traits, isozymes, RAPD markers, RFLPs) and identifying the ones that segregate with black spot resistance. This work could trace the inheritance of a multitude of important traits in the rose. This research would lead to better ways to finger print cultivars and set the stage for the development of other marker assisted screening protocols.
Regeneration and transformation protocols. Genetic engineering, the insertion of genes from one plant into another, is beginning to impact the development of agriculturally important plant species. Some whole plants have been produced from single cells and callus, and in one case, genetically transformed rose plants have been produced. More work needs to be done to develop procedures to efficiently regenerate and transform a wide range of rose cultivars not just a few specific types. When this is accomplished, biotechnology will begin to make an important contribution in the field of rose improvement.
For further information about how you can support the
Robert E. Basye Chair in Rose Genetics,
contact R. Daniel Lineberger or David H. Byrne,
Department of Horticultural Sciences,
Texas A&M University,
College Station, Texas 77843-2133
Phone 409-845-5278
FAX 409-845-0627
References & Acknowledgements
1. Black Spot Revisited by George "Dick" Barse, 1995 American Rose Annual, page 74
2. Field Study of Black Spot Resistance in the Rose by William A. Black, David H. Byrne
and H. Brent Pemberton, Dept. of Hort. Sciences, Texas A&M University.
3. The Use of Amphidiploidy in the Development of Black Spot Resistant Rose Germplasm, by
D. H. Byrne, W. Black, Y. Ma, and H.B. Pemberton, Texas A&M University
4. Information provided by:
Better Flora
603 N. Kimball
Excelsior Springs, MO 64024
1-800-583-1939
1-816-630-3399 Voice & Fax
5. Information provided by:
WILT-PRUF Products, Inc
P.O. Box 469
Essex, CT 06426-0469
6. Microorganisms, Roses and Rosarians by Dr. Lakshmi M. Sridharan, 1995 American Rose Annual
page 68
7. Compendium of Rose Diseases, APS Press
8. Hardy Roses by Robert Osborne, A Garden Way Publishing Book, Storey Communications, Inc.
Pownal, VT 05261
9. Kathy Zuzek, Minnesota Landscape Arboretum
10. Griffith Buck, His Thoughts...His Roses, by Morris Anderson, 1996 American Rose Annual
Page 22
11. William J. Radler,
10020 W. Meadow Drive
Greenfield, Wisconsin 53228
12. Roses Of America, The Brooklyn Botanic Gardens, by Stephen Scanniello & Tania Bayard
A Donald Hutter Book, Henry Holt & Company, New York.