"biocontrol" is one method that one can try for blackspot. The following may be useful in putting the concept of biocontrol into layman terms: "Disease-suppressive soil microorganisms have been found in many places. In monoculture wheat the severity of "take all" disease often decreases within three to five years. This phenomenon is known as "take all decline," and is considered an effective natural control. Although the mechanisms are not completely understood, the decline is associated with changes in soil microorganisms that compete with and prey on the fungus. Melon plants grown in the Chateaurenard region of France do not show Fusarium wilt symptoms even though the fungus is present in the soil. Soils with suppressive characteristics tend to develop slowly and are usually found in fields where perennial crops or monocultures have been grown for many years. Suppressiveness may be lost if the monoculture is interrupted even for one year, or if pesticides are applied. For example, researchers first recognized soils suppressive to cereal-cyst nematode when nematode numbers increased after application of a broad-spectrum biocide. Many species of fungi and bacteria in the genera Trichoderma, Streptomyces, Bacillus and Pseudomonas suppress diseases, but at this time only a few strains are commercially available. Additional commercial products may be available soon, however, as this is currently an active research area." The quote was taken from: Http://www.cals.ncsu.edu/sustainable/peet/IPM/diseases/org_cert.html ---------------------------------------------- The following article from the Maine Rose Society web page ( http://www.mainerosesociety.com/articles/control.html ) was written by by DR. LAKSHMI SRIDHARAN, who should be familar with those of you that are members of the American Rose Society. ----------------------------------- Examples that friendly fungi do exist: Http://taylorandfrancis.metapress.com/app/home/contribution.asp?wasp=59ghxnlylp03feg2dr2p&referrer=parent&backto=issue,1,10;journal,2,54;linkingpublicationresults,1:100635,1 Http://taylorandfrancis.metapress.com/app/home/contribution.asp?wasp=4g1ltlxhtr3ya223recn&referrer=parent&backto=issue,8,10;journal,4,54;linkingpublicationresults,1:100635,1; Http://taylorandfrancis.metapress.com/app/home/contribution.asp?wasp=8000375kwm5qnk5e7y47&referrer=parent&backto=issue,1,10;journal,6,54;linkingpublicationresults,1:100635,1; Http://taylorandfrancis.metapress.com/app/home/contribution.asp?wasp=07wckmqrxr3jqg6kducy&referrer=parent&backto=issue,9,10;journal,7,54;linkingpublicationresults,1:100635,1; ------------------------------------------------ Blackspot on roses is scientifically called "diplocarpon rosae". The link below reports that trichoderma harzianum is a promising control - see their exact wording (the document is a PDF document. The applicable section is easily found by typing diplocarpon into the PDF find command - the binoculars). Http://www.gtz.de/ecosan/download/Bangalore03-Ramanujam.PDF ------------------------------------------------------ Title: The Abundance and Structure of the Root-Associated Microbial Complexes of Two Greenhouse Rose Cultivars. Authors: Polyanskaya, L. M.; Ozerskaya, S. M.; Kochkina, G. A.; Ivanushkina, N. E.; Golovchenko, A. V.; Zvyagintsev, D. G. Authors affiliation: Faculty of Soil Science, Moscow State University, Vorob'evy gory, Moscow, Russia. Published in: Microbiology (Moscow, Russian Federation)(Translation of Mikrobiologiya), volumn 72, pages 496-502, (2003). Abstract: "The study of the root-assocd. microbial complexes of affected and healthy rose plants of two cultivars (Grand gala and Royal velvet) grown in a greenhouse showed that the biomass of eukaryotic microorganisms in the rhizoplane and rhizosphere of healthy rose plants and in the surrounding soil was considerably lower than in the same loci of affected plants. In contrast, the biomass of root-assocd. prokaryotic microorganisms was higher in the case of healthy than in the case of affected rose plants. The root-assocd. bacterial complexes of both affected and healthy rose plants were dominated by the genera Arthrobacter, Rhodococcus, and Myxobacterium and did not contain phytopathogenic bacteria. The root-assocd. fungal complex of healthy roses was dominated by fungi of the genus Trichoderma, whereas that of the affected rose plants was dominated by the species Aureobasidium microstictum. The affected cane cuttings and cankers occurring on affected canes were found to contain Coniothyrium fu-ckelii (the causal fungus of rose stem canker) and sclerotia of Botrytis cinerea (the causal fungus of gray rot). The micromycete complex of healthy rose plants was not so diverse as was the micromycete complex of affected rose plants." ---------------------------------------------- Title: Biological control of black spot of rose caused by Dipocarpon rosae . Authors: Prasad, R. D.; Rangeshwaran, R.; Sunanda, C. R.; Vinita, J. Authors affiliation: Project Directorate of Biological Control, Post Bag No. 2491, H.A. Farm Post, Bellary Road, Hebbal, Bangalore 560 024, India. Published in: Annals of Plant Protection Sciences,volumn 10, pages 256-259, (2002). Abstract: "Fungal biological control agents (Trichoderma harzianum , T. viride and Chaetomium globosum ) were used either alone or in combination with fungicides (chlorothalonil and mancozeb) to manage black spot of rose caused by D. rosae under greenhouse conditions. Black spot incidence in biological control agent and/or fungicide treatments was significantly low (disease ratings from 0.33 to 3.33) compared to the control at all observation dates. After 100 days of spraying, defoliation was lowest with chiorothalonil, Trichoderma harzianum +chlorothalonil, C. globosum +chlorothalonil and T. harzianum +mancozeb treatments. The highest mean vigour index was recorded in T. harzianum treatment. The highest flower production was recorded in C. globosum +chlorothalonil treatment (4.33) followed by T. harzianum alone and T. harzianum +chlorothalonil treatment (4.00)." -------------------------------------------------- Cornmeal is considered to be a good food for the friendly fungus "trichoderma harzianum". The fungus is available commercially, see: http://www.ipmofalaska.com/files/trichoderma.html There may be another benefit to this fungus as there is a report that it helps root growth: Title: Effect of Trichoderma Colonization on Auxin-Mediated Regulation of Root Elongation. Author: Bjoerkman, Thomas. Department of Horticultural Sciences, Cornell University, Geneva, NY, USA. Published in: Plant Growth Regulation, volumn 43, pages 89-92, (2004). Abstract: "The biocontrol fungus Trichoderma harzianum 1295-22 increases root growth in addn. to roles in suppressing disease. Its agricultural use could be expanded if the mechanism of growth enhancement were known. Among the proposed mechanisms of growth enhancement is that the fungus counteracts auxin inhibition of root-cell elongation. We tested whether there was evidence for a secreted auxin inhibitor, for enhanced auxin degrdn., or for altered auxin sensitivity. Our results provide no support for any of these mechanisms. Trichoderma secretions inhibited growth, whereas an auxin inhibitor would increase growth. Auxin inhibited growth to the same extent in colonized and uncolonized roots, indicating no change in auxin sensitivity. Endogenous auxin levels maintained growth closer to the max. in uncolonized roots, indicating stronger auxin limitation of growth in colonized roots. These tests indicated that Trichoderma-colonized roots had a faster max. growth rate, but an unchanged response to auxin." -------------------------------------------- Even if naturally occurring trichoderma harzianum only reduces the amount of blackspot fungus by 10 to 20 % (the numbers are just a guess), there are probably going to be a number of different "friendly" fungi in an organic garden. For example, the following paper reports that 2 fungi that are now recognized as biocontrol potential have increased levels on blackspot infected leaves: ------------------------------------ Title: PHYLLOPLANE MICROORGANISMS OF ROSA CULTIVAR PICADILLY FOLLOWING INFECTION BY DIPLOCARPON-ROSAE Author: HAYES A J Author Affiliation: DEP OF FORESTRY AND NATURAL RESOURCES, UNIV OF EDINBURGH, UK. Published in: Transactions of the British Mycological Society, volumn 79, pages 311-320, (1982). Abstract: "The phylloplane microflora of the hybrid tea rose cultivar Picadilly was studied for 2 growing seasons on healthy leaves and on leaves infected by D. rosae. Large increases in numbers of yeasts and bacteria on healthy leaves were noted from the end of July until the beginning of Oct. Late in the growing season numbers of all types of microbes increased dramatically. Following infection by D. rosae numbers of microbes generally showed a marked increase, but this was not always sustained. Cryptococcus laurentii and Micrococcus sp. populations on infected leaves were 3-4 times those on correspondingly healthy leaves. The species composition and changes in numbers of phylloplane microbes are compared with descriptions of microflora isolated from leaves of other plants and possible reasons for the observed differences are discussed." -------------------------------------- The following two links are Google searches for the two fungi listed and the word biocontrol. --------------------------------------- Http://www.google.com/search?hl=en&lr=&q=%22cryptococcus+laurentii%22+biocontrol&btnG=Search ----------------------------------------------- Http://www.google.com/search?hl=en&lr=&q=micrococcus+biocontrol&btnG=Search ------------------------------------------- The science of biocontrol is still in its infancy. The use of Chitosan is one of the early results of this area of research. The following is the EPA summary: ( Http://www.epa.gov/pesticides/biopesticides/ingredients/factsheets/factsheet_128930.htm ) "SUMMARY Chitosan is used primarily as a plant growth enhancer, and as a substance that boosts the ability of plants to defend against fungal infections. It is approved for use outdoors and indoors on many plants grown commercially and by consumers. The active ingredient is found in the shells of crustaceans, such as lobsters, crabs, and shrimp, and in certain other organisms. Given its low potential for toxicity and its abundance in the natural environment, chitosan is not expected to harm people, pets, wildlife, or the environment when used according to label directions." -------------------------------------------- There is a scientific literature report of 10 - 20 % effectiveness against blackspot. Title: Chitosan as the biocontrol agent of fungal pathogens; activity and mode of action. Authors: Wojdyla, Adam T. Authors affiliation: Research Institute of Pomology and Floriculture, Skierniewice, Pol. Published in: Bulletin of the Polish Academy of Sciences: Biological Sciences, volumn 51, pages 159-165, (2003). Abstract: "In in vivo expts. showed that chitosan added to potato dextrose agar at 3 mg/cm3 in 50% suppressed radial growth of Colletotrichum gloeosporioides and Phytophthora cryptogea. Another tested fungi were less sensitive to chitosan. ED50 for Cylindrocladium scoparium and Myrothecium roridum was more than 5 mg/cm3. In vivo expts. showed that only 10-20% effectiveness of the compds. against Diplocarpon rosae was found, when chitosan at 0.2-0.4 mg/cm3 was used for rose spraying. Also spraying of willow 2 times at weekly intervals against Melampsora epitea decreased the mean no. of rust pustules per leaf. Spraying of dieffenbachia 24 h before inoculation with M. roridum resulted in significant decrease of necrosis spread on leaves. Five days after inoculation the compds. inhibited the development of leaf spot about 94%. Chitosan applied preventively before inoculation of leaves gave significantly better results in the control of M. roridum than used 24 h after inoculation. Spraying of chrysanthemum, naturally infected with Puccinia horiana decreased the mean no. of pustules per leaf about 95%."

Hi Mike: Glad to hear from you, I'm too lazy to spray. Fifteen years ago, a neighbor saw me spraying roses with chemicals and told me, "why do you even bother growing roses with all these spraying?" Roses become unpopular when people associate roses with spraying. It's already a nuisance to spray my moldy shower stall with bleach/water solution. The pics I posted are FRESHLY dusted roses BEFORE another 20+ hours of rain. Today the rain washed most of the corn meal away, and the leaves are 100% green and healthy. My 10 Austins keep ALL their leaves green. I went and check the neighbors' disease-resitant roses, like Living Easy, and some single-petal species. They look horrible with yellow leaves after 5 days of constant rain, and no sun. It looks better dusting roses with corn meal using a flour sifter, and much faster than messy spray. My pics look bad because I threw corn meal by hand. The best thing about dusting with corn meal is the prevention of pathogenic fungi from germinating through the winter and inflicting more damage in the spring. It takes 10 days for the beneficial Trichoderma fungi to germinate from corn meal, and to suppress pathogenic fungi. I dusted August 1, September 1, September 17 (after 25+ hours of rain), and when I took the above posted pictures (Wed, Sept.28), after 3 days of rain. I finally see the sun this morning, Friday, Sept.30, after 5 days of constant rain.

Hi Kim, I just thought you might like to know that, quite against the odds, one of my friend's cuttings that had been wrapped for far too long in the newspaper did succeed after being planted up in a pot. All the others died, which was to be expected, given the circumstances. They were all the same rose, a Kordes Hybrid Tea called 'Perfect Moment'. I'm attaching a shot of it taken this morning. We've both taken a trip to our local old cemetery last week and taken cuttings, wrapped them in damp newspaper and sealed them in ziplock bags. I've put mine in our plant room (which is unheated - the temperature range here now is 7 - 15 degrees (Celsius) so I would estimate the plant room is about 13 or 14 without very much variation at all. There are no windows in it so it's dark. I will check the cuttings in a couple of weeks and hope to find calluses. If I'm lucky and there are calluses I'm thinking I should pot up into 2.5 litre pots with my usual one-third potting mix and two-thirds sand and leave the cuttings to overwinter outside in a protected spot. I leave here at the beginning of December and don't return until the beginning of March so the cuttings will have to fend for themselves. Two years ago I took cuttings using the 'conventional' method at this time of year and left the outside. I didn't have a very high success rate (four cuttings survived out of perhaps fifteen or sixteen). However, I do now have four lovely roses that I wouldn't otherwise have. Cheers Tricia

A good healthy soil growing strong and healthy plants can help minimize the occurrence of Black Spot, not eliminate it altogether but minimize it. A good healthy soil starts with the proper soil pH and balanced nutrients and that begins with a good reliable soil test. In addition roses grow quite well in soils that are well endowed with organic matter that are evenly moist but well drained. Along with the good reliable soil test perhaps these simple soil tests might be of some help. 1) Soil test for organic material. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top. 2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains’ too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up. 3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart. 4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell, to a point. Too much organic matter can be bad as well. 5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy. kimmq is kimmsr