Sure, I'll comment. It's a bunch of baloney. A myth that got started somewhere and keeps popping up from time to time. Here's the last thread that discussed this rumor, which, of course, references the one before that, which references the one before that in a never ending stream.

Gee I wonder how these things get started. Hehe.

Here is a link that might be useful: Milk for Mildew thread

Somebody tried it in our area, too, and found it didn't do anything but create even more white spots on your rose leaves, lol.

Drink the milk or putting it on your roses may give youir sour roses. If you must spray anything to prevent mildew, I found the oil in fish emulsion works as a barrier to the mildew spores and the fish emulsion is better for the roses.

As the link given by kstrong indicates, it is not a myth and there is solid scientific research on the subject.

Here is a link that might be useful: Google Scholar search

More research

Here is a link that might be useful: milk myth?

Sorry Henry -- it is a myth -- none of that "solid scientific research" says a darn thing about controlling existing powdery mildew on ROSES. Moreover, I've tried it, and it does not work. Don't waste your milk.

It seems as though it works for some and not for others, but there is no harm in trying. There are no permanent negative effects, so why not?

Over the past thirty years I think I have seen more hair-brained cures for common rose diseases and problems then I would care to mention here. Unfortunately, many people believe if they read the prescription in the New York Times or any other well-known publication, it must be true. Well, neither one of the methods mentioned here, the milk and water, or the baking soda mixture are worth the trouble. Anyone is welcome to try them as they wish, but they don't and won't work.

The following was stated: "Sorry Henry -- it is a myth -- none of that "solid scientific research" says a darn thing about controlling existing powdery mildew on ROSES."

H. Kuska reply. I am confused. The early link in this thread given in a response by kstrong contains a specific scientific study on roses which I posted in that thread.

If one would like to see more detail of a scientific study, there is considerable detail in the following patent application. The following is the results of Trial 8 (AMF is the shorthand used for "anhydrous milk fat" ).

"FIG. 15 shows that "Soy" and "AMF" were the best treatments providing significantly better PM disease control than "Supershield" fungicide, which in turn had significantly reduced disease relative to the "Water" and "Unsprayed" treatments."

Trail 8 is described:

"Trial 8

Materials and Methods

[0317]Mature rose plants of the PM-susceptible cultivar `Sahara` were pruned to a height of approximately 40 cm and potted into 20 cm diam. plastic pots with Dalton's potting mix. Plants were maintained in a controlled environment (CE) room set at a constant temperature of 20 C. and a 16 h photoperiod. Pots were hand-watered with tap water every two to three days. The plants were left for three weeks to establish, form new leaf growth, and infect naturally with PM before commencement of the trial. Roses buds and flowers were removed throughout the course of the trial.

[0318]There were five treatment applications at weekly intervals. All treatments were applied using hand-held mister bottles to the adaxial and abaxial leaf surfaces until runoff to ensure full coverage. There were six replicates (pots) per treatment. The pots were randomised within blocks on a single bench within the CE room, with one replicate plant from each treatment in each block.

[0319]Disease assessments were carried out immediately prior to each spray application and one week after the last spray. Assessments of PM were based on the disease rating scale in Table 1, except that assessments were not carried out on individual leaves as in Trials 1-3 and 7, because roses have relatively rapid growth and turnover of leaves. Rather, the disease rating was given as an overall average for the mature portion of the plant, excluding all the fresh unexpanded juvenile leaves. Data from the final assessment were analysed as a randomised block design (RBD), by analysis of variance (ANOVA), with means separation by Fisher's Least Significant Difference (LSD) (P----------------------------------------------------

Rose powerdy mildew is "sphaerotheca pannosa". There are 9 different strains with different virulences that have been identified in the literature ( http://www.apsnet.org/publications/phytopathology/backissues/Documents/1984Articles/Phyto74n01_100.pdf ).

The same fungus attacks plants similar to roses such as apples. (http://www.gardenguides.com/101425-controlling-powdery-mildew-organically-apple-tree.html )

Fine Henry, believe whatever you want to believe. I try to give only sound advice, and milk for mildew is not. Let us know when you have tried it and seen it work.

Since this seems to be a much debated subject and confusing.
Why not just try it and see for yourself bebba1 if it works or not in your area?
Many products/remedies are debated to whether they work or not.
Give it a try and please let us know the results.

A friend of mine swears by using Greencure mixed with alittle fish oil for powdery mildew.
Or just try the fish oil as stated by Karl above in his post.
We do not seem to get Powdery Mildew here on our roses, so, i've never needed to test these products/ remedies.
Good Luck!

kstrong, I am not questioning your personal results.

As indicated there are more than one strain and virulence. Also, I do not know your cultural practices. Some rose growers force their roses for show purposes by using large amounts of fertilizer, and/or hard pruning, some use harsh chemical sprays that weaken the plants by killing the "good soil cofactors" that help the plant stay strong and healthy. There are published scientific articles that the water used can affect the sucess of mildew spraying, that the temperature when spraying has an effect, that technique has an effect, and even how long the leaf stays wet has a measurable effect. Some people would be happy with something like a, say, 70% control while others ( particulary showers) feel something is a failure if it does not provide 100% control.
i.e. like just other aspects of rose culture, not everything that works for one individual will work for another with different variables, and/or expectations.

The point is that milk is an accepted form of mildew control based on scientific studies. If an individual does not have success, the question is why. What defeated the known antifungal properties of the milk?

The best source I have is Linda Chalker-Scott, a Washington horticultural educator who reviews the literature on milk in her book "The Informed Gardener Blooms Again." She concludes that there's no evidence for its use.

Henry, I question your analysis here. I both looked through your "Google Scholar" search and did a few of my own and did not come up with one single instance of a scientific study that said milk deters powdery mildew on garden roses. I saw zucchini and pumpkins, and I saw downy mildew in there, and I think I saw one study that said something very limited about milk fat combined with soybean oil emulsion (whatever that is) -- but if there is one such study out there that answers the original poster's question, please reference it.
Finally as a lawyer who does some patent work, I am very much aware that anyone can write anything they want in a patent application -- with or without basis.

So where is this study that says milk deters powdery mildew in garden roses at some specified application rate along the lines of the OP's question, (i.e. approx 7 parts water to 1 part milk with nothing else added to it)? If there is such a study, could you link to the study (and not a Google Scholar search or a 100 page compendium of mostly unrelated abstracts)?

Thanks

kstrong, as I said before it was in the thread that you linked to.

"Title: "Powdery mildew control on apple and rose using milk fat and soybean oil emulsions"
Authors: A. AH CHEE (1), K. V. Wurms (1)
(1) HortResearch

Published In: Phytopathology 96:S4
http://apsjournals.apsnet.org/doi/pdf/10.1094/PHYTO.2006.96.6.S1

Abstract: "Powdery mildew (PM) is a serious fungal disease in a wide range of horticultural crops that can adversely affect yield quantity and quality. This paper describes the potential of milk fat and soybean oil emulsions to control apple PM (Podosphaera leucotricha) on the cultivar Royal gala and rose PM (Sphaerotheca pannosa var. rosae) on the cultivar Sahara. Potted plants were kept under controlled environment conditions and subjected to weekly sprays of the two emulsions along with fungicide, unsprayed and water control treatments. In apple seedlings, the milk fat and soybean oil emulsions significantly reduced PM after 7 to 8 weeks, to an average infection of Please notice that this was published in June 2006. Professorroush5B, apparently the Linda Chalker-Scott paper on this subject also appeared in June 2006.

Exactly. If you notice -- what was linked in your post there was just 134 pages of abstracts about a whole bunch of different topics, mostly not related to mildew, roses, or anything else pertinent to this discussion. The ONLY thing in the whole 134 pages was the one paragraph that you copied above, which says nothing that answers the original poster's question. And again, who the heck knows what a mixture of "milk fat and soybean oil emulsion" actually is, or how it relates to the original poster's question.

I think my point is made and we should stop this nonsense.

kstrong, where does the abstract say that they mixed the milk fat and soybean oil?. If you have any doubt look at what they state for the apple 'There were no significant differences in PM control between the milk fat emulsion and fungicide treatments, but the soybean oil emulsion produced disease control equal to or exceeding that of the fungicide (Kumulus® DF, BASF, Germany).' The rose results were stated very briefly, but they use the plural 'emulsions' and the word 'average'. Why did the authors not write out the results separately for the rose results? Of course I cannot say for sure, but I 'think', since the results averaged less than 2% infection that the 2 oils gave results within experimental error of each other so it was not necessary. (Abstracts are expected to be as brief as possible and still give the critical information.)
--------------------------------------
What I stated in my original reply was: 'As the link given by kstrong indicates, it is not a myth and there is solid scientific research on the subject.'
You gave the link in which I gave the rose/milk research paper in that link. (In that thread you did not challenge my link.)
Yes, I gave a link on the bottom of the page (in my first reply in this thread) to a Google Scholar search using the key words 'milk treatment for mildew'. The keyworks are clearly stated by Google Scholar at the top of the first page. This was for additional information that there is a science literature for using milk to treat mildew, but as my written statement clearly indicates, I was referring to your link for the rose/mildew information.
-----------------------------------
I did not comment on your attempt to dismiss the patent science: 'Finally as a lawyer who does some patent work, I am very much aware that anyone can write anything they want in a patent application -- with or without basis.' Yes, even scientific publications can be fake. A golden test is to have published research results duplicated by a second independent study. In the present case, I have presented 2 studies, one in a journal and one in a patent. That should be enough but there is another patent. I selected the one because of the extensive experimental detail and because the one below used sunflower oil (I assume as a spreader sticker). Here is the other:

Title: Environment-friendly composition for preventing pests and diseases in crops.

Author: Jung, Byeong Yun. (S. Korea). Repub. Korean Kongkae Taeho Kongbo (2008), 7 pp. Patent written in Korean.

Patent Family Information

Patent No. Kind Date Application No. Date
KR 2008009479 A 20080129 KR 2006-69131 20060724
KR 835029 B1 20080603

Priority Application
KR 2006-69131 20060724

Abstract: 'The title compn. is composed of (by wt.%) at least one compd. selected from skim milk powder, soybean phospholipid, glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, calcium stearoyl lactylate, and yolk 0.005-0.405, sunflower oil 0.1-1.0, and water 98.995-99.895. The compn. is prepd. through adding the compds. into small amt. of water, stirring and mixing, adding sunflower oil, stirring and mixing, and adding water to dil. The compn. can be used for preventing and treating pests and diseases such as powdery mildew, downy mildew through evenly spreading the compn. on the leaves of crops (cucumber, lettuce, etc.) and flowers (rose, etc.). It is easy to directly prep. the compn. for farmers, and no odor is generated. The use of the compn. is easy.'
------------------------------------------
Not a scientific article, but still of interest (at least to me): I also came across one statement that: 'Milk kills powdery mildew so well that both home and commercial rose growers all over the world have adopted it for their fungicidal sprays.'

rofl. still nothing.

I was slightly disappointed in reading the myth links Perhaps I should of read the no need to water your roses just place a few Bayer aspirin at the base of each plant and it will cure all rose problems myth.

The second part of the original question was: "Also, how would this compare with baking soda/water combo?"

Unfortunately, I did not find any research papers that compared the 2 on roses. Contrary to what may think from some of the answers in this thread, there are research papers that report that baking soda does a satisfactory job concerning the rose mildew problem.

Here are 3 (from around the world):

Title: Effectiveness of antifungal compounds against rose powdery mildew (Sphaerotheca pannosa var. rosae) in glasshouses.

Authors: Pasini, Carlo; D'Aquila, Ferdinando; Curir, Paolo; Gullino, Lodovica.

Authors affiliation: Istituto Sperimentale Floricoltura, Sanremo, Italy. Crop Protection (1997), 16(3), pages 251-256.
Abstract: "The efficacy of several antifungal compds., chosen among salts, oils, plant exts., and of the hyperparasitic fungus Ampelomyces quisqualis, were tested in seven glasshouse trials against powdery mildew on roses. In the presence of a high disease incidence (55% of untreated leaves infected in six out of seven trials), all the antifungal compds. and the biocontrol agent A. quisqualis, applied individually, provided satisfactory control of powdery mildew. Most treatments were as efficient as the fungicide dodemorph, which, sprayed at weekly intervals, provided a 75% av. efficacy throughout the trials. Among the tests compds., KH2PO4, at 0.5 and 1%, offered good and consistent disease control, NaHCO3, at 0.5%, showed a satisfactory level of activity, while at 1% it was phytotoxic. Wine vinegar, applied at 5 and 10%, gave good control, but acetic acid was phytotoxic. JMS Stylet oil, canola oil, Synertrol and neem ext. provided satisfactory disease control. Fatty acids formulated as potassium salts significantly and consistently reduced powdery mildew severity, but caused some phytotoxicity. Milsana, a concd. ext. from leaves of Reynoutria sachalinensis, only partially controlled powdery mildew. Several strategies based on the rotation of different antifungal compds., with or without the application of dodemorph, provided very good, consistent disease control.
----------------------------------

AND

Title: "Efficacy of salts against fungal diseases in glasshouse crops."

Authors: Dik, A. J.; Van Der Gaag, D. J.; Van Slooten, M. A.

Authors affiliation: Applied Plant Research business unit Horticulture (PPO), Naaldwijk, Neth.

Published in: in Agricultural and Applied Biological Sciences (2003), 68(4b), pages 475-485.

Abstract: "The const. input of chem. fungicides against foliar diseases in glasshouse crops has instigated research on alternative control substances. Several bicarbonates, sulfates and phosphates were tested against powdery mildew fungi in cucumber, tomato, sweet pepper and rose and against Bremia lactucae in lettuce. The expts. were run according to EPPO guidelines for efficacy in glass-houses of Applied Plant Research (PPO). Plants were sprayed weekly and disease and yield were assessed. In cucumber, NaHCO3, KHCO3, MgSO4 and MnSO4 all reduced powdery mildew significantly, with MnSO4 as the most effective agent. In tomato, MgSO4, MnSO4 and KH2PO4 all reduced powdery mildew by approx. 40% whereas NaHCO3 and KHCO3 gave approx. 95% control. In pepper, NaHCO3 controlled Leveillula taurica by 50-90% compared to the untreated control. In rose, the efficacy of KH2PO4, MnSO4, MgSO4, NaHCO3 and KHCO3 against powdery mildew differed between cultivars. In general, the bicarbonates were the most effective compds. In lettuce, NaHCO3 reduced Bremia severity by 70 to 80%. Thus, bicarbonates can be a good alternative for control of foliar fungal diseases in glasshouse crops. The effective concn. is not causing any symptoms of phytotoxicity, provided that spraying is not done at high irradn. conditions. Bicarbonates have been submitted for the Dutch list of exceptions on the Pesticide Law."
-----------------------------------------------

AND

Title: "Control of powdery mildew with potassium bicarbonate and polyelectrolyte."

Authors: Hsieh, T. F.; Huang, J. H.; Hsieh, L. J.

Authors affiliation: Plant Pathology Division, Council of Agriculture, Agricultural Research Institute, Wufeng, Taichung, Taiwan.

Published in: Plant Pathology Bulletin (2005), 14(2), pages 125-132.
Abstract" "Sodium bicarbonate, potassium bicarbonate and ammonium bicarbonate were evaluated for their inhibitory effect on spore germination of three powdery mildew pathogens, Oidium neolycopersici, Erysiphe pisi, and Sphaerotheca pannosa. Data showed that the spore germinations of these pathogens were significantly (p------------------------------------

Perhaps a look at what Linda Chalker-Scott wrote in 2009 about baking soda will be useful in putting her articles in perspective (aside from the not updating aspect of her 2006 article concerning milk for mildew). Hint, what to look for - I interpret her presentation as "faint praise".

"This is all really fascinating, but what about rose diseases?
There are several articles in the scientific literature that
explore the efficacy of baking soda in treating rose diseases. Five studied the effect of sodium bicarbonate on powdery mildew. Though sodium bicarbonate reduced the mildew (Sphaerotheca pannosa var. rosae) attack in all five studies, suppression was short-term, not as effective as potassium bicarbonate, potassium phosphate, phosphate salts, or wine vinegar, and in one case was phytotoxic even in a dilute (1%) solution.
Better results are found when sodium bicarbonate is
combined with horticultural oil." Two groups of researchers
sprayed roses in the landscape with solutions of sodium
bicarbonate mixed with horticultural oil for treatment of black spot (Diplocarpon rosae). Both groups report the treatment to be effective in reducing, but not eliminating, powdery mildew, especially when disease pressure was low. The importance of an organic mulch to suppress disease inoculum (and thus depress disease pressure) was emphasized by one article. It is important to note that in both cases it was mixtures of sodium bicarbonate and horticultural oil applied, not simply baking soda."

No references are given.

Please look at her Table 4. For sphaerotheca "good to poor" is listed.

Please notice that none of the articles that I referenced concluded that supression was short term.

Also please notice that in my first article: "In the presence of a high disease incidence (55% of untreated leaves infected in six out of seven trials), all the antifungal compds. and the biocontrol agent A. quisqualis, applied individually, provided satisfactory control of powdery mildew." (I included this because of her statement ".... especially when disease pressure was low." )

I have a copy of the full Italian paper. I am permitted to distribute a limited number of copies for educational purposes. If anyone would like to read the full paper please e-mail me at kuska@neo.rr.com

The following is a scientific comparison of milk and baking soda on punkin.

Title: The effect of milk-based foliar sprays on yield components of field pumpkins with powdery mildew

Authors: Francis J. Ferrandino1, , and Victoria L. Smith2

Authors affiliation: 1Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, P.O. Box 1106, New Haven, CT 06504, USA

2Deputy State Entomologist, Department of Entomology, The Connecticut Agricultural Experiment Station, P.O. Box 1106, New Haven, CT 06504, USA

Abstract: "Previous work has shown that foliar applications of mixtures of cow's milk and water are effective in preventing powdery mildew (Podosphaera xanthii) of zucchini on greenhouse grown plants. Our own work on field-grown pumpkins indicated that the efficacy of such foliar sprays is highly variable. This study is an attempt to measure the effect of milk-based sprays on the yield components of field-grown pumpkins naturally infected with powdery mildew. Pumpkins (Cucurbita pepo cv. Howden) were grown for five seasons (20002004) at Lockwood Farm in Hamden, Connecticut under a wide range of environmental conditions and inoculum pressure. The experimental design consisted of five spray treatments arranged in 5×5 Latin squares. In order to minimize over-spray and interplot interference, an unsprayed buffer planting of a susceptible cucurbit separated replicates. Spray treatments were a conventional chemical control, no spray, 1% NaHCO3 (baking soda), and two milk-based sprays. Powdery mildew severity and plant growth were evaluated over the course of each season and marketable yield before and after a 20-day storage period was taken each year. Treatments based on milk were, on average, about 5070% as effective in reducing foliar symptoms and post harvest fruit rot and 4050% as effective in increasing marketable yield as the chemical control. Skim milk was not as effective as whole milk, especially in rainy years. However, both milk treatments consistently outperformed baking soda indicating that the mechanism of milk-based control of the fungus was not just based on its ability to buffer the pH of leaf surfaces."

Whe I read the above abstract, I wondered why the authors did not identify the "chemical control" so I obtained a copy of the full paper. The following describes the contents:

"The chemical control always included the protectant
fungicide chlorothalonil (1.6 kg a.i. ha1 Bravo 90DG,
ISK Pesticides Inc,. Memphis, TN) and a sticker spreader.
In addition, at every other spray date, starting at the first, one of the following systemic fungicides was also included in the in-tank mix: azoxystrobin (0.4 kg a.i. ha1 Quadris, Syngenta Crop Protection Inc., Greensboro, NC), myclobutanil (0.14 kg a.i. ha1 Nova, Dow AgroSciences LLC,
Indianapolis, IN), benomyl (0.9 kg a.i. ha1 Benlate 50WP,
DuPont Agricultural Products, Wilmington, DE), triadimefon
(0.1 kg a.i. ha1 Bayleton, Bayer Cropscience lp,
Research Triangle Park, NC) or no systemic fungicide.
These systemic fungicides were alternated to reduce the
possibility of the buildup of resistant strains. The milk and baking soda were normal grocery store type products. For
the first trial year (2000), the skim milk treatment was
replaced by a 50% aqueous solution of raw milk that
was obtained from a local dairy and was neither
pasteurized nor homogenized."

"In the first season (2000), fresh raw milk-based sprays were compared to the standard grocery store product. In the following 4 years (20012004), whole milk-based sprays (3.5% butterfat) were compared to skim milk-based sprays (0.5% butterfat) in order to evaluate the importance of fat content."

------------------------------------------------

In the "Results section" the following appeared:

"The data from the year 2000 indicate that there was no significant difference between disease levels in the whole milk and the raw milk treatments.
Overall results for the last four seasons (20012004) indicate that, although the efficacy of skim milk was slightly less than whole milk, the difference was not significant."

---------------------------------

In the "Discussion and Conclusion" section, the major results are the same as in the abstract. However, the following additional information may be useful to those living in certain climates.
"In general, milkbased sprays were most effective when inoculum pressure was low and disease came late in the season after flowering (2001 and 2002). In the last 2 years of this study, powdery mildew appeared early during the last week of July. In particular, 2004 was characterized by frequent periods of heavy rainfall during August, which made it difficult to keep the spray treatments on the foliage. The combination of high inoculum pressure and frequent wash-off resulted in loss of disease control (see Table 3: 2004)."

H. Kuska comment on year 2004, in Table 3 data. In the 2004 the control had a disease rating of 1963, baking soda had a rating of 1695, whole milk had a rating of 1715, skin milk had a rating of 1594 and the chemical control had a rating of 752. The authors indicated that the baking soda and milk differences where not significantly different in that year.

Also of interest to me was that in 2001 and 2003 the results for the chemical spray and whole milk spray were not significantly different (also from Table 3). These conclusions were determined by the authors with the use of a statistics program, with a criteria of p>0.005.

"To control powdery mildew, remove and destroy diseased material. During the growing season spray bushes with mancozeb, lime sulphur, tebuconazole, myclobutanil or triforine. Organic sprays contain bicarbonate of soda (potassium bicarbonate). Make your own spray by mixing one part full cream milk with ten parts water and spray at the first sign of the disease."

Bold print added by H.Kuska

The above quote is taken from a Government of Western Australia publication. see link below (that link last updated "Page last updated: Thursday, 11 December 2014" .

https://www.agric.wa.gov.au/pests-weeds-diseases/rose-problems?page=0%2C1

I'll give it a try again today. Here is a photo today from my Winnipeg Parks:

More before shots

Just sprayed

Ahh I see what's going on now, this is an older thread. At first I thought there were some interesting miscommunications!

Here is a specific 2011 study on just roses, "Control of powdery mildew (Sphaerotheca pannosavar. rosae) on rose (Rosa L. sp.) using anhydrous milk fat and soybean oil emulsions" - http://www.nzpps.org/journal/64/nzpp_641950.pdf

Anyhoo, wish me luck. I got nothing to lose but powdery mildew.

Wishing you luck prairie_northrose! PM not much of a problem here... Plus my only organic cure seems to work for all problems... (My Shovel...lol)

Thank you Jim! I'm moving this over to http://forums.gardenweb.com/discussions/3460144/m=23/powdery-mildew-and-milk-test-on-roses as I think it's a better forum for it.